Rehabilitation of a Completely Edentulous Patient with a Mandibular Overdenture

International Journal of Oral Implantology and Clinical Research, May-August 2015;6(2):53-57 53

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Rehabilitation of a Completely Edentulous Patient with a Mandibular Overdenture-supported by two Immediately Loaded Single Piece Implants1Kartik Kapoor, 2K Harshakumar, 3S Lylajam, 4R Ravichandran

ABSTRACTFor completely edentulous mandible, the rehabilitation modality of an implant retained overdenture on two implants placed in anterior mandible is a simple, acceptable and predictable treatment option. It contributes significantly to patients psycho­logical and social well­being. Increased retention results in greater patient satisfaction than conventional removable complete denture. This case report describes the use of two single piece implants with ball attachments to retain an implant retained mandibular overdenture in order to rehabilitate a completely edentulous male patient. It also illustrates the approach of prosthetically driven implant placement.

Keywords: Dental implant, Immediate dental implant loading, Implant­supported denture, Overdenture.

How to cite this article: Kapoor K, Harshakumar K, Lylajam S, Ravichandran R. Rehabilitation of a Completely Edentulous Patient with a Mandibular Overdenture­supported by two Immediately Loaded Single Piece Implants. Int J Oral Implantol Clin Res 2015;6(2):53­57.

Source of support: Nil

Conflict of interest: None

InTRoduCTIon

Edentulism continues to have a high prevalence amongst the elderly and is a common clinical entity. The most common treatment modality for the completely edentu­lous jaw is conventional removable complete dentures. However, it involves some functional shortcomings and psychosocial limitations.1 Since the introduction of osseo­integrated implants the provision of a stable, complete prosthesis for edentulous patients has become routine, predictable and efficacious.2 Titanium dental implants especially in the anterior mandible have a very high success rate due to which just two implants and ball attachments is preferred for retention of an overdenture, instead of four implants and a bar.3 Van Steenberghe et al

case report

1Senior Resident, 2Professor and Head, 3,4Professor1-4Department of Prosthodontics, Government Dental College Thiruvananthapuram, Kerala, India

Corresponding Author: Kartik Kapoor, Senior Resident Department of Prosthodontics, Government Dental College Thiruvananthapuram, Kerala, India, e-mail: drkartik26@gmail.com

10.5005/jp-journals-10012-1136

were among the first authors to propose placement of only two implants in the edentulous mandible.4

According to McGill consensus statement on overden-tures, evidence suggests that a two-implant overdenture should become the standard care for treatment of the edentulous mandible.5 Researchers have demonstrated that osseointegration can be achieved with early or immediate loading protocols if micromotion is contained within the suggested limits.1 Takanashi et al estimated that the time required to fabricate a mandibular over-denture retained by implants with ball attachments was not significantly different than the time needed for conventional denture treatment.6 This article presents a case report where a completely edentulous patient is rehabilitated with a maxillary conventional complete denture and an immediately loaded mandibular implant supported overdenture on two single piece implants with ball attachments and O-ring incorporated housings.

CaSE REPORt

A 50-year-old male patient presented with a chief complaint of missing teeth and desired a replacement for the same. Dental history revealed that patient has lost his teeth 2 years back and has been completely edentulous since then. Medical history was non-contributory. The patient was well built and had a coordinated gait. Upon intraoral examination, it was found out that the patient was completely edentulous with well formed maxillary and mandibular ridges without any bony undercuts. Adequate amount of keratinized tissue was also present. Upon discussion with the patient, the treatment option of maxillary conventional removable complete denture and mandibular implant supported overdenture was planned. Panoramic radiographic examination revealed that mandibular residual alveolar ridge was having good bone quality and quantity (Fig. 1). Two single piece implants of 11 mm length and 3.3 mm diameter with ball abutments (Myriad-Snap, Equinox) were planned to be placed at the bilateral canine premolar region using a single stage surgical protocol.

Primary and secondary impressions were made, tentative maxillomandibular relations were recorded, maxillary cast was mounted on a Hanau Wide Vue

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articulator using a facebow transfer (Fig. 2). Mandibular cast was mounted using a centric relation record. Gothic arch tracing was done to verify the centric relation and interocclusal records were made using bite registration paste (Coltène/Whaledent JET BLUE). Teeth were arranged in bilateral balanced occlusion, Try-in was done (Fig. 3) and patient’s consent was obtained. The trial denture was then duplicated in heat cure clear acrylic (Lucitone Clear, Dentsply) to be used as a surgical guide for implant placement (Fig. 4). Trial dentures were processed, finished and polished in the conventional manner. The duplicated denture is mounted on an implant surveyor

and osteotomy sites were marked and prepared after planning optimum parallelism (Fig. 5). Two stainless steel balls were placed into the prepared sites and an orthopantomogram (OPG) was taken to confirm the position and location of mental foramen.

