Is there a learning curve in static computer-assisted implant surgery? A prospective clinical study.

Static computer-assisted surgery (s-CAS) has been introduced to improve the results of implantology. A prospective cohort study was conducted following the STROBE guidelines to determine the presence of a learning curve in s-CAS. Six partially and six totally edentulous patients were treated by two surgeons experienced in implantology but completely inexperienced in s-CAS. Preoperative and postoperative computed tomography scans were matched to assess coronal, apical, and angular deviation and the positioning error. The accuracy data were used to evaluate the learning curve. Fifty-six implants were inserted. In partially and totally edentulous patients, the mean (range; standard deviation) coronal deviation was 0.87 (0.34-1.27; 0.35) and 1.24 (0.72-2.67; 0.79); the mean apical deviation was 1.13 (0.48-1.63; 0.39) and 1.52 (0.88-3.84; 1.15); the mean angular deviation was 2.63 (1.89-4.50; 0.98) and 3.59 (1.69-6.30; 1.65); and the mean positioning error was 0.80 (0.32-1.25; 0.35) and 1.14 (0.35-2.56; 0.77), respectively. A typical 'learning curve' effect was not identified for s-CAS.

Is a two-month healing period long enough to achieve osseointegration? A prospective clinical cohort study.

The aim of this study was to evaluate the effectiveness of loading at 2 months after the surgical placement of implants. A tapered implant was used. Implant stability was determined using resonance frequency analysis at implant insertion (T0; primary stability), after 2 months (T1), and at the 6-month follow-up (T2). Descriptive statistics and the t-test were used. Significance was at P ≤ 0.05. A total of 268 implants were inserted in 142 patients. No patient dropped out and no implant had failed at the 6-month follow-up. The mean implant stability quotient value (ISQ) increased over time, with a statistically non-significant difference for T0 vs. T1 (P = 0.08) and a statistically significant difference for T1 vs. T2 (P = 0.0018) and T0 vs. T2 (P = 0.000). Only 99 implants, characterized by an extremely high mean primary stability value (80.34), did not have a recorded increase in ISQ at T1. A 2-month healing period allowed the implant to achieve secondary stability, confirming the effectiveness of the loading protocol at 2 months.

Peri-implant bone loss around platform-switched Morse taper connection implants: a prospective 60-month follow-up study.

The aim of this study was to measure the crestal bone level changes at 60 months of follow-up and to evaluate the influence of biologically relevant, anatomical, and implant-related variables. A prospective study design was used. STROBE guidelines were followed. A total of 576 implants were inserted in 270 patients needing an implant-supported, partial, fixed dental prosthesis or a single crown. Standardized peri-apical radiographs were obtained at 2 months (time of implant-abutment connection and prosthetic loading) and 60 months of follow-up. Descriptive statistics were used and inter- and intra-examiner reliability determined. A mixed model was used to evaluate the predictor variables. The correlation among multiple implants inserted in a single patient was considered. Significance was assessed using the type 3 test. Sensitivity analyses, least-squares means analyses, t-tests, and χ2 tests were also conducted. The statistical analysis was performed at the implant level; P<0.05 indicated statistical significance. At the 60-month follow-up, the mean marginal bone remodelling was -0.59±1.34mm (range -5.70 to 3.65mm). Marginal bone loss was significantly influenced by implant depth, implant location, and the interactions implant depth×jaw, implant location×timing of implant placement, and jaw×implant diameter. At the 60-month follow-up, a low mean marginal bone loss was found, which was significantly higher with subcrestal implants and anterior implants.