In This IssueLenny studied with the first graduating class of restorative dentists and surgeons in the Branemark system from the University of Toronto in 1984. Lenny is the owner of

In This IssueThe Power of Light

Lingualized Occlusion for Implant-supported Full Acrylic Dentures

Applications of Removable Dentures in Biocompatible Resins

The Enormous Potential of Premium-Zirconium Oxide

and More ...

Vol. 7, No. 3 – Jun 2015

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dental labor international – Vol. 7 No. 3 – June 2015 3

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Trade Shows: a Survival Guide ....................................................34CE Credit Tests ..................................................................... 36-37Ad Link ...................................................................................... 38

4EditorialLenny Marotta, CDT, MDT, PhD

6The Power of LightAldo Zilio

Applications of RemovableDentures in Biocompatible ResinsMassimiliano Petrullo

22

The Enormous Potential ofPremium-Zirconium OxideHans-Jürgen Joit, MDT

28

Lingualized Occlusion for Implant-Supported Full Acrylic Dentures

José Ma Fonollosa Pla

32

16

Everything a Laboratory NeedsJay Black


4 dental labor international – Vol. 7 No. 3 – June 2015

Editorial

Lenny Marotta, CDT, MDT, PhD

I ’ve been working as a dental technician since I’m 13 years old. Mypassion has always been working with my hands sculpting andcreating beautiful crowns and bridges. . I like to make people

smile. After 50 years of working as a technician, owning a lab,achieving my CDT, MDT, and PhD, I see many modern productthat have changed the industry.

I remember in the old days we would joke, wouldn’t it be great ifwe could wax and cast a full gold crown that was tooth colored. Thismagic tooth colored alloy could be waxed, carved and cast like thecrowns we had been doing for years. Marginal integrity would beguaranteed and no metal collars. Contacts would be perfect andeasier to achieve. The occlusal anatomy would be dictated in thewax. All ceramic restorations have come and gone. The fits of manyCad/Cam zirconia crowns are far from that of gold. But finally, withthe advent of pressed ceramics we basically have achieved this goal.Modern lithium disilicate crowns are waxed and pressed rather thancast. For an old gold manlike myself it’s the best of two worlds. I cando what I have always done and get a crown that fits and marginsthat are the closest to a cast crown than any other all-ceramicrestoration. Pressed ceramics are one of my favorite restorations forthe simple fact that they are old and new technology wrapped up inone.

I have been making surgical guides for more than 25 years. In the80’s, we would just make a guide based on X-rays and tissue probingwith basically arbitrary holes for the surgeon. Later came softwarethat coincided with cat/scan imagery. We still placed our own pilotholes by hand but it was a little more precise since we had a scan toguide us in the lab. Now we have scanning guides, softwareprograms that can plan the most intricate implant designs, andsurgical guide that enable us to make framework prior to surgery.Seeing the evolution take place and being a part of it has been amost rewarding endeavor. I have worked chairside at NYU in the80’s with a patient in the chair for hours while we performedimmediate load provisional. Now we can do it in an hour with moreprecision and less complication. The future possibilities areboundless. Pre-making final abutments and final bridges anddelivering them at time of surgery will be a possibility.

The thing I find most rewarding today is my work withmaxillofacial and craniofacial appliances. I have been working withhospitals and in particular VA’s in making appliances to replaceskull plates, eyes, ears, noses, and whole faces. What a feeling it is tohelp our returning Vets regaining missing limbs vs. making anesthetic veneer bridge. Most of these cases are done at cost with nocharge at all, but to use my life long acquired skills to wax, sculpt,and design these appliance are the most rewarding thing I can dotoday. With the aid of digital scans and intraoral scanners I havebeen able to incorporate both the digital and handmade principlesof dentistry. I see limitless advancements in the combining of digitaland handmade dental and craniofacial prosthetics. I intend to spendanother 50 years achieving this goal. ■

Limitless Evolution

About the authorLenny Marotta graduated from the Kerpelschool of Dental Technology in New York City.Lenny continued his training through graduatestudies at Farleigh Dickenson University, wherehe focused on Gnathology and SubPeriosteal,Blade and Staple implants. He earned hisdegree in engineering from Farmingdale StateCollege, State University of New York. He has a

PhD from L.M.U. Leeds Metropolitan University in BiomedicalEngineering.

Lenny earned his CDT in four categories: Ceramics, Crown andBridge, Partials, and Dentures. Lenny is one of the founding membersof the Master of Dental Technology, ASMDT, program at NYU.

He is a Professor in Science and Technology Programs, School ofEngineering Technology, at Farmingdale State College, State Universityof New York.

Lenny is a Clinical Associate Professor in the Department of ImplantDentistry, Restorative and Prosthodontic Science, and the departmentof Biomaterials and Biomimetics at New York University College ofDentistry.

Lenny studied with the first graduating class of restorative dentists andsurgeons in the Branemark system from the University of Toronto in1984.

Lenny is the owner of Marotta Dental Studio and MDS Cranial FacialEngineering, which specializes in the fabrication of titanium medicaland dental implant prosthetics.




Aldo Zilio

The Power of LightTechnician and zirconia expert Aldo Zilio presents acase study of a large prosthesis made with themodern material

One recurring theme, that predominates but ishardly focused upon in our field, due to problemswith the techniques and materials involved and

their response through time, is the construction of largerehabilitations, whether ceramic or resin coated.

In fact, the progress made with regenerative materialsand techniques for some years now means that implantscan also be positioned in places where it used to beimpossible. Thanks to this clinical acceleration, we oftenmust resolve very complex cases in the laboratory in termsof both planning and technical problems.

There has been much debate about the best material toperform these rehabilitations. There are schools ofthought that favour the use of acrylic materials or acrylicmaterials with screw retained prostheses. My laboratorytends to favour cement-retained prostheses covered inceramic, as I feel that in addition to being unaesthetic, thethrough holes for the screw are very difficult to hide,especially when they are in the vestibular andinterproximal surfaces. This being the case, once closed,

they cannot be reopened without damaging thesurrounding ceramic. Both systems have limitations andweak points, but also several certainties. Composites andresins deteriorate very quickly due to their interactionwith absorbed liquids and with the functional forcescreated. On the other hand, although ceramics meet theseneeds excellently, there is a latent risk of them cracking orchipping. Lastly, we are working in opposite direction withobstinate perseverance that has various dimensions,almost forming two parallel worlds. As an alternative tometal ceramic, we have developed new workingtechniques in recent years using a relatively youngmaterial, zirconia.

From a strictly personal point of view I feel that there islittle new to say about composite or acrylic resins, the useand evolution of these materials both in stratifiedstructures to provide maximum individuality and in themore essential form as a monolithic technique, or forsomething else. However, there still remain greatopportunities to develop it and to obtain ‘ideal’ solutions.

Fig. 1 Fig. 2



The factor of time Are the passage of time and changing technology such importantfactors? Presented here is the first of three cases - six years havepassed between them all actually starting and finishing. A sector likeours with a large technological content is defined by a long-termcommitment.

However, we have actually seen how technology has beenrelegated into second place behind the human factor, which stillremains the most important thing, the dental technician’sknowledge and ability to plan and then make the prosthesis byapplying the maximum of professionalism in his work.

All three cases were made using highly translucent zirconia. Thismaterial allows completely different structures to be developedcompared from those of the past. The relevant translucence, which is

high, has a positive influence on the interchange with the light,making the volume of the bridge framework seem larger,consequently favouring the protection of the ceramic from theocclusal loads and from the cutting forces, especially in the posteriorsectors.

Case studyNow we are going to present a case in which it was necessary to carryout surgery to increase the osseous volume in the upper frontal area,so that implants able to support a 12-element arch could be inserted.The patient had worn a total prosthesis for a total of 20 years and aprocess of osseous atrophy had set in during this period that causedsignificant reabsorption and consequent alteration in the lipvolumes and in the position of the maxillary (Figures 1-8).

Figs. 1-8 — Initial situation, increasing the volume of anterior bone

Fig. 3 Fig. 4

Fig. 5 Fig. 6

Fig. 7 Fig. 8



The notable shortage of osseous crest in the frontal area of theupper was compensated for by fitting two parts of bone from thebone bank, which were connected and fixed using small titaniumscrews, while the maxillary sinus was raised. After the time requiredfor biological integration, the screws were removed and six implantswere placed.

