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Fabrication of a maxillary implant-supported overdenture retained by two cemented bars: A clinical report
Fabrication of a maxillary implant-supported overdenture retained by two cemented bars: A clinical report Bulent Uludag, DDS, PhD,a Volkan Sahin, DDS, PhD,b and Gozde Celik, DDS, PhDc University of Ankara, Faculty of Dentistry, Ankara, Turkey Parallel placement of 2 separate bars may be indicated in patients where bone is available in the posterior part of the maxilla. Bars and stud attachments are the primary attachment systems compatible with the majority of the implant systems currently available; however, treatment planning in certain situations may be challenging due to the component available with the implant system used. This report describes the fabrication of a cemented bar design for use in situations when the components of the implant system are inadequate for fabrication of a screw-retained bar. (J Prosthet Dent 2007;97:249-51.)
D
ental implants improve prosthesis retention, stability, and occlusal function in some patients, such as those with acquired defects (trauma, malignant tumors) or congenital defects (cleft palate).1-3 If there is no plan for bone augmentation, bone grafting, or implant site development, the number of implants is limited to the number that can be placed in the available bone. If the number of implants is insufficient to support or retain the prosthesis entirely, an overdenture design is indicated, as it will gain some support, retention, or stability from the residual soft and hard tissues.4 Bars and stud attachments are the primary attachment systems compatible with the majority of the implant systems currently available.2 Parallel placement of 2 separate bars may be recommended in patients where more bone is available in the posterior part of the maxilla.5 Tissue defects may affect the desired position of implants. Holst et al6 reported on a removable implant-retained restoration for a maxillary tissue defect and stated that this treatment is preferable when discrepancies exist between the implant location and desired tooth position of the definitive restoration. Generally, patient responses to maxillary overdentures have been favorable, despite the level of maintenance care required.7,8 Significant improvements in comfort, mastication, speech, and appearance have been reported following this treatment modality.9 The primary advantage of this technique is lower cost when compared to maxillary fixed partial dentures (FPDs) after placement of additional implants or fabrication of a telescopic overdenture. Also, this design provided satisfactory outcomes with regard to retention and stability. The disadvantage of such a design may be a complication with the abutment-cement-bar interface. Decementation of the bar may occur. This article describes fabrication of a maxillary implant-supported overdenture retained by 2 bars cemented on milled
a
Professor, Department of Prosthodontics. Research Assistant, Department of Prosthodontics. c Research Assistant, Department of Prosthodontics. b
MAY 2007
implant abutments when the components of the implant system were inadequate for fabrication of a screwretained bar.
CLINICAL REPORT A 65-year-old white man previously treated with implants in a private dental office presented to the Department of Prosthodontics at Ankara University, School of Dentistry, for an implant-supported prosthesis. The patient reported receiving 4 implants in the maxilla and was referred to the School of Dentistry for prosthodontic treatment. The patient had a history of left maxillary cleft lip deformity and was treated with a maxillary complete denture opposing a mandibular removable partial denture (RPD). He complained of poor retention and instability of the dentures and sought implant treatment. Clinical examination revealed 2 remaining teeth, the mandibular right lateral incisor and canine. In addition, he had a bone defect in the left anterior premaxillary region (Fig. 1). There were 4 unrestored implants (SwissPlus; Zimmer Dental, Carlsbad, Calif) in sites of the maxillary right first premolar (4.8 mm in diameter with a 4.8-mm platform; length, 12 mm) and molar (3.7 mm in diameter with a 3.8-mm platform; length, 12 mm), and left second premolar and molar (3.7 mm in diameter with a 3.8-mm platform; length, 12 mm) (Fig. 2). Treatment options were presented, including fabrication of FPDs following placement of additional implants for both arches and telescopic retained overdentures, respectively, but these options were declined due to financial limitations. Thus, a treatment plan including a bar-retained maxillary implant-supported overdenture and a conventional mandibular RPD was presented and accepted by the patient. The RPD included a lingual plate major connector with I-bar and Y-bar direct retainers. Planning of the overdenture was challenging because neither ball abutments nor screwretained tapered abutments are available in the implant system (SwissPlus) with a platform diameter of 3.8 mm for fabrication of ball attachment or bar-retained THE JOURNAL OF PROSTHETIC DENTISTRY 249
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ULUDAG, SAHIN, AND CELIK
Fig. 1. Intraoral view before treatment.
