Statistical analysis
bone loss
BONE LOSS
The sample size was calculated for detecting a mean difference between test and control groups in radiographic marginal bone level changes of 1 mm with a standard deviation (SD) of 1.25 mm, an alpha error of 0.05, and a statistical power of 80% (G*Power 3.1 Software). After a pilot study with 10 patients comparing both groups with a mean marginal bone loss in the test group of 1.25 ± 1.25 mm and in the control group of 2.37 ± 0.69 mm, the resulting sample size was 28. Each patient was randomized to receive one of the two types of implants by means of a computer-generated random list and by blocks of four treatments each. Allocation concealment was assured using opaque sealed envelopes that were opened immediately after implant site preparation.Descriptive statistics (mean values, standard deviations, medians, and 95% confidence intervals) of variables were performed for each group using a statistical software program (SPSS version 25.00; IBM, USA). The implant was considered the unit of analysis. The normality was assessed by means of a Kolmogorov–Smirnov test and was found to be normally distributed. The 