The final dentures were checked in patient’s mouth to confirm a bilateral balanced occlusion. On the day of surgery, after administering local anesthesia (2% lignocaine hydrochloride with epinephrine 1:2,00,000) a flapless approach was employed as good amount of keratinized mucosa was present. After placing the surgical guide in the planned position on the ridge initial access for the osteotomy was made using the D 2.0 mm pilot drill and sequentially enlarged to D 3.3 mm with a speed of 1000 RPM. To achieve parallelism Guidepin was placed in the first osteotomy site and the second osteotomy site was prepared on the contralateral side. The two implants were then placed in the prepared osteotomy sites using a torque ratchet and primary stability of 30 Ncm was achieved on both the implants (Fig. 6).

Since the primary stability was sufficient for imme-diately loading, the prosthetic phase was initiated in the same appointment. The fit of the plastic transfer caps

Fig. 1: Preoperative orthopantomograph

Fig. 2: Facebow transfer Fig. 3: Try-in

Fig. 4: Surgical guide Fig. 5: Determination of osteotomy site and implant angulation

Rehabilitation of a Completely Edentulous Patient with a Mandibular Overdenture

International Journal of Oral Implantology and Clinical Research, May-August 2015;6(2):53-57 55

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were applied around the neck of the laboratory analogs and cast was poured in type IV die stone (Elite Master, Zermack) to obtain a working model (Fig. 9). The female housings with the O-ring matrices were snapped into place on the laboratory analogs on the working model. Adequate block out below the housing was also done using latex. The final mandibular denture was relieved from inside to create space for housing (Fig. 10) and a pick-up was made onto the cast using autopolymerizing acrylic resin, hence preventing surgical site from exposure to the acrylic monomer (Fig. 11).

The denture was inserted and checked for retention and occlusion (Fig. 12). Postoperative instructions were given, including rinsing the mouth with 0.12% chlor-hexidine gluconate three times per day. Furthermore, antibiotics and analgesics in appropriate doses were pre-scribed. Patient has instructed not to remove denture for next 48 hours. Two days later, he was reviewed where the healing was found to be uneventful. The prosthesis was functionally effective and esthetically pleasing (Figs 13 and 14).

Fig. 10: Denture relieved to provide space for retentive components

Fig. 6: Single piece implants with ball abutments in situ

Fig. 7: Transfer caps snapped on the ball abutments Fig. 8: Pick-up impression using surgical guide

Fig. 9: Completed Master cast with implant analogs

over the ball head and onto the prosthetic platform were verified (Fig. 7). The surgical guide was relieved to accom-modate the transfer caps and the caps were picked up by a double mix impression technique using polyvinyl silox-ane impression material (Aquasil LV, Dentsply) (Fig. 8). The laboratory analogs were positioned, soft tissue masks

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DISCuSSIOn

One of the most important objectives of dental implan- tology is to improve retention of mandibular complete dentures, which are often encountered with problems in jaw bone with advanced ridge resorption.7,8 It is also imperative to realize that the conventional complete denture, the two-implant overdenture, multiple-implant splinted or unsplinted overdentures, and fixed implant prostheses are all currently accepted standard-of-care treatments for the edentulous mandible. The McGill consensus statement does not preclude more sophisticated treatments like bar overdentures or fixed prostheses, but merely states two-implant unsplinted overdentures ‘as a minimal treatment objective.5 Although relatively high number of implants may give the prostheses some reliability, the success rate of two or three implants in the anterior mandible for overdenture retention has proved successful.9

A 95.6% success rate was observed by Cooper et al in their research of two microthreaded immediately loaded screw implants to retain a mandibular overdenture, with ball attachments.10 The literature is inconclusive as survival rates may not only depend on the loading pro-tocol, but also on the number of implants, the attachment

Fig. 11: Intaglio surface of maxillary complete denture and mandibular overdenture

Fig. 12: Final esthetic result

Fig. 13: Post insertion extraoral view

system, or the implant surface.1,11 Though the support is derived from both the implants as well as the anato mical primary stress bearing areas, the use of wide variety of attachment systems, including bar, magnets and stud attachments, has also proven both clinically predictable and effective. Studies conclude that failure to achieve ideal implant parallelism will result in higher mainte-nance needs for the unsplinted overdenture patient and would also generate deleterious forces on implant head. Therefore, implant parallelism is of paramount impor-tance from a prosthetic and aftercare perspective.12

