*Sr. Lecturer**Professor***Professor,Dept. of Prosthodontics,Modern Dental College and Research Centre.Opp.Gandhinagar, Bijasan road, INDORE (M.P.) - 453112

NJDSR,Vol.1, January, 2012 37

Simple Overdenture Technique, Lasting Results-A Case Report*Rahul Shrivastava , **VaibhavAwinashe,***Rajeev Srivastava

INTRODUCTION

An Overdenture is a removable completeor partial denture that has one or moretooth roots to provide support. PreventiveProsthodontics emphasizes the importanceof any procedure that can delay oreliminate the future Prosthodonticproblems. The overdenture is a logicalmethod for the Dentist to use in preventiveProsthodontics. It is further emphasizedthat patient treated with overdenturesdemonstrate less vertical alveolar boneresorption in comparison to theconventional dentures and in turnpreserves the residual alveolar bone1,6

The success of overdentures is dependenton maintaining oral hygiene at an adequatelevel.2

DEFINITION

G P T 2008 -Any removable dentalprosthesis that covers and rest on one ormore remaining natural teeth, the roots ofnatural teeth and/or dental implants.

Heartwell

A tooth supported complete denture is adental prosthesis that replaces lost or

missing natural dentition and associatedstructures of the maxilla and/or mandibleand receives partial support and stabilityfrom one or more modified natural teeth.

RATIONALE OF OVERDENTURES

Rationale of an overdenture is to preservea portion of one of the major sensoryinputs i.e. input from the periodontalpropioceptors, which contain informationabout the magnitude and direction of theocclusal forces as well as about the sizeand consistency of the food bolus. Thisalong with the input of other receptors inthe mouth, muscles, TMJ contributes tothe overall response. The periodontalreceptors input are also protective againstocclusal overloading.

Advantages of overdenturesPreservation of alveolar ridge

Preservation of proprioceptive response

Ease of maintenance

Stability

Retention

Less trauma to the supporting tissues

ABSTRACT

“It is more important to preserve what already exists than to replace what is

missing” as stated by M.M.Devan. Progressive alveolar resoption after tooth removal can

be prevented by retaining teeth or tooth root beneath an overdenture. The tensile forces on

the periodontal ligament fibers may lead to deposition of bone which will provide better

stability, support and retention to the denture.

This clinical report describes use of selectively retained roots and abutments to minimize

alveolar ridge resorption below the complete dentures.

Key Words: Preservation of bone, bone resorption, proprioception, overdenture.

NJDSR,Vol.1, January, 2012 38

COPING OVERDENTURES:

Coping Types -A coping fitted to aprepared abutment is called a primarycoping. The sleeve or coping that fits overthis primary coping is referred to as asecondary coping.

There are four basic types of primarycopings:

1. Long Copings (6-8 millimetersfor vital teeth)

2. Medium Copings (4-6millimeters for vital and non-vital teeth)

3. Medium short copings (2-4mm for non-vital teeth)

4. Short Copings (1-2 millimetersfor non-vital teeth)

Overdenture with Attachments:

The attachments essentially increase thecrown-root ratio and then torque. Here,low caries index, proper home care,periodontal health and inter ridge distanceare absolutely necessary. Studies have alsoshowed that forces on Dolder bar producestress directed more apically than from theZest anchor.4

ATTACHMENTS CAN BECLASSIFIED ACCORDING TOSHAPE, DESIGN, AND PRIMARYAREA OF USE AS FOLLOWS: 3

Coronal1. Intracoronal attachments2. Extracoronal attachments

Radicular1. Telescope stud attachments (pressurebuttons)2. Bar attachments

a. Jointsb. Units

Accessory

1. Auxiliary attachmentsa. Screw unitsb. Pawl connectors

c. Boltsd. Stabilizers/balancerse. Interlocksf. Pins/screwsg. Rests

EVALUATION;

The examination includes: Patienthistory, Study casts, clinical examination,and Radiographs. It is very difficult tomake a correct diagnosis to determine ifthe overdenture is indicated for the patientor the problems can be solved byalternative techniques. This is ascertainedby taking a proper history of the patient’smedical background and past dentalhistory. The past dental history indicatesthe patients experience with previousremovable appliances and his attitudetowards the treatment. Study castsaccurately mounted on an articulator showthe occlusal relationship of the teeth andarches, the vertical spaces between archesand location of bony undercuts.

Radiographic examination is doneto evaluate presence of pathologicalconditions, presence of retained roots,bone loss, root curvatures, root canals arenoted.