The lower presented fewer problems. In fact, four implants wereapplied using the All-in-four technique, two in the frontal area andtwo in the LL5 and LR5 positions, inclined distally so as to supportthe distal load of the future extension (Figures 9-16). The prosthesiswas made once the wound from the surgery had healed.

Since the implants were the external hexagonal type, it wasdecided to construct a fixed structure made of highly translucentzirconia with the connections entirely made of solid zirconia. So theimpressions and the correct vertical dimensions were taken as usual.

The first laboratory analysis allowed us to plan the definitivestructure by fitting artificial prosthetic teeth on composite resinrisers. We noted significant atrophy in this phase that had begunseveral years beforehand.

In fact, the restoration of the correct vertical dimension puts usin a position to have access tunnels for very long screws.Furthermore, the hole for screw retention of the three upper frontalimplants falls vestibularly, notwithstanding the considerable increasein volume obtained in this area (Figures 17-19). Moreover, wedetermined ideal aesthetics by mounting our teeth according to theclassic aesthetic and phonetic canons, especially in attempting toprovide adequate support to the lips. This was confirmed in thesubsequent verification. The fitting of the teeth satisfied both ourexpectations and especially those of the patient.

Fig. 9 Fig. 10

Fig. 11 Fig. 12

Fig. 13 Fig. 14




Figs. 17-19 — In the maxilla, large posterior abutments wererequired to restore the correct vertical dimensions

Figs . 9-16 — After healing impressions were taken and models made. Laboratory work begins on the lower prosthesis working arounddistally inclined abutments in the LL5 and LR5 positions

Laboratory workUpon returning to the laboratory, the job was waxed using thecorrect volumes of tissues and then duplicated using silicone. Themetal replicas of the implants were inserted and then theduplications were glued using extremely low expansion polyurethaneresin. Perfect and stable copies of the two arches were obtained afteran hour. A small refinement of the borders was made, and the accessholes, previously found using wax casting sprues with the help of amask, were uncovered.

At this point we were able to send the rigid precise structure tothe dental practice. We have already seen the concrete advantage ofbeing able to test a true prototype of what will be the definitiveprosthesis. In such a complex case as this checking the occlusion forthe possibility of milling rigid surfaces like those is of fundamentalimportance. Furthermore, the relationship with the tissues and thespaces allowing hygiene to be maintained can be checked, and theycan be modified by addition or subtraction.

Fig. 15 Fig. 16

Fig. 17

Fig. 19

Fig. 18

Taking a radiograph during this test to check the implants’passivity is always a good idea and they can be repositioned easily bysectioning the polyurethane and fixing the implant in its newposition.

Once this important check has been carried out, we have all themain elements to carry out the work. We decided to create threeindividual prepared teeth in the frontal area made completely ofzirconia with anti-rotational internal hexagon in order tocompensate for the unfavourable axis of insertion. We planneddirectly screw-retained structures on the head of the implant in theremaining upper implants. The lower and upper implants in theposterior area were prepared like the prepared teeth to which acement-retained crown was applied after screw retention of theprimary structure. This was due to the excessive length of thetunnels making screw retention in the presence of the occlusal tablesimpossible.

The three prepared teeth were made first, and then oncesinterised and finished; they were fitted inside the resin structurethat was in turn milled and sinterised. The sintering is preceded bythe usual crude colouring with the relevant dentinal colours oforange, violet etc, and two shades of pink in the gingival parts(Figures 20-31).

Finishing artistryFollowing the usual check of the passivity and a thorough check ofthe centricity, the job was taken to the laboratory. At this point weproceeded to the final finishing after which we carried out our high-temperature wash, white and pink, following the previouslydescribed methods.


Fig. 20 Fig. 21


Figs. 20-25 — The lower prosthesis, to be retained by four screws

Fig. 22 Fig. 23

Fig. 24 Fig. 25

Fig. 26

Fig. 27

Then the pink parts were stratified using at least three types ofcolouring (dark, light, and medium). As we have seen, the gingivalmasses must be absolutely opaque and not too translucent.Personally, I prefer to add some areas of transparency and variousrelatively white parts as in the usual stratification. These areas aswell. Then two or three firings are carried out, depending on theextent and difficulty of the work.

The pink parts can also be finished by small additions madebefore each firing of the white areas. This method allows me tocomplete the stratification of the dental elements with fully formedartificial tissues and without further risk of aesthetically unpleasantshrinkage or loss that is difficult to control (Figures 30-34). Oncethis had been concluded, we began the complex phase ofconstruction of the whole dental and tissutal architecture of therestoration that we are going to check on the patient. If the initialplanning phase has been carried out carefully, there will be nosurprises.

There was total correspondence with the functional-aestheticparameters. The patient was absolutely satisfied with the workcarried out up to this point.



Figs. 26 and 29 — For the upper prosthesis, the three prepared anterior abutments were placed within the structure, with screws to secureit to the remaining three implants

Figs. 32-34 — Details of the veneering

Figs. 30 and 31 — Restorations in place, showing the holes for retaining screws

Fig. 28 Fig. 29

Fig. 30 Fig. 31

Fig. 32 Fig. 33

Fig. 34

Final adjustmentsAfter an occlusal check-up and a small amount of refining, the workwas sent back to the laboratory accompanied by photographs andcentring by refitting that helped us to finish the work, taking care ofthe functional and aesthetic aspects (Figures 35-40) as well as all thedetails, following this, all of the basal areas were smoothed andpolished into what must basically be a convex shape in order toavoid bacterial plaque developing.

From this point of view too, zirconia demonstrated its superiorquality once again. In fact, once polished to mirror image standard,we are faced with an absolutely compact surface, impregnable by any


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Figs. 35-37 — The long tunnel access to the screws on the mandibular prosthesis were covered with crowns, which were be cemented over the screws

Fig. 35 Fig. 37Fig. 36

Fig. 38

Fig. 39

Fig. 40

Figs. 38-40 — The final views showing the stratification and fit

agent that may operate in the oral cavity. The final firing of work ofthis size presents several problems. In addition to a good pre-polishing, in order to obtain the desired brilliance, in my opinion alayer of appropriate glaze is needed on the areas to be polished,producing a surface that is all alike in such a large arch isunthinkable. My idea is to bathe the entire surface with stain liquidand preferably leave it to penetrate in depth for several minutes. Inmeantime, the make-up operation can be started using the surfacecolours.

About the authorAldo Zilio graduated as a dental technician in Mestrino (Padova,Italy) and has run his own private laboratory in Creazzo (Vicenza,Italy) since 1984. He is a lecturer for the National Association ofDental Laboratories in Italy (ANTLO). He lectures internationally,acts as technical advisor for leading dental companies and is theauthor of several international publications, including the book‘Zirconia the power of light’.

The placing of glaze paste in the basal and interdental spaces isindispensable and there are very suitable commercial pastes for thisuse. The aim during the subsequent mechanical polishing is to sealand vetrify the areas that are not so easy to reach. We are going toconnect the indispensable addition of small portions of ceramic bymixing masses with a low casting point with high-value enamel andcoloured dentine.

However accurate our work, it is very clear that small correctionsare also always going to be needed in this phase. Following this wewere able to proceed with the firing.

Each piece is unique so there are no pre-programmed fixedtemperatures. The factors that have combined to create the resultsuch as the size, thickness, number of firings, must be taken intoconsideration.

