Prospective randomized controlled clinical study comparing two types of two-piece dental implants supporting fixed reconstructions-Results at 5 years of loading.

ABSTRACT

OBJECTIVES: Compare clinical outcomes of two types of dental implants with non-matching implant-abutment junctions loaded with fixed implant-borne reconstructions at 5 years of loading. MATERIALS AND METHODS: In 64 patients, one of two implant systems (S1, S2) was randomly used to support fixed dental prostheses (FDP). At loading (TL ), after 1 (T1 ), 3 (T3 ) and 5 years (T5 ), the implant and reconstruction survival, biological and technical complications, radiographic marginal bone levels, clinical outcomes were recorded. The implants of the groups S1 and S2 contained of two-piece titanium implants with a non-matching implant-abutment junction. Data were analyzed on the patient level (1 implant/patient) using the non-parametric Wilcoxon-Mann-Whitney test. RESULTS: Ninety-seven implants were placed and loaded with fixed reconstructions in 64 patients. At T5 , 29 S1 and 28 S2 implants were available for the patient-level analysis. Two implants in group S1 had to be removed in the same patient due to severe peri-implantitis, resulting in a survival rate of 96.1% on the implant level and 96.6% on the patient level. No implant in group S2 was lost. The technical complication rate on patient-level amounted of 24.2% (S1) and of 6.5% (S2) (p > .05). Biological complications on patient-level were observed in 15.2% (S1) and 16.1% (S2) (p > .05). From TL to T5, the medians of the mean marginal bone level changes wer a gain of 0.15 mm in group S1 and a loss of 0.14 mm in group S2 (p > .05). CONCLUSIONS AND CLINICAL IMPLICATIONS Both implant systems revealed high survival rates and minimal changes of the marginal bone levels during 5 years. Few biological complications occurred in both groups. S1 revealed a high rate of technical complications. Therefore, both implant systems can be recommended for fixed reconstructions.