Fig. 2. Pretreatment panoramic radiograph.
Fig. 3. Custom tray.
Fig. 4. Cast bars with mesial ball attachments.
Fig. 5. Intaglio view of definitive prosthesis.
Fig. 6. Intraoral view of definitive prosthesis.
overdentures. A decision was made to fabricate bars with mesial ball attachments cemented on milled implant abutments for both maxillary left and right quadrants separately.
Preliminary maxillary and mandibular impressions were made with irreversible hydrocolloid (Cavex CA 37; Cavex Holland BV, Haarlem, The Netherlands). A maxillary custom tray was prepared with autopolymerizing
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acrylic resin (Meliodent; Heraeus Kulzer, Hanau, Germany), leaving an open area in the implant region. Positive notches were prepared on the palatal side to retain the elastomeric impression material (Fig. 3). After removal of the cover screws, impression copings (SwissPlus) with appropriate diameters were placed. The impression of the alveolar mucosa was made with a zinc oxide eugenol impression paste (SS White Impression Paste; Prima Dental Group, Gloucester, UK) after border molding (Impression Compound; Kerr Italia SpA, Salerno, Italy). The tray was removed from the mouth, and excess impression material was removed. The tray was placed intraorally again. Light-bodied elastomeric impression material (Brecision; Bredent, Senden, Germany) was injected around the impression copings and supported with heavy-bodied elastomeric impression material (Brecision; Bredent), which was placed above the light-bodied material. A smooth transition between the impression materials was achieved. A mandibular impression was made with polyether impression material (Impregum F; 3M ESPE, St. Paul, Minn). Impression copings and implant replicas (Zimmer Dental) were inserted into the maxillary impression (Fig. 4). Impressions were poured with type IV stone (BEGO; Bremen, Germany). After obtaining horizontal and vertical maxillomandibular records with record bases and occlusion rims, the casts were transferred to a semi-adjustable articulator (Denar Advantage; Teledyne Waterpik, Ft Collins, Colo) using a face-bow transfer. Artificial teeth (Major; Major Prodotti Dentari, Torino, Italy) were selected and arranged on the record bases for a trial denture arrangement. The trial arrangement was evaluated intraorally for esthetics, phonetics, occlusal vertical dimension, and centric relation. A protrusive record was made to set the articulator’s condylar elements, and a balanced occlusal arrangement was achieved. Following the transfer of the positions of the maxillary and mandibular artificial teeth arrangement to the silicone index, implant abutments (Zimmer Dental) were milled with a milling unit (Paraskop M; BEGO). Maxillary round bars with 2 mesial attachments (Bredent) were cast with a base metal alloy (Biosil-F; Degussa, Hanau, Germany) (Fig. 4). Metal frameworks were cast with base metal alloy (Biosil F; Degussa). The maxillary and mandibular metal frameworks were evaluated intraorally. The teeth positioned in the silicone index were transferred to the cast. After an opaquer (Ropak Kompaktopaker UV; Bredent) was applied to the frameworks, the dentures were processed and finished (Fig. 5). Before insertion of the maxillary denture, bars were placed into the denture, and retentive clips were isolated with petroleum jelly (Vaseline; Unilever Inc., Englewood Cliffs, NJ). The milled implant abutments were screwed onto the implants, and the bar-denture assembly was cemented in place with autopolymerizing resin luting MAY 2007
THE JOURNAL OF PROSTHETIC DENTISTRY
cement (Nexus2 Universal Luting System; Kerr Corp, Orange, Calif). The maxillary denture was removed from the cemented bars after polymerization of the resin cement. Excess cement was removed and the dentures were inserted (Fig. 6). The patient was instructed in hygiene procedures associated with the dentures and the bars and scheduled for routine maintenance recalls. No complications occurred during the 12-month follow-up period.