In general, it is better to obtain an 80-90% surface compared tothat desired in the most smoothed and polished areas and thencomplete the remaining percentage with mechanical polishing. Sothe Job was finished consigned. As can be seen in the images, thefinal solution is first cemented to the three zirconia prepared teeth inthe upper frontal part using silicone-based removable cement andscrew-retained to the other pillars at the same time. Lastly, the fivecrowns that close the occlusal holes are fixed in place. This type ofsolution does not satisfy me at all as it exposes us to the risk ofoccasional decementation, or in contrast, to a certain degree ofdifficulty in removing the crowns if and when necessary. Aspreviously mentioned, given the unusual length of the access canals,this technique was adopted in order to allow screw retention. In myopinion, it is better to completely stratify the whole arch whenpossible. ■


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905.489.1970 ext. 206 / 207 • 1.866.581.8949 • [email protected] • www.dtacanada.com

Dental Morphology • Dental Anatomy Theory Wax-up Technique for Anterior and Posterior

Temporary Restoration • Implant Model Work Soft Tissue Removable and Stone Tissue• Denture Set-up / Smile Balance• Occlusion / Function• Immediate Loading Provisional• Use fo the Fiber Force Material• Temporary Restoration in Acrylic / Composite Screw-retained• Flask Technique• Internal Layering Technique Dentine / Internal Stain / Enamel• Inspired by Nature• Pink Tissue Build-up Technique

CAD/CAM Technology • Introduction CAD/CAM Technology / CAD Design Customized vs. Standard CAD Design / CAM Milling Restoration

All Ceramic Restoration • Model Geller Technique for Refractory Dies• Veneers Feldsphatic Refractory Technique Veneers / Crowns Press Layered and/or

Stain Technique• Lithium Disillicate vs. Leucite Reinforced• Zirconia Layered and/or Stain Technique

Implant Restoration • Press to Metal Cemented Retained• Traditional Technique PFM Screw-retained with Pink Porcelain• Wax-up Technique• Casting Technique• Porcelain Build Technique Internal Live Technique Inspired by Nature• CAD/CAM Technology Titanium Bar with Individual Crowns Cemented Retained and

Pink Composite• All-on-4™ Technique Using Denture Teeth, Pink Acrylic Customized with Pink Composite• Customized Bars CAD/CAM Technology

Cascione Flyer-CS4.indd 1 2015-05-06 6:21 PM


Full acrylic dentures include full dentures, as well as overdentures and hybriddentures.In all cases, a plastic material based on acrylic resin is used to restore the soft

tissue and fabricate artificial teeth.Our author José María Fonollosa demonstrates just how important a role

lingualized occlusion can play in implant-supported full dentures.

José Ma Fonollosa Pla

Lingualized Occlusion

The term overdentures refers to removable partial or fulldentures that are placed over one or more remaining teeth,tooth roots or osseointegrated implants.

In order to fabricate implant-supported overdentures, it isessential to classify the dentures in question in accordance with thetype of support, prior to fabricating the supporting elements (axialanchoring elements and bars) or selecting the most appropriateocclusal concept . This type of classification allows the dentures to bedivided into three categories based on the number and position ofthe implants[2]: mucosa-supported dentures (Fig. 1) are those that are,in principle, only supported by the mucosa; implant-supporteddentures (Fig. 2) are supported exclusively by implants; and implant-mucosa-supported dentures are supported by the mucosa as well asby implants (Fig. 3) [3]. Full dentures are mucosa-supported dentures,while hybrid dentures, as a permanent form of restoration, shouldbe viewed as implant-supported dentures. This article looks at

lingualized occlusion in the types of denture mentioned, what thisconcept actually means, when it is indicated, and whatcharacteristics a tooth should have in order to enable this occlusalconcept to be implemented.

Lingualized occlusionLingualized occlusion can be described as a type of occlusion wherethe palatal cusps of the maxillary dentition dovetail with themandibular occlusal surfaces in terms of centric relation, workingcusps and non-working cusps [1]. As a result, occlusal contact betweenthe maxillary palatal cusps and the fissures of the mandibularantagonists only occurs in one area, and the mandibular buccalcusps as well as the corresponding occlusal surfaces of the maxillaryantagonists remain free, in other words without any contact (Fig. 4).As early as the beginning of the 20th century, Gysi was the first to

refer to the biomechanical advantages of occlusion-appropriate

Fig. 1 — The bar as a supporting element for mucosa-supported dentures Fig. 2 — Implants as the supporting element forimplant-supported dentures

for Implant-Supported Full Acrylic Dentures



tooth-shaping aimed at enabling improved denture stability based oncontacts that run vertically to the alveolar ridge[4]. For this purpose,he designed special teeth for use in the case of malocclusion (crossbite), which he arranged to have patented in 1927 under the name"Cross-Bite Posterior Teeth".

The maxillary posterior dentition featured just a single cusp thatdovetailed with the fissures of the relevant mandibular antagonists.

This resulted in the vertical transmission of force to the alveolarridge, which already constituted lingualized occlusion even beforethe term existed. During the same period, French also noticed thebenefits of a concept that could be described as lingualizedocclusion[5]. In 1935, he arranged to have his "Modified PosteriorTeeth" patented. The maxillary dentition in this case included a widefissure while the mandibular dentition featured a narrow and flatmasticatory surface. This anatomical surface, which corresponded to

the "mortar and pestle" principle of contact, also enabled thetransmission of vertical forces to the dentures.

However, the theories of Gysi and French were not particularlyconvincing until 1941, when Payne created a setup technique basedon the principles of lingualized occlusion and described it in hispublications[6]. According to Payne, the cusps of the maxillaryposterior dentition must be at an angle of 30 degrees in order toachieve lingualized occlusion and to retain contact with themandibular dentition in the case of eccentric movement. Bycontrast, the buccal cusps of the maxillary dentition should not haveany contact with their antagonists during mandibular movement.

According to Payne, this type of setup offered three particularlyimportant benefits:

1. Lingualized occlusion provides balance in the case of a cross bite. According to Payne, the result in such cases was improved denture stability and greater wear comfort for the patient.

2. As contact between the maxillary palatal cusps and the posterior mandibular dentition only remained in one area, the lateral forces were reduced. This minimized the potentially adverse effect of the lateral forces.

3. The vertical forces were directed centrally to the mandibular alveolar ridge. The effect of these vertical forces is considered beneficial for the stability of the dentures and for long-term support via the hard and soft tissue of fully edentulous jaws (Fig. 5).

Fig. 3 — Model of subsequent implant-mucosa-supported dentures

Fig. 5 — The maxillary palatalcusps occlude vertically to the

alveolar ridge

Fig. 6 — Pound's line: from the trigonum retromolare regionup to the mesial surface of the canine

Fig. 7 —According to Pound, buccal contact must be avoided inlingualized occlusion

Fig. 4 — Lingualized occlusion: no buccal contact



At the beginning of the 1970s, Pound, to whom the term"lingualized occlusion" is attributed, developed this same concept innumerous articles[7, 8]. Pound believed that the problem of denturestability could be solved by establishing correct buccolingualpositioning of the dentition. From his point of view, stability of thiskind could only be achieved through the principle of tooth setup ontop of the residual alveolar ridge.

According to Pound, studies of natural dentition showed that thelingual surfaces of mandibular posterior dentition are positionedbetween two slightly diverging imaginary lines that begin on themesial proximal surface of the mandibular canine and run towardsthe back: one along the lingual surfaces of the mandibular posteriordentition up to the lingual surface of the tuberculum retromolare(known as Pound's line), and another in the central area of themandibular posterior dentition through the region known as thetrigonum retromolare [7] (Fig. 6).

Fig. 8 — Steep maxillary cusps in order to retain shearing andgrinding function

Fig. 9 —The flat buccal cusps of the mandibular dentition prevent anydestabilizing contact

Fig. 10 —The broad fissures ensure sufficient freedom of movement (long centric)

Fig. 11 — The buccal surfaces facilitate cheek contact thathas a stabilizing effect

This position, which is independent of the type ofocclusion, occurs as a result of functional alignment duringgrowth and facial development as a result of the reciprocalpressure of the tongue, on the one hand, and of the buccalmuscles on the other.

This functional position of the mandibular posteriordentition determines the position of the maxillarydentition.

According to Pound, a further important aspect in thestabilization of dentures is the development of occlusal shaping thatstops lateral forces from occurring between the buccal cusps of themaxillary and of the mandibular dentition, in order to prevent thedentures from shifting in this direction.

Like his predecessors, Pound also avoided contact between thebuccal cusps during eccentric movement of the lower jaw by millingthe buccal cusps of the mandibular dentition rather than the buccalcusps of the maxillary dentition (Fig. 7).

Although this technique was a little different than that describedby Payne, it allowed him to achieve very similar mechanical results asthe masticatory forces were thus shifted to centric relation and thelateral forces that counteracted denture stability were reduced.

According to Pound, this resulted in "lingualization" of theocclusion where only five contact points from the maxillary palatalcusps were used on either side.