Diagnosis includes: Clinical evaluationand selection of abutments, abutmentlocation, bone support, proximal spacebetween abutments, number of teethavailable, masticatory load and opposingdentition and the type/design of prosthesisrequired.

CLINICAL REPORT

A 67-year-old male patient reported withthe chief complaint of difficulty inchewing food.Patient gave history of loss of teeth sincefive years due to gum diseases.On extra-oral examination patient had aconvex profile. (Figure 1)

Fig 1: Pre-operative extra oral view

Intra-oral examination revealed remainingmandibular canines and premolars. Themaxillary residual ridge was favourablemandibular ridge was moderatelyresorbed. (Figure 2)

Fig 2: Intra Oral View of maxillary arch

After clinical and radiographic evaluationthe suggested treatment was to retain themandibular canines and premolars afterwhich an overdenture was planned. Thiswould increase the retention, stability andsupport of the prosthesis.

Procedure:

Informed consent was obtained from thepatient before starting the treatmentthe crown root ratio was not favourable

Fig 3: Cemented copings

NJDSR,Vol.1,

operative extra oral view

oral examination revealed remainingmandibular canines and premolars. The

y residual ridge was favourableandmandibular ridge was moderately

: Intra Oral View of maxillary arch

After clinical and radiographic evaluationthe suggested treatment was to retain themandibular canines and premolars after

was planned. Thiswould increase the retention, stability and

Informed consent was obtained from thet before starting the treatment since

the crown root ratio was not favourable

and was encroaching thespace in denture fabrication, the caninesand premolars were endodontically treated.Once the teeth were asymptomatic, teethwere reduced in size for more favourablecrown root ratio. Dome shape preparationwith chamfer finish line was done fthe teeth. Impressions were made (Figure3) and wax pattern was made with inlaycasting wax. (Figure 4)

Fig 3: Impressions

Fig 4: Wax pattern of copings

Once the metal copings were fabricated,they were polished and cemented usingGlass ionomer luting agent. (Figure

: Cemented copings Fig 5: Denture Placement

,Vol.1, January, 2012 39

and was encroaching the interocclusalspace in denture fabrication, the caninesand premolars were endodontically treated.Once the teeth were asymptomatic, teethwere reduced in size for more favourable

Dome shape preparationwith chamfer finish line was done for all

Impressions were made (Figurewax pattern was made with inlay

(Figure 4)

Fig 3: Impressions

Fig 4: Wax pattern of copings

Once the metal copings were fabricated,they were polished and cemented using

nomer luting agent. (Figure 5)

: Denture Placement

The impression techniques follow thesame principles and procedures that areused in constructing a conventionalcomplete denture.

Preliminary impressions were made andspecial trays fabricated.Border extensionswere checked and refined. Mandibularimpression was then made using mediumbody elastomeric impression material foreasy retrieval from the bony undercutbelow the mandibular canines (Figure 6Maxillary impression was made using zincoxide eugenol paste.

Fig 6: Secondary Impression

Occlusal rims were made and jaw relationsrecorded. Care was taken to achieveproper vertical dimension, as increasedvertical dimension could lead to alveolarresorption. Processing of the dentures wasdone followed by anterior and posterior tryin.

Dentures were placed in the patient mouthfollowed by laboratory remount andocclusal reshaping. (Figure

DISCUSSION

Progressive alveolar atrophy after toothextraction can be prevented by retainingteeth or tooth root beneath an overdenture.However patient cooperation is mandatoryfor maintaining adequate oral hygiene toavoid caries and periodontal disease of theretained teeth.The considerable reduction in crown rootratio and the dome shaped configuration oftooth abutment, along with carefuladjustment of contiguous denture basefacilitates an axial resolution of occlusalforces.

NJDSR,Vol.1,

The impression techniques follow thesame principles and procedures that areused in constructing a conventional

Preliminary impressions were made andspecial trays fabricated.Border extensionswere checked and refined. Mandibularimpression was then made using mediumbody elastomeric impression material foreasy retrieval from the bony undercut

the mandibular canines (Figure 6).Maxillary impression was made using zinc

Fig 6: Secondary Impression

Occlusal rims were made and jaw relationsrecorded. Care was taken to achieveproper vertical dimension, as increased

cal dimension could lead to alveolarProcessing of the dentures was

done followed by anterior and posterior try

Dentures were placed in the patient mouthfollowed by laboratory remount and

(Figure 7)

ve alveolar atrophy after toothextraction can be prevented by retainingteeth or tooth root beneath an overdenture.However patient cooperation is mandatoryfor maintaining adequate oral hygiene toavoid caries and periodontal disease of the

The considerable reduction in crown rootratio and the dome shaped configuration oftooth abutment, along with carefuladjustment of contiguous denture basefacilitates an axial resolution of occlusal

The tensile stimulation of periodontalfibers results in the deposition of bonefollowed by concomitant decrease inabutment mobility9. The support providedby the abutment teeth is in addition to thatsupplied by the residual ridges. Thestability is enhanced by the verticalcomponent of the retained tooth/root in thealveolar bone.