SUMMARY Bars and stud attachments are the primary attachment systems compatible with the majority of the implant systems currently available; however, treatment planning in certain situations may be challenging due to the components available for the implant system used. This report describes treatment of a patient with a maxillary implant-supported overdenture retained by 2 bars cemented on milled implant abutments to overcome such a situation. REFERENCES 1. Lefkove MD, Matheny B, Silverstein L. Implant prosthodontic procedures for a completely edentulous patient with cleft palate. J Oral Implantol 1994;20:82-7. 2. Trakas T, Michalakis K, Kang K, Hirayama H. Attachment systems for implant retained overdentures: a literature review. Implant Dent 2006;15: 24-34. 3. Mericske-Stern R, Perren R, Raveh J. Life table analysis and clinical evaluation of oral implants supporting prostheses after resection of malignant tumors. Int J Oral Maxillofac Implants 1999;14:673-80. 4. Eckert SE, Carr AB. Implant-retained maxillary overdentures. Dent Clin North Am 2004;48:585-601. 5. Mericske-Stern RD, Taylor TD, Belser U. Management of the edentulous patient. Clin Oral Implants Res 2000;11(Suppl 1):108-25. 6. Holst S, Blatz MB, Bergler M, Wichmann M, Eitner S. Implant-supported prosthetic treatment in cases with hard- and soft-tissue defects. Quintessence Int 2005;36:671-8. 7. Smedberg JI, Lothigius E, Bodin I, Frykholm A, Nilner K. A clinical and radiological two-year follow-up study of maxillary overdentures on osseointegrated implants. Clin Oral Implants Res 1993;4:39-46. 8. Watson RM, Jemt T, Chai J, Harnett J, Heath MR, Hutton JE, et al. Prosthodontic treatment, patient response, and the need for maintenance of complete implant-supported overdentures: an appraisal of 5 years of prospective study. Int J Prosthodont 1997;10:345-54. 9. Chan MF, Howell RA, Cawood JI. Prosthetic rehabilitation of the atrophic maxilla using pre-implant surgery and endosseous implants. Br Dent J 1996;181:51-8. Reprint requests to: DR BULENT ULUDAG ANKARA UNIVERSITY FACULTY OF DENTISTRY DEPARTMENT OF PROSTHODONTICS PROTETIK DISTEDAVISI AB. D. 06500 BESEVLER ANKARA, TURKEY FAX: 90-312-2123954 E-MAIL: [email protected] 0022-3913/$32.00 Copyright Ó 2007 by The Editorial Council of The Journal of Prosthetic Dentistry.
doi:10.1016/j.prosdent.2007.03.005
251
D
ental implants improve prosthesis retention, stability, and occlusal function in some patients, such as those with acquired defects (trauma, malignant tumors) or congenital defects (cleft palate).1-3 If there is no plan for bone augmentation, bone grafting, or implant site development, the number of implants is limited to the number that can be placed in the available bone. If the number of implants is insufficient to support or retain the prosthesis entirely, an overdenture design is indicated, as it will gain some support, retention, or stability from the residual soft and hard tissues.4 Bars and stud attachments are the primary attachment systems compatible with the majority of the implant systems currently available.2 Parallel placement of 2 separate bars may be recommended in patients where more bone is available in the posterior part of the maxilla.5 Tissue defects may affect the desired position of implants. Holst et al6 reported on a removable implant-retained restoration for a maxillary tissue defect and stated that this treatment is preferable when discrepancies exist between the implant location and desired tooth position of the definitive restoration. Generally, patient responses to maxillary overdentures have been favorable, despite the level of maintenance care required.7,8 Significant improvements in comfort, mastication, speech, and appearance have been reported following this treatment modality.9 The primary advantage of this technique is lower cost when compared to maxillary fixed partial dentures (FPDs) after placement of additional implants or fabrication of a telescopic overdenture. Also, this design provided satisfactory outcomes with regard to retention and stability. The disadvantage of such a design may be a complication with the abutment-cement-bar interface. Decementation of the bar may occur. This article describes fabrication of a maxillary implant-supported overdenture retained by 2 bars cemented on milled
a
Professor, Department of Prosthodontics. Research Assistant, Department of Prosthodontics. c Research Assistant, Department of Prosthodontics. b
MAY 2007
implant abutments when the components of the implant system were inadequate for fabrication of a screwretained bar.