In cases of lingualized occlusion, Pound used dentition with acusp angle greater than 30 degrees in the upper jaw and of 20

Fig. 12 — Esthetic and functionally-appropriate combination with PHYSIODENS anterior teeth



degrees or less in the lower jaw in order to obtain effective shearingand grinding function during consumption of food (Fig. 8). This wasfollowed by various articles from other authors such as Murrell[9],Becker[10] and Ortman[11] on the concept of lingualized occlusion thatdiscussed issues such as new tooth molds, setup protocols andprocedures for adjusting occlusion. Just a few years later, severalauthors suggested small deviations from these principles[12], forexample such as "minimal contact" between the maxillary andmandibular buccal cusps on the working side as well as in the case ofprotrusion, in order to ensure balance during these movements.The articles by Gerber on occlusion in full dentures are

particularly interesting[13, 14]. With regard to occlusion in the case offull dentures, Gerber suggests that occlusal stability when chewingbolus should be resolved through specific shaping of the aggregatemasticatory surface. According to Gerber, "As the effect ofcalibration or what is known as multipoint contact, lessens whenbolus is located between the dental arches, the possibility ofstabilizing the dentures using any pair of antagonists in the molarregion must be provided."[15]. In order to solve this problem, Gerbercreated the concept of "multi-site, autonomous masticatory stability",which has the following primary characteristics:• Setup adapted to the alveolar ridge through a larger masticatory surface at the lowest point of the mandibular alveolar ridge. • Precise introduction of angled planes in the masticatory surface of the dentition for the purpose of stabilization. As a result of the load placed on the overall surface due to bolus, the exterior slopes of the buccal and palatal molar cusps generate a vector component of the masticatory forces in the palatal direction that pushes the dentures against the denture-bearing area.• Avoidance of destabilizing, skew planes on the masticatory surfaces of the dentition, for example by shortening the buccal cusps that cause the dentures to lift when a load is applied, if the alveolar ridge is in poor condition. The goal is "lingualization" of the occlusion in order to improve stability. In accordance with his condylar theory, Gerber assumes the existence of a cusp-fossa relationship for posterior setup, based on the "mortar and pestle" principle. Efficient mastication is

Fig. 13 — Esthetic and functionally-appropriate combination withcharacterized VITAPAN anterior teeth

Fig. 14 — Even distribution of the occlusal forceswith maximum intercuspation

achieved with a minimum of three antagonist pairs per side in a cusp-fossa relationship, and with contact during empty lateraland protrusive movement. Gerber also argued in favor of freedom of movement of the incisors and canines of at least one millimeter as "the immediate contact of these teeth in the case of protrusive and lateral movements can place an excessiveload on the anterior areas of the alveolar ridge, thus destabilizing the dentures. Particularly unfortunate in the case of full dentures is the anterior-canine guidance that often occurs naturally in young dentition"[14].

Overall, this gives rise to the following basic principle oflingualized occlusion: the tooth setup is distinguished by theocclusion of the maxillary palatal cusps with the fissures of themandibular antagonists, both in eccentric and centric relation.The vestibular mandibular cusps do not have any contact with

the maxillary cusps either in centric or in eccentric movements.

Dentition for lingualized occlusionFollowing analysis of the lingualized occlusion, we now need to lookat the appropriate acrylic teeth for this concept.Today it is no longer necessary for these to be ground or

reworked as some authors suggest, as teeth are already available onthe market that meet the requirements of a lingualized occlusalconcept.The LINGOFORM teeth from VITA are especially worth

mentioning. They are particularly suited to implant-supporteddentures and full dentures with a balanced or anterior-guidedlingualized pattern of occlusion.

• In this respect, it should be noted first of all that they are fabricated using acrylic materials such as networked monomers, which provide the tooth with a high density and thus high shade stability. Moreover, they contain anorganic microfillers that provide for greater mechanical load capacity and increased resistance to abrasion. Both aspects are very important in implant-supported dentures as the antagonists are often comprised of harder materials (such as ceramic or dental enamel) than conventional acrylic teeth. This contact



causes the material to wear quickly, resulting in a loss of vertical dimension and in reduced efficiency during mastication. It is therefore essential that teeth are used that offer high abrasion resistance, that avoid this type of wear, and that retain the appropriate vertical dimension for the patient, thus maintaining efficient mastication by maintaining the gradient of the masticatory surface.

• As suggested by the fathers of the concept of lingualized occlusion, Payne and Pound, the maxillary palatal cusps are raised in order to improve masticatory efficiency when shearing and grinding food, while the mandibular buccal cuspsare lower in order to prevent destabilizing contact with the maxillary buccal cusps (Fig. 9).

• The mandibular posterior teeth have a wide fossa in order to ensure freedom of movement – in other words, a long centric – with the aim of preventing the horizontal translation forces that can be so detrimental to the health of underlying bone structure, and in turn, to retention of the implants (Fig. 10).

• The dimensions of the buccal surfaces enable optimum cheek contact that encourages denture stability (Fig. 11). The lingualized alignment and the shaping of the mandibular palatal cusps establish more room for the tongue, which also improves stability.

• From an esthetic perspective, they are perfectly tailored to the PHYSIODENS (Fig. 12) and VITAPAN anterior teeth (Fig. 13)in terms of shade and morphology.

Occlusion in the case of full acrylicdenturesThis occlusal concept, which is particularly indicated for thefabrication of full dentures and has been used frequently for manyyears[16], ensures that during mastication, the forces applied to themasticatory surfaces are always directed in the lingual direction andtransmitted to the mandibular denture, so that this occlusalrelationship provides even greater stability for masticatoryfunction[17]. The aim of this occlusion is to lend greater stability tofull acrylic dentures. For this purpose, all buccal contact with thealveolar ridge, which generates a considerably destabilizing force in

the opposite direction on the antagonist side, is avoided, and theattempt is made to direct the occlusal forces on to it vertically. Inrecent years, the concept of lingualized occlusion has also been usedas an ideal occlusal pattern in full acrylic dentures for mucosa-supported, implant-supported and mixed restorations [18, 19, 20]. Forthese dentures, it is necessary from the point of view of occlusion todistribute the occlusal forces evenly across the entire dental arch withmaximum occlusion[21] (Fig. 14). In addition, the forces must bedirected axially onto the implants in order to prevent damaginglateral forces. Accordingly, parafunctional habits that generatesubstantial lateral forces are portrayed as the primary reason forbone resorption processes and for implant failure[22]. Moreover, theconcept in question also makes it easier to grind the food bolus[23]

(Fig. 15).Dentures on osseointegrated implants can generate the same

occlusal forces as natural dentition[19,24]. This is made more difficultby the fact that these are neither cushioned by the periodontium norrestricted by proprioceptive function. These occlusal forces, whichare transmitted directly via the cusp angles of the posterior teeth inthe case of eccentric movements, generate lateral forces and can thushave a hugely destructive effect on the implants depending on theirintensity.

On the other hand it has been shown that the masticatory forcesin the anterior area only make up one eighth of the forces occurringon the second molar [25]. The recommendations for permanent,implant-supported dentures (in this case, implant-supportedoverdentures that are similar to permanent dentures in terms oftheir biomechanics), and for hybrid dentures, are therefore occlusionwith anterior guidance or group-function guidance with disclusionin the posterior area and lingualized occlusion[16,19] (Fig. 16). On thebasis of these assumptions, the ideal occlusal concept for these typesof denture is one that facilitates contact of the posterior dentition incentric relation with immediate disclusion in the case of eccentricmovements:

• In centric relation, slight contact between the cusps and the central fossa should result

• Anterior guidance: canine guidance or group function withoutinterference of the posterior dentition

• Axial load on the implants[26]

Fig. 15 — The implemented concept makes it easier to grind the food bolus Fig. 16 — Anterior guidance



In the case of mucosa-supported or mixed (mucosa/implant-supported) full acrylic dentures, bilaterally balanced (Fig. 17)anteroposterior (Fig. 18) and lingualized occlusion is recommendedas the occlusal concept (Fig. 19)[17]. In fact, numerous authorsrecommend the use of this type of occlusion in combination withwide fissures that facilitate full freedom of movement ("longcentric"), without anterior contact in centric relation [2,10–12]. The goalof this occlusal pattern must be to achieve slight bilateral contact ofthe anterior and posterior dentition during excursive movements oftwo to three millimeters outside of centric relation (Fig. 20), and thisas a result of slight compensation curves (thanks to the considerableheight of the maxillary buccal cusps) that are necessary for thecondyle curvature. ■References:1. The glossary of prosthodontic terms. The academy of prosthodontics. J

Prosthet Dent 2005, Band 94: 10-92.2. Wismeijer D., Van Waas M.A.J, Kalk W. Factors to consider in selecting an

occlusal concept for patients with implants in the edentulous mandible. JProsthet Dent 1995, Band 74, 4:380-384.

