Zirconia abutments for single-tooth implant restorations: a 10- to 11-year follow-up study.

OBJECTIVES: To evaluate the clinical outcome of custom-made zirconia abutments for implant-supported single-tooth restorations 10-11 years after insertion. MATERIAL AND METHODS: The study comprises a clinical examination of 23 patients with 30 restorations placed 10-11 years ago. Oral surgeons placed the implants. The prosthodontic treatment was provided at a prosthodontic specialist clinic. The restoration was either an all-ceramic crown for cementation or a screw-retained one-piece restoration with the veneering porcelain baked directly to the zirconia abutment. Besides the clinical and radiographic examination at the 10- to 11-year follow-up, the patients' records were scrutinized regarding clinical and radiographic data from insertion of the restoration up to the last visit at the clinic. RESULTS: The zirconia abutments performed well. Both technical and biological complications were rare; most patients were in general extremely satisfied with the restorations. No all-ceramic crowns fractured during the observation period. One implant was lost after 5½ years in service. There were no significant differences for changes in any of the soft tissue registrations or the peri-implant marginal bone level between the conventional two-piece abutment-crown restoration and the one-piece restoration. The peri-implant bone level changes from placement to the clinical examination 10-11 years later were small (mean 0.26 mm, SD 0.6 mm). CONCLUSIONS: Zirconia abutments for single-implant crowns demonstrated excellent technical and biological results over 10-11 years of function, and most patients were extremely satisfied with the aesthetics and the function of their single-implant restorations.

Zirconia abutments for single-tooth implant restorations: a retrospective and clinical follow-up study.

OBJECTIVE: To evaluate the clinical outcome of custom-made zirconia abutments for implant-supported single-tooth restorations up to 5 years after insertion. MATERIAL AND METHODS: The study comprises two parts: (Part 1) retrospective evaluation of records of 130 patients treated with 185 single-tooth implant restorations using zirconia abutments; (Part 2) clinical examination of 25 patients with 40 restorations placed >3 years ago. Oral surgeons placed the implants. The prosthodontic treatment was provided at a prosthodontic specialist clinic. The restoration was either an all-ceramic crown for cementation or a screw-retained one-piece restoration with the veneering porcelain baked directly to the zirconia abutment. Registration of all patients' records comprised clinical and radiographic data from insertion of the restoration up to the last visit at the clinic. RESULTS: Parts 1 and 2: The zirconia abutments performed well over the follow-up period. The rates of both technical and biological complications were low, and the patients were in general extremely satisfied with the restorations. No all-ceramic crowns fractured during the observation period. Two abutments (1%) fractured, one at insertion, the other after 2 months. Part 2: There were no significant differences for changes in any of the soft tissue registrations or the peri-implant marginal bone level between the conventional two-piece abutment-crown restoration and the one-piece restoration. The peri-implant bone level changes from placement to the clinical examination 3-5 years later were small (mean 0.29 mm, SD 0.87 mm). CONCLUSION: Zirconia abutments for single-implant crowns seem to demonstrate good short-term technical and biological results.

Long-term function of single-implant restorations: a 17- to 19-year follow-up study on implant infraposition related to the shape of the face and patients' satisfaction.

BACKGROUND: Various levels of infraposition of single-implant restorations have been observed in long-term follow-up studies, but little knowledge is available on the biological mechanism behind this pattern. PURPOSE: The primary aim of this study is to report the frequency and severeness of implant infraposition in the anterior single-implant application after 17 to 19 years in function and, secondly, to try to relate these observations to anatomical appearance of the shape of the face of the patient. MATERIALS AND METHODS: The present study comprised of 57 patients who were provided with 65 CeraOne™ single-tooth restorations (Nobel Biocare AB, Gothenburg, Sweden) between 1989 and 1991. Altogether 46 of these patients were treated with single implants in the anterior region. Besides clinical and radiographic data, clinical photographs, study casts, and patient's assessment of the long-term aesthetic result (visual analog scale) was collected at the termination of the present study. The degree of implant crown infraposition was related to assessed facial shape and to patient and clinical assessment of the aesthetic result by means of Pearson's correlation test. To increase the numbers of patients, another group of 25 patients presented in another similar study were pooled with the present material for prevalence calculations. RESULTS: Altogether 47 patients showed up for the final examination after an average of 18 years (82%). Two implants failed (18 years cumulative survival rates [CSR]- 96.8%) and eight original single-crown restorations were replaced (CSR 83.8%). Three of the replaced crowns were replaced because of infraposition of the crowns. About 40% of the patients showed signs of infraposition, similar in younger and older age groups, but more frequently observed in female patients at termination of the study (p < 0.05). There was a weak trend indicating an association between "long-face" appearance and infraposition of the crown restoration (p > 0.05), and patients were more satisfied with the aesthetic clinical result than the participating clinicians (p < 0.05). CONCLUSION: Single-implant restorations in the anterior upper jaw may present small degrees of infraposition in long-term perspectives. Female patients seem to be at a higher risk of infraposition (p < 0.05), but no clear relationship between age at implant placement or facial shape and degree of infraposition was possible to establish (p > 0.05). Patients were more satisfied with the aesthetic result, as compared with the clinicians (p < 0.05), and patients seemed to pay less attention to the degree of infraposition in their aesthetic assessments, as compared with most of the clinicians.