CLINICAL REPORT A 65-year-old white man previously treated with implants in a private dental office presented to the Department of Prosthodontics at Ankara University, School of Dentistry, for an implant-supported prosthesis. The patient reported receiving 4 implants in the maxilla and was referred to the School of Dentistry for prosthodontic treatment. The patient had a history of left maxillary cleft lip deformity and was treated with a maxillary complete denture opposing a mandibular removable partial denture (RPD). He complained of poor retention and instability of the dentures and sought implant treatment. Clinical examination revealed 2 remaining teeth, the mandibular right lateral incisor and canine. In addition, he had a bone defect in the left anterior premaxillary region (Fig. 1). There were 4 unrestored implants (SwissPlus; Zimmer Dental, Carlsbad, Calif) in sites of the maxillary right first premolar (4.8 mm in diameter with a 4.8-mm platform; length, 12 mm) and molar (3.7 mm in diameter with a 3.8-mm platform; length, 12 mm), and left second premolar and molar (3.7 mm in diameter with a 3.8-mm platform; length, 12 mm) (Fig. 2). Treatment options were presented, including fabrication of FPDs following placement of additional implants for both arches and telescopic retained overdentures, respectively, but these options were declined due to financial limitations. Thus, a treatment plan including a bar-retained maxillary implant-supported overdenture and a conventional mandibular RPD was presented and accepted by the patient. The RPD included a lingual plate major connector with I-bar and Y-bar direct retainers. Planning of the overdenture was challenging because neither ball abutments nor screwretained tapered abutments are available in the implant system (SwissPlus) with a platform diameter of 3.8 mm for fabrication of ball attachment or bar-retained THE JOURNAL OF PROSTHETIC DENTISTRY 249
THE JOURNAL OF PROSTHETIC DENTISTRY
ULUDAG, SAHIN, AND CELIK
Fig. 1. Intraoral view before treatment.
Fig. 2. Pretreatment panoramic radiograph.
Fig. 3. Custom tray.
Fig. 4. Cast bars with mesial ball attachments.
Fig. 5. Intaglio view of definitive prosthesis.
Fig. 6. Intraoral view of definitive prosthesis.
overdentures. A decision was made to fabricate bars with mesial ball attachments cemented on milled implant abutments for both maxillary left and right quadrants separately.
Preliminary maxillary and mandibular impressions were made with irreversible hydrocolloid (Cavex CA 37; Cavex Holland BV, Haarlem, The Netherlands). A maxillary custom tray was prepared with autopolymerizing
250
VOLUME 97 NUMBER 5
ULUDAG, SAHIN, AND CELIK
acrylic resin (Meliodent; Heraeus Kulzer, Hanau, Germany), leaving an open area in the implant region. Positive notches were prepared on the palatal side to retain the elastomeric impression material (Fig. 3). After removal of the cover screws, impression copings (SwissPlus) with appropriate diameters were placed. The impression of the alveolar mucosa was made with a zinc oxide eugenol impression paste (SS White Impression Paste; Prima Dental Group, Gloucester, UK) after border molding (Impression Compound; Kerr Italia SpA, Salerno, Italy). The tray was removed from the mouth, and excess impression material was removed. The tray was placed intraorally again. Light-bodied elastomeric impression material (Brecision; Bredent, Senden, Germany) was injected around the impression copings and supported with heavy-bodied elastomeric impression material (Brecision; Bredent), which was placed above the light-bodied material. A smooth transition between the impression materials was achieved. A mandibular impression was made with polyether impression material (Impregum F; 3M ESPE, St. Paul, Minn). Impression copings and implant replicas (Zimmer Dental) were inserted into the maxillary impression (Fig. 4). Impressions were poured with type IV stone (BEGO; Bremen, Germany). After obtaining horizontal and vertical maxillomandibular records with record bases and occlusion rims, the casts were transferred to a semi-adjustable articulator (Denar Advantage; Teledyne Waterpik, Ft Collins, Colo) using a face-bow transfer. Artificial teeth (Major; Major