3. Van Waas M.A. et al. Dutch consensus on guidelines for superstructures onendosseous implants in the edentulous mandible. J Oral Implantol 1991; 17:390-392.

4. Gysi, A., Special teeth for cross-bite cases. Dent Digest 1927;33:161-171.5. French F. A., The problem of building satisfactory dentures. J Prosthet Dent

1954;4:769-781.6. Payne S.H., A Posterior Set-up to Meet Individual Requirements. Dent Digest

1941; 47: 20-2.7. Pound E., Utilizing speech to simplify a personalized denture service. J Prosthet

Dent 1970; 24: 586-600.8. Pound E., An introduction to denture simplification. J Prosthet dent 1971;

6:570-580.

Fig. 17 — Bilaterally balanced occlusion Fig. 18 — Anteroposterior occlusion

Fig. 19 — Lingualized occlusion Fig. 20 — Slight bilateral contact of the anterior and posteriordentition during excursive movements

9. Murrell G.A., The management of difficult lower dentures. J Prosthet Dent1974;32: 243-250.

10. Becker C.M. et al., Lingualized occlusion for removable prosthodontics. JProsthet Dent 1977; 38:601-608.

11. Ortman H.R., The role of occlusion in preservation and prevention in completedenture prosthodontics. J Prosthet Dent 1971; 25:121-138.

12. Lang B.R., Razzoog M.E., Lingualized integration: tooth molds and an occlusalscheme for edentulous implant patients. Implant Dent 1992;1:204-211.

13. Gerber A., Geometrische oder funktionelle Prothetik? [Geometric or functionalprosthetics?] Schweiz. Monats. F. Zahnheilk. [Swiss Dental Monthly] 61:1055-1062. 1951

14. Gerber A., L'oclusion et l'articulée naturelle et prothétique. [Natural andprosthetic occlusion and articulation] Zurich. Condylator service, 1960.

15. Geering A.H., Kundert M., Atlas de prótesis total y sobredentaduras. [CompleteDenture And Overdenture Prosthetics] Barcelona: Salvat, 1988.

16. Parr G.R., Ivanhoe J.R., Oclusión lingual: una oclusión por todas las razones.[Lingualized occlusion. An occlusion for all reasons] Clínicas odontológicas deNorteamérica [Dent Clin North Am] 1996; 1:107-117.

17. Hiroshi M. et al., Sobre la pista de la oclusión lingualizada en el ámbito de laprótesis total. [On the track of lingualized occlusion in the field of totalprosthetics] Quintessence técnica 1994; 7:391-415.

18. Bernier J., Rehabilitation of the Edentulous Mandible: Implant-supportedOverdentures. Oral Health 2006.

19. Reitz J.V., Lingualized occlusion in implant dentistry. Quintessence Int. 1994;3:177-188.

20. Davies S.J. et al., Good occlusal practice in the provision of implant borneprostheses. British Dental Journal 2002; 191:79-88.

21. Lekholm U., Clinical procedures for treatment with osseointegrated dentalimplants. J Prosthet Dent 1983;50:119.

22. Hobo S., Ichida L., García L., Osseointegration and Occlusal Rehabilitation.Chicago: Quintessence, 1989; 258:323-325.

23. Phoenix R.D., Engelmeier R.L., Lingualized occlusion revisited. J Prosthet Dent2010; 104: 342-346.

24. Haraldson T., Chewing efficiency in patients with osseointegrated oral implantbridges. Swed Dent J 1979; 3:183-191.

25. Ramfjord S., Ash M., Occlusion. Philadelphia: Saunders, 1971:108.26. Norton M., Fixed bridge rehabilitation. In M. Norton, Dental Implants: A Guide

for the General Practitioner. 1st Edition, P. 81-104. London: QuintessencePublishing Co. Ltd., 1995.



Applications ofRemovable Dentures inBiocompatible ResinsMassimiliano

Petrullo

Introduction

The dental composite resins are among the most common materialsfor the production of dentures and orthodontic appliances. Withoutany shadow of a doubt, the PMMA resins are the most frequentlyused which, as it is commonly known, involve a number of practicalproblems and a low biocompatibility level for patients [1-3] andoperators [4-6].

Over the years, many have been the attempts to replace the

PMMA-based resins for the previously mentioned reasons, but theresults obtained have always been unsatisfactory. Today, on the basisof the work performed by the applied research program TRE,accompanied by a large series of clinical cases and supported by therelevant experimental data [7-12], we believe that the technology we usestarts this revolution, that is to be able to enter into a new era in theproduction of dental composite resin devices. Below are describedthe most advantageous and prominent aspects of VLC resin devicesin removable dentures.

Fig. 1 — dentures implanted in wax before finalization. Fig. 2 — dentures transformed in resin before polymerization.

In this article are described the applications in removable dentures of a new generation of visible lightcuring resins (VLC), which today can replace completely the self or heat-cured poly-methylmethacrylate (PMMA) in all the fields in which they are employed. These procedures areincluded in the applied research program TRE, which involves the use of these materials in fixeddentures and orthodontics as well. In this work the aspects concerning the removable dentures willbe examined, underlining the key differences between VCL and PMMA materials.



Materials and Methods

One of the most important application field of dental compositeresins is the production of removable dentures in the followingprocedures: full dentures; overdenture; immediate dentures; pre-extraction dentures; partial and combined dentures; repair andrelining.

The works described here have a large series of clinical cases andhave been made with protocols developed by the author,Massimiliano Petrullo, and certified by the manufacturer of thistechnology, DENTSPLY int. Prosthetics Division.

Full Dentures

The procedure has the classical steps of a linear technique, madewith VLC materials also in the intermediate phases (trays, baseplates) which make the outcomes of registration until the finaldefinitive test more precise and predictable thanks to their precision.Once obtaining the positive feedback, we finalize the dentureproduction with the specific VLC materials. Due to the absoluteprecision and repeatability of the procedure in all its operating steps,the transformation requires no mold and is controllable in eachphase, avoiding the usual re-intervention once the dentures have

Fig. 3 — polymerized dentures. Fig. 4 — dentures completed

Fig. 5 — overdenture. Trial in wax Fig. 6 — overdenture completed.

Fig. 7 — articulating models Fig. 8 — upper dentures completed



been completed, which would nullify the quality of the finalproduct, in particular for tooth surfaces (Figs. 1-4).

OverdentureUsing this procedure we can fix the connections on the dentalmodel so that their precise positioning can already be verified in thepreliminary phases; the possibility of fixing the connections in thelab avoids complex relining phases in the oral cavity with resins,which are usually polymerized in the incorrect manner (Figs. 5,6).

Immediate and Pre-Extraction DenturesThe absence of a residual monomer is fundamental for this type ofprocedure, as it guarantees an optimal tissue healing even in thecases of open wounds and immediate dentures delivery. The systemallows the possibility of using relining materials without monomeralso in the postoperative phase. These procedures can indifferentlybe used in tissue-supported or implanted dentures (Figs. 7, 8)

Partial DenturesDuring the direct modeling it is possible to control the resin beforepolymerization; thanks to this possibility it is now possible to bettermanage thickness. Another significant advantage is to prevent theresin from entering undercuts; upon polymerized device removal,this problem generally involves the loss of model reference pointsduring finalization phase (Figs. 9, 10).

Combined DenturesThe characteristics of these materials provide excellent connectionsbetween the movable and fixed parts (Figs. 11, 12).

Repair A fundamental characteristic which dentures must generally have isthe possibility of having easy readjustments and simple repairing;with this type of resin everything is much easier and repairing giveexcellent results in terms of resistance and durability (Figs. 13, 14).