One-year results of a clinical and radiological prospective multicenter study on NEOSS® dental implants.

BACKGROUND: NEOSS® (Neoss Ltd., Harrogate, UK) dental implant system was introduced on the clinical arena in 2003. It is important that novel implant systems are systematically evaluated in a multicenter setting. PURPOSE: The aim of this study was to follow a large number of consecutively treated patients, with NEOSS dental implant system, both clinically and radiographically. The current report constitutes the 1-year data of a planned 5-year study. MATERIALS AND METHODS: The study included a total of 177 patients treated with 590 NEOSS implants at 13 clinics in Sweden. The material was composed of 72 males and 105 females treated for single, partial, and total edentulism. Clinical, radiographic, and subjective evaluations were performed. RESULTS: Out of 590 implants, 13 early failures have been reported, corresponding to a 1-year cumulative survival rate (CSR) of 97.8%. Evaluation of function and esthetics at the 1-year visit resulted in 100% success for function and 98% success for the esthetic outcome. The mean marginal bone loss was 0.6 mm (SD 1.1) after 1 year in clinical function. No adverse effects of the NEOSS dental implants were reported, and complications were few and similar to those reported for implant treatment in general. CONCLUSION: The CSR in the present study was 97.8%. No adverse effects of the NEOSS implants were reported, and complications during the study period were few and similar to those reported to for other well-documented implants system. Based on the present data, we conclude that NEOSS dental implant is a safe and predictable implant system. However, the high number of dropouts in the radiological evaluation must be considered when interpreting the data.

Long-term follow-up of CeraOne™ single-implant restorations: an 18-year follow-up study based on a prospective patient cohort.

BACKGROUND: Knowledge on long-term clinical performance of more than 5 years on the single-implant CeraOne™ (Nobel Biocare AB, Gothenburg, Sweden) concept is limited. PURPOSE: The aim of this study is to report the long-term clinical performance of the first CeraOne single-implant restorations, installed 17 to 19 years ago. MATERIALS AND METHODS: The group comprised 57 patients provided with 65 CeraOne single-tooth restorations. Sixty-two all-ceramic and three metal-ceramic crowns were cemented between 1989 and 1991. Patients were followed up clinically and with intraoral radiographs at placement, after 1, 5, and between 17 and 19 years after placement. RESULTS: Data were available for altogether 48 patients, followed up on an average time of 18 years. Excluding deceased patients (n=2) and failed implant patients (n=2), only five patients were lost to follow-up (8.8%). Two implants failed, resulting in an 18-year implant cumulative success rate (CSR) of 96.8%, and altogether eight original single-crown restorations were replaced (CSR 83.8%). The most common reason for crown replacement was infra-position of the implant crown (n=3). Many of the remaining original crowns showed various signs of implant crown infraposition at the termination of the study. In general, the soft tissue at the restorations was assessed to be healthy and comparable with the gingiva at the adjacent natural teeth. Bone levels were on an average stable with only few patients exhibiting bone loss of more than 2mm during 18 years in function. CONCLUSION: This long-term follow-up study of single-implant restorations shows encouraging results with few implant failures and minimal bone loss over an 18-year period. Original single-crown restorations were replaced more frequently, because of, for example, implant crown infraposition and veneer fractures. The CeraOne concept proved to be a highly predictable and safe prosthodontic treatment.

A long-term retrospective and clinical follow-up study of In-Ceram Alumina FPDs.

PURPOSE: The purpose of this study was to evaluate the long-term outcome of In-Ceram Alumina fixed partial dentures (FPD) performed in a general dental practice from 1992 to 1996. MATERIALS AND METHODS: The study was conducted as a retrospective assessment of up to 9 years of patient records and a clinical follow-up examination of patients treated with In-Ceram Alumina FPDs. In 37 patients, 42 FPDs had been inserted during the selected period. After randomized selection, 16 patients with 18 FPDs were examined clinically. The most common restorations comprised two and three units. Cantilever extensions were present on 64% of the FPDs. Sixty-two percent of the FPDs extended into the posterior region. RESULTS: The mean time in function for the 42 FPDs was 76 months (range 2 to 110 months), with 86% being followed for > 5 years. No adverse effects to either periodontal or pulpal tissues were recorded. The technical quality was very good, and patient satisfaction very high. Five FPDs fractured during the observation period, resulting in a total failure rate of 12%. Two of these FPDs fractured as a consequence of external trauma. Excluding these, the total survival rate during the observation period was 93%. Cumulative survival rate according to life table analysis was 93% after 5 years and 83% after 10 years. CONCLUSION: The results suggest that the In-Ceram Alumina short-span FPD is a viable prosthetic alternative.