PubMed Health⌕ Search

Biomedical subjects

Roger M Watson

Publications and source records attributed to Roger M Watson.

4 recordsLinked to original sources
PubMed2004

Single tooth crowns supported on hydroxyapatite coated endosseous dental implants: a prospective 5-year study on twenty subjects.

AIM: To evaluate the success and maintenance requirements of cylindrical, hydroxyapatite coated implants used as single-tooth implants. DESIGN: A five-year prospective trial. METHOD: Twenty patients, attending the Department of Prosthetic Dentistry at GKT Dental Institute, London, were provided with 23 Calcitek, Integral Omniloc single tooth implants. Annual reviews were undertaken for five years. Assessment criteria included implant survival; abutment or crown looseness; radiographic evidence of bone loss; evidence of plaque and inflammation of the mucosal cuff; the patient's perception of the restoration. RESULTS: All implants integrated. Two subjects, with three crowns, dropped out giving a known cumulative survival rate of 87%. Twelve implants exhibited no measurable bone loss and six demonstrated funnel formation up to 2mm in depth which, at five years, appeared to be stable; three implants exhibited continuing bone loss and their inclusion as failures gives a known success rate of 74%. The abutments came loose on four occasions; the crowns decemented on 12 occasions; two crowns were repaired and one remade. The appearance was judged to be good or very good. CONCLUSION: The prospective study indicated that hydroxyapatite coated implants can be successful as single tooth implants, over a five-year period.

Adolescent↗
PubMed2002

The effects of fixed and removable implant-stabilised prostheses on posterior mandibular residual ridge resorption.

This study investigated the change over time in the area of the posterior mandibular residual ridge in patients wearing either i) mandibular overdentures stabilised by two implants (Brånemark System; Nobel Biocare, Göteborg, Sweden) connected by a bar, or ii) mandibular fixed cantilever prostheses stabilised on five or six implants. Proportional measurements were made in order to compare the area of the residual ridge with an area of bone uninfluenced by resorption. Measurements were made by digitising tracings of panoramic radiographs that were taken shortly after implant insertion and up to seven years later. With the use of overdentures, the posterior bone area index reduced by a mean of 1.1% per annum, while a mean bone area index increase of 1.6% per annum was demonstrated in association with fixed prostheses. A multiple linear regression model was fitted to predict the change in posterior area from type of prosthesis, gender, age, years of edentulism and initial height of the mandible. The model was only significant for initial height of mandible (P = 0.04) and type of prosthesis (P = 0.0001). In conclusion, patients rehabilitated with implant-stabilised mandibular overdentures demonstrated low rates of posterior mandibular residual ridge resorption, while patients rehabilitated with implant-stabilised mandibular fixed cantilever prostheses demonstrated bone apposition in the same area.

Adult↗
PubMedDate not supplied

Maintenance requirements of implant-supported fixed prostheses opposed by implant-supported fixed prostheses, natural teeth, or complete dentures: a 5-year retrospective study.

PURPOSE: The purpose of this study was to compare the maintenance requirements of implant-supported fixed prostheses with cantilever arms in edentulous jaws when opposed by fixed prostheses of similar design, by natural teeth, or by complete dentures. MATERIALS AND METHODS: The maintenance requirements for the 5-year follow-up period were obtained by examining the dental records of 37 people. Six were provided with fixed prostheses in both arches, 22 with a fixed prosthesis in the mandible opposed by a complete denture, and 9 with a fixed prosthesis opposed by natural teeth. Everyone was treated with Nobel Biocare implants using standard implant and prosthetic protocols. RESULTS: The denture teeth and acrylic resin were repaired on 44 occasions in the group with implants in both jaws, on 14 occasions in the group with implants opposed by natural teeth, and twice in the group in which the implants were opposed by a complete denture. The group with implants in both jaws was more likely to fracture the gold-alloy framework, which occurred on six occasions. The group with implants in both jaws was significantly different from the other two groups in relation to higher incidence of fracture of the teeth and gold-alloy framework. CONCLUSION: The maintenance requirements of implant-supported fixed prostheses with cantilever arms opposed by fixed prostheses of similar design were much greater than when opposed by natural teeth or complete dentures.

Acrylic Resins↗