ReliningWhat has been said for repairing can also be said for relining; theuse of program TRE involves materials which can be used directly bythe clinician and indirectly in the lab. Both procedures guaranteeperfect results in terms of precision and adhesion. It has to beunderlined that the direct procedure allows the patients to avoid theunpleasant sensations provoked by self-curing PMMA materials(Figs. 15, 16).

DiscussionFrom the technical viewpoint the procedures above describedregarding the use of VLC materials appear much more simplifiedwhen compared to conventional materials and affect in no way theusual clinical procedures; dentures made with VLC materials offer avery high biocompatibility level which, together with better

Fig. 9 — implant with applied resin Fig. 10 — implant completed

Fig. 11 — combined dentures completed Fig. 12 — fixed connection, removable.



Fig. 14 — repaired dentures

physicochemical propertiesthan those of traditional resins,provide the patients withremovable dentures suitable toour times, realized with themost modern techniques.

ConclusionsWe believe that the result ofour research is a turning pointin dental composite resindevelopment, for all the figuresof the sector (dental techniciansand dentists) and especially forthe patients. The systeminvolves applications for alltypes of dentures: removable,fixed (traditional and/orimplanted) and orthodontics.In fact, it is possible to replacePMMA materials in all thefields of dental sector in whichthey are employed. The imageswe show below are only sometypes of fixed dentures andorthodontics devices made withVLC resins, which complementthose regarding the removabledentures presented so far(Figs. 17-22).

Fig. 13 — broken dentures

Fig. 15 — mold for indirect relining Fig. 16 — dentures relined

The book Veneers by Attilio Sommella and Guerino Paolantoni introduces, thanks to beautifully depicted techno-clinical cases, the restoration of a single tooth or of more extensive rehabilitation cases. These restorations show the placement of one or more veneers with a high level of predictability that give the ambitious dental technician the ability to provide the aesthetic and functional needs that patients request.

To achieve success, when working with Veneers the techno-clinical team requires an extremely accurate execution that can be obtained thanks to a standardized system described in the book. By carefully

following the procedural algorithm outlined, the dental team will be able to perform minimally invasive restorations easily and free from risk.

Veneers – Mini-invasive Reconstructions

Hardcover: 240 pagesIllustrations: 1,336excellent quality of silk-screen printingPublication Date: 2014

Attilio Sommella & Guerino Paolantoni

$199+S&H

Knowledge is Power Get it for your dental library today

Mail orders to: Palmeri Publishing Inc.,35-145 Royal Crest Court, Markham, ON Canada L3R 9Z4

Phone Orders: 905. 489.1970 Fax Orders: 905. 489.1971 or order online at www.spectrumdialogue.com



Fig. 17 — All on four (R. Masci) Fig. 18 — Toronto bridge (M. Broglio)

Fig. 19 — temporary (B. Guida) Fig. 20 — Bite (F. Ferrara)

Fig. 21 — Disgiuntore (F. Rinaldin)

Fig. 22 — Expansion plate

Note: the devices made with VLC resins are repairable and can -be relined with the traditional PMMA-based resins as well.

Commodities noteThe lines of VLC products to which we refer here are: triAd®,rAdicA®, ecliPSe®, in JoY®. These products are manufactured anddistributed by DENTSPLY. ■Acknowledgements

We thank the following colleagues for collaborating with the development ofsystem TRE and for providing the photographic material: Raffaele Masci, BrunoGuida, Marco Broglio, Fabio Ferrara, Franco Rinaldin, Fabio Fantozzi.

About the authorMassimiliano Petrullo obtained his diploma in dental technology in1985. In 1992 he became the owner of a dental laboratory specializingin removable dentures. Since then he has been holding importantregional and national management positions in ANTLO. ANTLOtraining member and former SITET member.

As speaker, he frequently lectures in courses and conferences, nationallyand internationally, regarding the removable dentures and dentalcomposite resins, in all their application fields. He has authoredexquisite scientific publications in specialized journals. In 2006 hestarted an applied research on a new generation of extremelybiocompatible dental composite resins which he owns in exclusivemanner.

He has collaborated as technical and scientific consultant with differentkey companies of the sector; currently, he collaborates with the nationaland international divisions of DENTSPLY Corporate.

Massimiliano Petrullo – Owner of the dental laboratory.


SD-V14N4-April 15-Final_Layout 1 2015-04-02 12:32 PM Page 31


The hands-on course consisted of restoring four anterior teeth.The main challenge was highlighting the unique, light opticalpotential of Premium-Zirconium Oxide (Cercon ht, DeguDent) andevaluating the result in situ (Fig.1). During a side-by-side trainingcourse, the instructor working on the patient’s actual restorationencouraged the course participants to follow his technique step-by-step and apply it to their own work. Four crowns were milled out ofzirconium oxide (Cercon ht) followed by sandblasting and cleaning

Hans-Jürgen Joit,MDT

The Enormous Potentialof Premium-Zirconium Oxide

A rtistic aspects and skills play an important role in the field ofdental technology and have often been the reason fortechnicians to choose their profession. Anterior teeth

veneering clearly demands the combination of artistic competenceand technical skills. Teeth 1, 2 and 3 are the teeth predominantlynoticeable. They have a direct impact on a person’s famous “firstimpression”. Aesthetic aspects are therefore an important part ofdentistry.

Fig. 1 — Initial situation: Restoration required for four anteriorteeth in the maxilla

Fig. 2 — The four zirconium oxide (Cercon ht) crowns prior to firing

The design options of highly translucent zirconium oxide material combinedwith appropriate veneering ceramic are not utilized to their full potential bysome laboratories. In the following patient case Hans-Jürgen Joit, MDT guidesus step-by-step through his veneering technique with this versatile material.



Fig. 3 — The tricolor-layering technique: A technique that is knownall over the world in addition to the French speaking world.

Fig. 4 — Center areas are brightened with Flu 1 and OD 0

Fig. 5 — Defining the incisal curves is crucial in this phase Fig. 6 — Dentine D 2 and D 3 are applied using the alternatinglayering technique

Fig. 7 — Dentine A 1 adds beautiful light effects Fig. 8 — Enamel materials are used for lengthening and shaping

prior to firing (Fig. 2). For the veneering the participants chosespecial ceramic compounds (Cercon ceram love by DeguDent) thatperfectly matched the structure material. Introducing the tricolor-layering technique (Fig. 3) confirmed

that the correct structure material had been selected. Compared tousing opaque materials for the structure, the selected materialsenhanced the flow of light especially in the marginal areas. Coveringthese areas with a mixture of ID 3 and Sunset eliminated possiblegrey tones. The minimal layer thickness in those areas required the

application of a strong chroma and adding a little Flu 2 to themixture enhanced light flow in the marginal areas. Using opaquedentine ensured a harmonious light transition from the structureareas to the incisal edge.In compliance with the patient’s request and to ensure a natural

colour transition, the central areas were brightened with Flu 1 andOD 0 (Fig. 4). Defining the incisal curves was crucial in this phase,since it ensured adequate depth for the future enamel layer (Fig. 5). The cervical area required a strong application of A 2 dentine



Fig. 9 — Shaping and contouring are completed with variousenamel, transpa and opal compounds

Fig. 10 — Occlusal view of the applied layers prior to firing

while intense grey tones enhanced the incisal translucency. DentineD 2 and D 3 were applied using the alternating layering technique(Fig. 6). For the desired light effect in the center dentine A 1 wasselected (Fig. 7). Lengthening of the tooth shape was achieved byapplying alternate layers of enamel materials (E 2 and E 3) in theincisal area (Fig. 8). Internal effects like mamelons or secondarydentine were created with more opaque intensive dentines such asID 0 or ID 3. Shaping and contouring was completed with variousenamel, transpa and opal compounds (Fig. 9). When working onand refining incisal edges or curves and applying materials, one rule

applies: Accurate detail work on the teeth is crucial prior to firing(Fig. 10).

