Five-year retrospective study on success, survival and incidence of complications of single crowns supported by dental implants.

OBJECTIVE: To determine the survival and the incidence of biologic and technical complications of implant-supported single crowns after 5 years of function. MATERIAL AND METHODS: Patients treated with dental implants at the National Dental Centre, Singapore, from 2006 to 2010 were recruited from the Implant Registry and evaluated by two clinicians. One hundred and ninety-four patients, with 266 implant single crowns (SCs), were examined clinically for biologic and technical parameters. Digital radiographs were also obtained. Failure and complication rates were calculated based on the person-time at risk. RESULTS: The mean biologic time in function was 5.9 ± 1.3 years. None of the implants had been lost, resulting in a 5-year survival of 100%. The corresponding success (complication-free) rate was 92.9% (95% CI: 89.2, 95.4). The mean prosthetic time in function was 5.2 ± 1.5 years, with a 5-year survival of implant-supported SCs of 98.2% (95% CI: 95.8, 99.3). The corresponding success rate was 88.9% (95% CI: 84.8, 92.0). The 5-year incidence of biologic complications, defined as PPD ≥6 mm with bleeding on probing/suppuration, in the presence of ≥2.5 mm of radiographic bone loss, was 7.1% (95% CI: 4.6, 10.9). The 5-year incidence of technical complications was 6.5% (95% CI: 3.9, 10.7) for fracture of the veneering material, 4.3% (95% CI: 2.4, 7.7) for loss of retention, 2.1% (95% CI: 1.0, 4.7) for abutment screw loosening and 0.4% (95% CI: 0.1, 2.5) for abutment fracture. CONCLUSIONS: High survival rates (98.4%) for both the single tooth implants and the respective single crowns were demonstrated after 5.2 ± 1.5 years. However, the success rates were considerably lower (84.9%), indicating that biologic and technical complications were frequent.

Patient-related outcome measures with implant therapy after 5 years.

OBJECTIVE: To analyze patients' perception of implant therapy in partial edentulism, after 5 years with implant-supported reconstructions. MATERIAL AND METHODS: Patients who received dental implants at the National Dental Centre, Singapore 3-9 years earlier (mean: 5.2 years) were invited to participate in the study. Responders were examined clinically, and asked to answer a questionnaire with 13 statements. RESULTS: Of the 880 patients, 206 patients, with 329 implants, agreed to participate. Of the implants, 82% supported single crowns, while 18% were reconstructed with splinted crowns or fixed dental prostheses. Function and chewing comfort yielded high patient satisfaction. Comparing chewing comfort for teeth and implants, respectively, 51% perceived no difference between the two. Patients were largely satisfied with the phonetic function and esthetic outcome. Only two in three patients were able to cleanse the implant reconstruction well, and majority of the patients reported no difference comparing the time taken to clean implants and teeth. Patients were generally unsure if the tissues around their implants or teeth bled more. Pertaining to expectations, most patients were satisfied with the treatment, and majority were willing to undergo the same treatment again. Most patients would recommend such treatment to friends, if indicated. Only slightly over one-third of the patients felt certain that the cost of the treatment was justified. CONCLUSION: The large majority was satisfied with the functional outcomes of implant treatment. However, the patients had a less than ideal understanding of gingival health around teeth and implants. Patients were less discerning than clinicians in the assessment of esthetic outcomes.