Prodotti Dentari, Torino, Italy) were selected and arranged on the record bases for a trial denture arrangement. The trial arrangement was evaluated intraorally for esthetics, phonetics, occlusal vertical dimension, and centric relation. A protrusive record was made to set the articulator’s condylar elements, and a balanced occlusal arrangement was achieved. Following the transfer of the positions of the maxillary and mandibular artificial teeth arrangement to the silicone index, implant abutments (Zimmer Dental) were milled with a milling unit (Paraskop M; BEGO). Maxillary round bars with 2 mesial attachments (Bredent) were cast with a base metal alloy (Biosil-F; Degussa, Hanau, Germany) (Fig. 4). Metal frameworks were cast with base metal alloy (Biosil F; Degussa). The maxillary and mandibular metal frameworks were evaluated intraorally. The teeth positioned in the silicone index were transferred to the cast. After an opaquer (Ropak Kompaktopaker UV; Bredent) was applied to the frameworks, the dentures were processed and finished (Fig. 5). Before insertion of the maxillary denture, bars were placed into the denture, and retentive clips were isolated with petroleum jelly (Vaseline; Unilever Inc., Englewood Cliffs, NJ). The milled implant abutments were screwed onto the implants, and the bar-denture assembly was cemented in place with autopolymerizing resin luting MAY 2007
THE JOURNAL OF PROSTHETIC DENTISTRY
cement (Nexus2 Universal Luting System; Kerr Corp, Orange, Calif). The maxillary denture was removed from the cemented bars after polymerization of the resin cement. Excess cement was removed and the dentures were inserted (Fig. 6). The patient was instructed in hygiene procedures associated with the dentures and the bars and scheduled for routine maintenance recalls. No complications occurred during the 12-month follow-up period.
SUMMARY Bars and stud attachments are the primary attachment systems compatible with the majority of the implant systems currently available; however, treatment planning in certain situations may be challenging due to the components available for the implant system used. This report describes treatment of a patient with a maxillary implant-supported overdenture retained by 2 bars cemented on milled implant abutments to overcome such a situation. REFERENCES 1. Lefkove MD, Matheny B, Silverstein L. Implant prosthodontic procedures for a completely edentulous patient with cleft palate. J Oral Implantol 1994;20:82-7. 2. Trakas T, Michalakis K, Kang K, Hirayama H. Attachment systems for implant retained overdentures: a literature review. Implant Dent 2006;15: 24-34. 3. Mericske-Stern R, Perren R, Raveh J. Life table analysis and clinical evaluation of oral implants supporting prostheses after resection of malignant tumors. Int J Oral Maxillofac Implants 1999;14:673-80. 4. Eckert SE, Carr AB. Implant-retained maxillary overdentures. Dent Clin North Am 2004;48:585-601. 5. Mericske-Stern RD, Taylor TD, Belser U. Management of the edentulous patient. Clin Oral Implants Res 2000;11(Suppl 1):108-25. 6. Holst S, Blatz MB, Bergler M, Wichmann M, Eitner S. Implant-supported prosthetic treatment in cases with hard- and soft-tissue defects. Quintessence Int 2005;36:671-8. 7. Smedberg JI, Lothigius E, Bodin I, Frykholm A, Nilner K. A clinical and radiological two-year follow-up study of maxillary overdentures on osseointegrated implants. Clin Oral Implants Res 1993;4:39-46. 8. Watson RM, Jemt T, Chai J, Harnett J, Heath MR, Hutton JE, et al. Prosthodontic treatment, patient response, and the need for maintenance of complete implant-supported overdentures: an appraisal of 5 years of prospective study. Int J Prosthodont 1997;10:345-54. 9. Chan MF, Howell RA, Cawood JI. Prosthetic rehabilitation of the atrophic maxilla using pre-implant surgery and endosseous implants. Br Dent J 1996;181:51-8. Reprint requests to: DR BULENT ULUDAG ANKARA UNIVERSITY FACULTY OF DENTISTRY DEPARTMENT OF PROSTHODONTICS PROTETIK DISTEDAVISI AB. D. 06500 BESEVLER ANKARA, TURKEY FAX: 90-312-2123954 E-MAIL: [email protected] 0022-3913/$32.00 Copyright Ó 2007 by The Editorial Council of The Journal of Prosthetic Dentistry.
doi:10.1016/j.prosdent.2007.03.005
251