While the layering in the approximal regions was completed withenamel material, in the cervical areas the previously used mixturewas applied (Fig.11). Firing brought out the desired chameleon orcamouflage effect (Fig.12). Ideal colour coordination of the teethwith the surrounding areas was achieved by applying strong dentinein the marginal and approximal areas and adding light effects in thecenter while decreasing light intensity in the incisal direction. Thecrowns displayed certain brightness and matched their surroundings

Fig. 11 — Close-up of one of the crowns Fig. 12 — The famous chameleon-effect, here clearly visible

Fig. 13 — After corrective firing: Only the approximal contacts needsome refining

Fig. 14 — Harmonious transition from crown (position 22) to thenatural tooth (position 23)



harmoniously. Due to accurate preparation work only theapproximal contacts needed some refining (Fig.13).

Positioning the crown on 22 displayed a harmonious transitionfrom crown to natural tooth 23 (Fig.14). The approximal marginalline was visible from the mesial position and the actual tooth shapewas enhanced by the light effect on the labial surface. Afterconsulting with the patient, the instructor matched the crown’sbrightness to the existing restoration in the maxilla (Fig.15).

The course participants also achieved excellent results (Figs.16 to18) by adding their own styles and know-how to the concept, thusproving once more that dental restorations can be individual worksof art unless they were designed by a computer.

ConclusionRestorations made of Premium-Zirconium Oxide (Cercon ht,DeguDent) and matching veneering systems (Cercon ceram love,cercon ceram Kiss, DeguDent) offer a wide spectrum of designoptions. Using the correct technique ensures results of the highestaesthetic quality and completely satisfies the patient. Combiningtranslucent structure material with ceramic compounds is a majorpart of the success. This combination of materials producesrestorations with excellent light flow, harmonious colour transitionand depth. ■

Fig. 15 — The finished crowns in the patient’s mouth Fig. 16 — The crowns of the course participants …

Fig. 17 — …are equally impressive Fig. 18 — This article clearly provided a more individual look at theaesthetic side of dentistry



Everything aLaboratory Needs

Jay Black

Digital technology in the dental laboratory – today it's not so much a question ofwhether it is used, it's how well it supports our work as dental technicians.Sirona's inLab MC X5, a new milling and grinding machine for dental labs, setsnew standards for versatility of uses and materials.

JAY BLACK / It is exciting to be able to test a new machine asan inLab tester before the market launch. What can it do moreor better than the inLab MC XL, which we have used for five

years? How is it operated? What do the results look like? How easilycan it be integrated into the workflow? We were especially interestedin the last question. Our lab was one of the first to take part in theworld's largest dental network – Sirona Connect. This means that weare used to working with digital impressions. Now we were curiousabout what effect the new machine would have on the digitalprocess.

We received our inLab MC X5 last July. The first impression wasthat it is very compact, so it doesn't need much space and is very easyto use. But we were especially fascinated by the fact that the five-axismachine provides a great deal of product freedom. We can covermany more indications than before. With it, we can even producevery complex restorations that we used to have made in otherlaboratories. The machine mills various sizes of standard disks andblocks, thus allowing for a wide range of materials, and makingpossible the utilization of the best fabrication strategy.

Open for many thingsAn absolutely new feature of the inLab MC X5 is that it is open – itis completely irrelevant which system was used to generate the digitaldata of the impression and which program will be used to design the

restorations. The CAM software for the machine can easily use STLdata from any system, which is definitely not always the case.

Due to the many options for processing, the machine quicklyfound its place in our laboratory.

We use it for wet and dry processing and it is even possible tocombine the two methods seamlessly – depending on the materialused. Switching between wet and dry processing – for example, fromglass ceramic, wax, or PMMA to zirconium dioxide – is fast anduncomplicated. We use the inLab MC X5 for all our full zirconiawork and for zirconia frames, for temporary restorations and wax-ups, and for frames of various materials that are then veneered.

Tools used include carbide cutters and diamond grinders forprocessing standardized disks with a diameter of 98.5 millimetersand a height of up to 30 millimeters. Efficient utilization of materialis ensured by the disk management function and extensive nestingfunctions. The great advantage of the specially developed multi-blockholder is that up to six blocks of different materials can be put in itsimultaneously. This will soon also include dentin andmesostructure blocks.

Ideal complement to our machinesAs a laboratory that works with various machines from the inLabfamily, we were especially interested in seeing how the inLab MC X5would be integrated into our lab. We were pleased in seeing that it



fit in perfectly. It not only meets all demands of a productionmachine, it also complements Sirona's special laboratory programperfectly. When we need single crowns quickly, the inLab MC XLdoes a very good job. When we need larger numbers or morecomplicated restorations such as multi-unit bridges or telescopes, thestrengths of the inLab MC X5 come into play. It is therefore theideal standalone solution with everything the laboratory needs fordigital production. It can also be used optimally in combinationwith the inLab MC XL, and cleaning and servicing is not difficult.

I can definitely say that the inLab MC X5 does everything that Ias a dental technician need. It gives me the feeling that I will be wellprepared for the developments that are certain to come in digitalproduction of tooth restorations.

For me, the new inLab MC X5 sets a new standard. With it,Sirona clearly demonstrates that it understands dental technology

and has become a technology leader in this market. We can see thatSirona includes dental technicians and their needs in productdevelopment. ■

This article was published in issue 1/2015 of SIRONA VISION Magazine. Thearticle is copyrighted and may not be copied, distributed, modified, reused,reproduced or otherwise used without the permission of SIRONA.

The case study of an upper jaw severely abraded by bruxism shows how we use the machine in routine laboratory work. The patient wanted a zirconiumoxide bridge for the entire upper jaw. We received the digital impression data made with CEREC Omnicam via the Sirona Connect portal. The dentist sent usan image of the initial situation (left), for orientation. We loaded the data from the internet platform directly to the inLab software. The bite was opened by 1mm using the software's incisal pin tool (middle). The full-anatomy bridge was designed and a temporary restoration was milled from VITA CAD-Temp. We

used the period it was worn to verify the precision of bite and fit. Not until the patient was satisfied did we mill the final restoration from BruxZir solidzirconia milling blanks and sinter it in the inFire HTC speed sintering oven (right).

About the author Jay Black is a dental technician and graduate of the University ofFlorida (U.S.). Since 1997 he has been the manager of the WinterSprings Dental Lab in the city of 30,000 of the same name in Florida.As an inLab tester, he shares in the further development of the mostadvanced CAD/CAM systems in dental technology and passes hisexpertise on to his colleagues as an inLab trainer.

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a survival guideTrade shows:

Jonathan Parkinson shares his top tips for labs and technician exhibiting at a trade show

T rade shows are an important part ofthe dental industry and can be anexcellent way for laboratories to

network with dentists, develop existingrelationships and make new contacts.However, these events can be very expensiveto attend. A stand in itself is not cheap, andonce you factor in costs such as staffing,hotels and travel, this bill can often stretchinto many thousands of pounds.So, to help you get the most out of your

investment, here are my top 10 tips to makea success of your trade stand:

1. Never go alone Running a stand is a full-time job. However,you do need to take breaks and everyminute your stand is left unattended youare losing business. Even if you work onyour own, there is always someone you cantake along, even a family friend who can atleast engage customers in conversation andkeep them on the stand until you are back.

2. Dress appropriatelyExhibition halls often get very hot or verycold, so it’s important you are prepared forall eventualities. Also, you will be standingfor long periods of time, so make sure youwear comfortable shoes. You might want tothink about hiring or taking along a chair ifyou know that standing for long periods oftime will be difficult for you.

3. Get there in good timeThis may seem obvious, but arriving earlygives you plenty of time to familiariseyourself with the show; the facilitiesavailable and where you are in relation tothem. It can also be useful to look at otherexhibitors’ stands before the doors open.

4. Check your checklistIf you are saying ‘what checklist?" then

you’re making your first basic error. Don’tforget essentials such as: a record book /enquiry sheet, an invoicing book, notepadsand pens, sticky tape, extension cables, anda small first aid kit just in case. In general,larger shows will have a checklist you canuse and will offer support such as furnitureand lighting for hire.

5. Stand displayEveryone has their own ideas of what worksbest, but I strongly suggest you mock upyour stand back at the laboratory before yougo, so you discover any issues before youarrive at the show! If you intend to use acomputer, make sure you have thoughtabout your electricity supply and an internetconnection. Also remember to include a‘recess’ where you can keep coats and otherclutter out of the way. Fresh flowers canalways make a pleasant difference to a baretabletop or shelf

6. Make friends withneighboursIt is always useful to make friends with thepeople on neighbouring stands. Make sureyou help them as much as they help you - ifthey are not your direct competition thenthey may even be able to send extra businessyour way or even keep an eye on your standif you have had to attend alone!

