The outcomes of the meta-analysis demonstrated high implant survival rates for both the single tooth implants and the respective single crowns after 5 and 10 years. However, technical, biological, and aesthetic complications were frequent.

OBJECTIVES: The objective of this systematic review was to assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological and technical complications. METHODS: An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow-up time of at least 5 years. Failure and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS: Twenty-six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta-analysis of these studies, survival of implants supporting SCs was 96.8% [95% confidence interval (CI): 95.9-97.6%] after 5 years. The survival rate of SCs supported by implants was 94.5% (95% CI: 92.5-95.9%) after 5 years of function. The survival rate of metal-ceramic crowns, 95.4% (95% CI: 93.6-96.7%), was significantly (P=0.005) higher than the survival rate, 91.2% (95% CI: 86.8-94.2%), of all-ceramic crowns. Peri-implantitis and soft tissue complications occurred adjacent to 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5-year observation period. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years, the cumulative incidence of screw or abutment loosening was 12.7% and 0.35% for screw or abutment fracture. For supra-structure-related complications, the cumulative incidence of ceramic or veneer fractures was 4.5%. CONCLUSION: It can be concluded that after an observation period of 5 years, high survival rates for implants and implant-supported SCs can be expected. However, biological and particularly technical complications are frequent. AbstractObjectives:The objective of this systematic review was to assess the 5 year survival of implant supported single crowns (SCs) and to describe the incidence of biological and technical complications. Methods:An electronic Medline search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow-up time of at least 5 years. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5-year proportions. Results:Twenty-six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta-analysis of these studies survival of implants Periimplantitis and soft tissue complications occurred in 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5 years observation period. Technical complications included implant fractures, connection-related and supra-structure related complications. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years the cumulative incidence of connection-related complications was 12.7% for screw or abutment loosening and 0.35% for screw or abutment fracture. For supra-structure related complications the cum...

It may be concluded that implant-supported fixed dental prostheses (FDPs) are a safe and predictable treatment method with high survival rates. However, biological and technical complications were frequent (33.6%). To minimize the incidence of complications, dental professionals should make great effort in choosing reliable components and materials for implant-supported FDPs and the patients should be placed in well-structured maintenance system after treatment.

The 5-year survival rates estimated from annual failure rates appeared to be similar for ceramic and metal abutments. The information included in this review did not provide evidence for differences of the technical and biological outcomes of ceramic and metal abutments. However, the information for ceramic abutments was limited in the number of studies and abutments analyzed as well as the accrued follow-up time. Standardized methods for the analysis of abutment strength are needed.

Objectives: The aim was to test whether or not zirconia abutments exhibit the same survival and technical/biological outcome as titanium abutments. Material and methods: Twenty‐two patients receiving 40 single‐tooth implants in canine and posterior regions were included. The implant sites were randomly assigned to 20 zirconia and 20 titanium abutments. All‐ceramic and metal–ceramic crowns were fabricated. At baseline, 6, 12 and 36 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque control record (PCR) and bleeding on probing (BOP) were assessed at abutments (test) and analogous contralateral teeth (control). Standardized radiographs of the implants were made and the bone level (BL) was measured referring to the implant shoulder on mesial (mBL) and distal sides (dBL). The difference of color (ΔE) of the peri‐implant mucosa and the gingiva of control teeth was assessed with a spectrophotometer. The data were statistically analyzed with Mann–Whitney Rank and Student's unpaired t‐tests. Results: Eighteen patients with 18 zirconia and 10 titanium abutments were examined at a mean follow‐up of 36 months (range 31.5–53.3 months). No fracture of an abutment or loss of a reconstruction was found. Hence, both exhibited 100% survival. At two metal–ceramic crowns supported by titanium abutments chipping of the veneering ceramic occurred. No difference of the biological outcome of zirconia and titanium abutments was observed: PPD ( 3.2 ± 1 mm, mPPDTi 3.4 ± 0.5 mm), PCR ( 0.1 ± 0.2, mPCRTi 0.1 ± 0.2) and BOP ( 0.4 ± 0.4, mBOPTi 0.2 ± 0.3). Furthermore, the BL was similar at implants supporting zirconia and titanium abutments ( 1.7 ± 1, 1.6 ± 1; mBLTi 2 ± 1, dBLTi 2.1 ± 1). Both, zirconia and titanium abutments induced a similar amount of discoloration of the mucosa compared with the gingiva at natural teeth ( 9.3 ± 3.8, ΔETi 6.8 ± 3.8). Conclusions: At 3 years, zirconia and titanium abutments exhibited same survival and technical, biological and esthetical outcomes.