The O-ring is used to enhance retention of implant retained overdenture prostheses. They have a number of advantages, including ease of use, maintenance, low cost, and elimination of a superstructure bar. Few shortcomings are that O-rings wear over time, gradually lose retention, and must be replaced periodically. It is also essential that O-ring abutments be parallel to each other.13 Prior to implant surgery, the clinician must first determine final tooth position and overdenture form and transfer this information to a surgical guide. Implant placement should be dictated by a balance between final tooth position via surgical guide and available bone, considered three dimensionally.4 In the current case

Fig. 14: Postoperative orthopantomograph

Rehabilitation of a Completely Edentulous Patient with a Mandibular Overdenture

International Journal of Oral Implantology and Clinical Research, May-August 2015;6(2):53-57 57

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report, the denture was fabricated prior to surgical phase and hence the implant placement was prosthetically driven. It is also vital to avoid lingual perforation dur-ing implant placement. Hemorrhage of the floor of the mouth is a potentially serious complication. A simple, uncomplicated one-stage surgical protocol is considered the technique of choice with implants as parallel as possi- ble to each other with the endpoint being supracrestal placement.4,14 As the chairside pick-up technique using autopolymerizing resin can cause monomer exposure to surgical site in immediately loaded cases, in the present case report a quick laboratory method is described where the pick-up is made using the same surgical guide and a working model is produced for final pick-up of housings.

COnCLuSIOn

Implant retained overdentures have emerged as a func-tionally superior treatment modality than the conven-tional removable dentures, also it has proven its worth as a cost effective and less invasive option to fixed implant dental prostheses. This article presents a case where a edentulous male patient is rehabilitated by a maxillary removable complete denture and an immediately loaded mandibular implant supported overdenture on two single piece implants with ball attachments and O-ring incorporated housings. The implants were prosthetically driven as the denture fabrication was prior to implant surgery. Also, a quick laboratory pick-up impression technique is described with the help of an already made surgical guide. Since the surgical technique was a single stage flapless procedure, the healing was uneventful and fast. During follow-up, the patient was found to be happy and content as retention and esthetics were satisfactory.

REfEREnCES

1. Schimmel M, Srinivasan M, Herrmann FR, Müller F. Loading protocols for implant-supported overdentures in the eden-tulous jaw: a systematic review and meta-analysis. Int J Oral Maxillofac Imp 2013;29:271-286.

2. Adell R, Eriksson B, Lekholm U, Brånemark PI, Jemt T. A long-term follow-up of tissue integrated implants in the treatment of the totally edentulous jaw. Int J Oral Maxillofac Imp 1990;5(4):347-359.

3. Klemetti E, Chehad A, Takanashi Y, Feine JS. Two-implant mandibular overdentures: simple to fabricate and easy to wear. J Can Dent Assoc 2003;69(1):29-33.

4. Van Steenberghe D, Quirynen M, Calberson L, Demanet M. A prospective evaluation of the fate of 697 consecutive intra-oral fixtures ad modum Branemark in the rehabilitation of edentulism. J Head Neck Pathol 1987;6:53-58.

5. Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Wismeijer D. The McGill consensus statement on overdentures. Montreal, Quebec, Canada. May 24-25, 2002. Int J Prosthodont 2002;15(4):413-414.

6. Takanashi Y, Penrod JR, Chehade A, Klemetti E, Savard A, Lund JP, et al. Does a prosthodontist spend more time providing mandibular two-implant overdentures than conventional dentures? Int J Prosthodont 2002;15(4):397-403.

7. Zarb GA, Schmitt A. The longitudinal clinical effectiveness of osseointegrated implants: the Toronto study. Part II—the prosthetic results. J Prosthet Dent 1990;64(1):53-61.

8. Zarb GA, Schmitt A. The longitudinal clinical effectiveness of osseointegrated implants: the Toronto study. Part III—problems and complications encountered. J Prosthet Dent 1990;64(2):185-194.

9. Mericske-Stern R, Zarb GA. Overdentures: an alternative implants methodology for edentulous patients. Int J Prosthodont 1993;6(2):203-208.

10. Cooper LF, Scurria MS, Lang LA, Guckes AD. Treatment of edentulism using Astra Tech implants and ball attachments to retain mandibular overdentures. Int J Oral Maxillofac Imp 1999;14(5):646-653.

11. Sadowsky SJ. The implant supported prosthesis for the edentulous arch: design considerations. J Prosthet Dent 1997; 78(1):28-33.

12. Mericske-Stern R. Overdentures with roots or implants for elderly patients: a comparison. J Prosthet Dent 1994;72(5): 543-550.

13. Winkler S, Piermatti J, Rothman A, Siamos G. An overview of the O-ring implant overdenture attachment: clinical reports. J Oral Imp 2002;28(2):82-86.

14. Brånemark PI, Zarb GA, Albrektsson T. Tissue-integrated prostheses: osseointegration in clinical dentistry. Plas Recon Surg 1986;77(3):496-497.