An additional feature is proprioceptionthrough the poverdentures gives a patient a sense ofdiscrimination to touch and pressure,which is less possible by usingconventional complete dentures.

In case of mandibular abutments, thetensile forces on the periodontal ligamentfibers may lead to deposition of bonewhich facilitated for better stability,support and retention of the lower denture.The only disadvantageprominent bone on the labial cortexcreated an undercut. Many times somecompromise had to be made by blockingout the undercut resulting in denture flangethat is spaced away from tissues.

Conclusion:

Overdenture supported by natural teeth isone of the best treatments available foredentulous condition. Despite recentdevelopment in dental implantology, theconservative approach of root preservationis still valid. Greater emphasis must begiven on proper case selection, diagnosis,and treatment planning.

By preserving the submerged root or teethfor overdenture, alveolar bone resoptioncan be reduced considerablyAlso there will be drastic improvement inretention, stability and support of theprosthesis.Overdentures thus become an alternativetreatment for patients advised for totalextraction.

Proper oral hygiene instruction must begiven to the patient and reinforcement ofthe same done. Recall examinations with

,Vol.1, January, 2012 40

The tensile stimulation of periodontalrs results in the deposition of bone

followed by concomitant decrease in. The support provided

by the abutment teeth is in addition to thatsupplied by the residual ridges. Thestability is enhanced by the verticalcomponent of the retained tooth/root in the

An additional feature is proprioceptionthrough the periodontal fibers,overdentures gives a patient a sense ofdiscrimination to touch and pressure,which is less possible by usingconventional complete dentures.

In case of mandibular abutments, thetensile forces on the periodontal ligament

d to deposition of bonewhich facilitated for better stability,support and retention of the lower denture.The only disadvantage5 was that theprominent bone on the labial cortexcreated an undercut. Many times somecompromise had to be made by blockingut the undercut resulting in denture flange

that is spaced away from tissues.

Overdenture supported by natural teeth isone of the best treatments available foredentulous condition. Despite recentdevelopment in dental implantology, the

rvative approach of root preservationis still valid. Greater emphasis must begiven on proper case selection, diagnosis,and treatment planning.

By preserving the submerged root or teethfor overdenture, alveolar bone resoptioncan be reduced considerably.Also there will be drastic improvement inretention, stability and support of the

Overdentures thus become an alternativetreatment for patients advised for total

Proper oral hygiene instruction must begiven to the patient and reinforcement ofthe same done. Recall examinations with

NJDSR,Vol.1, January, 2012 41

radiographs at regular intervals of sixmonths or less will maintain the prosthetic,restorative and periodontal status of thepatient at acceptable levels, which in turnleads to the success of the overdentures.

References

1. Crum RJ, Rooney GE Jr: Alveolar boneloss in overdentures: A 5-year study. JProsthet Dent 1978;40:610-613.

2. Ettinger RL, Taylor TD, Scandrett FR:Treatment needs of overdenture patients ina longitudinal study: Five-year results. JProsthet Dent 1984;52:532-537.

3. Mensor MC Jr: Attachment fixation ofthe overdenture: Part II. J Prosthet Dent1978;39:16-20.

4. Thayer HH, Caputo AA: Effects ofoverdentures upon the remaining oralstructures. J Prosthet Dent 1977;37:374-381.

5. Winkler .S . Essentials of completedenture Prosthodontics, secondedition,2000, 384-402.

6. Millar PA.: complete denture supportedby natural teeth. J Prosthet Dent1958;8:924.

7. Zarb GA et al, Overdentures, In;Prosthodontic Treatment for edentulouspatients, 12th edition, 2004, St Louis, C VMosby Publishers, pp. 160-176.

8. DeFranco RL. Overdentures, In:Essentials of complete dentureprosthodontics, 2nd edition, 2009, India,AITBS Publishers, pp. 384-402.

9. Heartwell. Jr, C.M. and Rahn, A.O.:Syllabus of complete denture, 4th edition,Philadelphia, Lea and Febiger, 1986, Page499-520.

Address for Correspondence:

Dr. Rahul ShrivastavaSr. lecturer, Dept. of Prosthodontics,Modern Dental College and Research Centre,Indore. (M.P)drrahulshri@gmail.comMobile: 94253-52603