7. Don't pounce, but don'tsit backFinding the right balance is difficult, butyou don’t want to be too pushy or too laidback. Make sure you smile and make eyecontact with passers-by Open with a goodneutral question that requires more thanjust a yes or no response. The worst thingyou can do is say, ‘Can I help you?’ Much

better to ask, ‘Are you in search of anythingparticular today?

8. Qualify your visitorsExhibitions attract a lot of auxiliary staff.Before you waste time engaging too much,qualify whether a visitor is someone whocan make a decision, and a decision in yourfield. Don’t be shy to ask!

9. Keep notesMost professional exhibitions are aboutfinding well-qualified prospects. Make notesand follow your goals. Find peopleinterested in the products you want to pushat the trade show and make sure you havecontact details to follow-up.

10. Prepare for thefollow-upThis is the most important part of any showDon’t just ring people up the next day - gothrough the notes you have made (point 9)and make sure you are well-read and readyto present a good confident pitch on thetopics they are interested in.■

About the author Jonathan Parkinson is a director and jointowner of Allport & Vincent DentalLaboratory along with his businesspartner Stephen Vincent. Based inOxfordshire, they operate a wholly privatefull-service laboratory with clients acrossthe country.

Jonathan joined the field of dentistrywith Nobel Biocare in the late ninetiesand has since worked globally in largecorporate laboratories and blue chipdental companies alike. He has a specialinterest in dental CAD/CAM, havingextensively consulted for one of the majordental companies in this area.


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Vol. 7, No. 2 – April 2015

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Each test page containing questions on two articles is worth 0.5 credit from the NBC. You must be a subscriber to be eligible to receive CE credits. Not a subscriber? Call905.489.1970 / 866.581.8949 or visit www.spectrumdialogue.com to subscribe online today! To get your Scientific CE credit for this article, correctly answer the

questions on the short test below. The answers can be found within the text of the article. Then, complete the form and submit it to Palmeri Publishing Inc. to receive yourcredit. It’s that easy! All tests are time sensitive and will expire one year following the issue date. You must complete all tests by this date in order to receive your credits.

TEST FOR NBC & RDT CREDITSFor the subscribers to dental labor international plus – Vol. 7 No. 3

Once you have completed the questionnaire, fill out the information below. You can photocopy this form. Then simply complete the form and submitto Spectrum dialogue online at www.spectrumdialogue.com or by fax to 905-489-1971. It’s that easy!

Subscriber Name: ___________________________________________________________ Phone #: ______________________________

Address: ___________________________________________________________________ Fax., #: ____________________________

Email: ___________________________________ CDT or RDT #: _______________________ Signature: __________________________

Questions for: The Power of Light

— Aldo Zilio

1. In his laboratory for his rehabilitations Aldo Zilio favours touse ...

a. acrylic materialsb. cement-retained prostheses covered in ceramicsc. acrylic materials with screw-retained prosthesesd. cement-retained prostheses

2. Which of these sentences is true?

a. Composites and resins can deteriorate very quickly.b. Ceramics have the risk of cracking and/or chipping.c. As an alternative to metal ceramic, new techniques are

recently using zirconia.d. All of the above

3. In one of the case studies, why was it necessary to increase theosseous volume in the upper frontal area?

a. So that implants able to support a 12-element arch could be inserted.

b. To compensate for the significant reabsorption and consequent alteration in the lip volume.

c. a and bd. To have a more pleasant aesthetic appearance.

4. According to the author of this article, he feels that thehuman factor - the dental technician's knowledge and abilityto plan is still the most important thing.

a. Trueb. False

5. Which of these sentences is false?

a. The pink parts were stratified using strictly one type of light colouring.

b. Four implants were applied using the All-in-four technique in the frontal area.

c. A fixed structure was made of highly translucent zirconia.d. The placing of glaze paste in the basal and interdental

spaces is indispensable.


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Questions for: Lingualized Occlusion— José Ma Fonollosa Pla

1. The author classifies dentures over implants into

a. One category of supportb: Two categories of supportc: Three categories of supportd: Four categories of supporte: Five categories of support

2. Lingualized occlusion can be classified as

a. Maximum buccal and lingual contacts in working occlusionb: No balancing contacts in lateral excursive movementc: Maxillary posterior teeth designed with no lingual cusp for

better non interfering lateral movementd: Maxillary lingual cusp contacts mandibular occlusal

surfaces in centric, working and balancinge: None of the above are true

3. With lingualized occlusion the vertical transmission of force isdirectly over the alveolar ridge

a. Trueb. False

4. The concepts of lingualized occlusion may be attributed to

a. Gysib: Hannahc: Gerberd: Payne and Pounde: B and C are correct

5. Gerber studies in occlusion recommend

a. Largest masticatory surface should be at the lowest point ofthe mandibular ridge

b: Stabilization included angled plains in the design of theposterior teeth

c: Set up included angulation of posterior teeth towards thepalate

d: Shortening of buccal cusps to reduce destabilizatione: All of the above are true


TEST FOR NBC & RDT CREDITSFor the subscribers to dental labor international plus – Vol. 7 No. 3

Each test page containing questions on two articles is worth 0.5 credit from the NBC. You must be a subscriber to be eligible to receive CE credits. Not a subscriber? Call905.489.1970 / 866.581.8949 or visit www.spectrumdialogue.com to subscribe online today! To get your Scientific CE credit for this article, correctly answer the

questions on the short test below. The answers can be found within the text of the article. Then, complete the form and submit it to Palmeri Publishing Inc. to receive yourcredit. It’s that easy! All tests are time sensitive and will expire one year following the issue date. You must complete all tests by this date in order to receive your credits.

Questions for: Applications of Removable Dentures

in Biocompatible Resins — Massimiliano Petrullo

1. Visible light cured resins can be used

a. In place in self or heat cured resinsb: For removable denturec: For fixed dentured: For orthodonticse: All of the above are true

2. The VLC resin technique described in this article wasdeveloped by

a. Ivoclarb: Dentsplyc: Myersond: Candulore: Yamohaci

3. VLC resin can be relined using conventional resin

a. Trueb. False

4. Some of the benefits of VLC resin are

a. Very high biocompatibility levelb: Can be relined both directly by the clinician or indirectly

by the labc: Can be repaired easilyd: Contain no monomerse: All of the above are true

5. VLC resins may be cured using

a. Conventional pressure pot and heatb: Immersing in boiling waterc: A self cure non monomer based coatingd: A light curing unite: All of the above are true

Questions for: The Enormous Potential of Premium-Zirconium Oxide

— Hans-Jürgen Joit

1. Zirconium Oxide material

a. should not be combined with any veneering ceramicb. can be combined with all veneering ceramicsc. should only be combined with appropriate

veneering ceramicsd. none of the above

2. Covering the marginal areas with a mixture of ID 3 and Sunset

a. increase the hueb. decrease the transparencyc. decrease Chromad. eliminated possible grey tones

3. Using opaque dentine

a. increased light transition from the structure to the incisalb. decreased light transition from the structure to the incisalc. diffused light transition from the structure to the incisald. none of the above

4. Firing

a. brought out the correct camouflage effectb. increased the light dentistry in the inscisal directionc. added colour coordinationd. all of the above

5. Excellent final results were achieved by

a. adding light effects to the restorationb. thanks to the know- how of the individual technicianc. using CAD softwared. all of the above


Once you have completed the questionnaire, fill out the information below. You can photocopy this form. Then simply complete the form and submitto Spectrum dialogue online at www.spectrumdialogue.com or by fax to 905-489-1971. It’s that easy!

Subscriber Name: ___________________________________________________________ Phone #: ______________________________

Address: ___________________________________________________________________ Fax., #: ____________________________

Email: ___________________________________ CDT or RDT #: _______________________ Signature: __________________________

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Documents

In This IssueLenny studied with the first graduating class of restorative dentists and surgeons in the Branemark system from the University of Toronto in 1984. Lenny is the owner of