Randomization and statistical analysis
Statistical analysis was performed using the Stata program version 13 (StataCorp LP: College Station, TX, USA); the significance level for all tests was p < 0.05. To detect a mean difference of 0.5 standard deviation on the numerical tolerance scale, with a power of 0.85 and type 1 error rate of 0.05, we needed 2 groups of 74 participants. The randomization plan was so as to have 33% more participants in the DSG + ENG-IMPLANT group, with a 1:3 ratio, because of 35% drop out in the ENG-IMPLANT group. This would have provided a power of 0.8 to detect a difference in proportions with implant removal of 0.35 versus 0.15 to compensate for possible loss to follow-up. Sample size was set to 80 participants in the ENG-IMPLANT only group, and 120 in the DSG + ENG-IMPLANT group. Randomization was conducted on For continuous variables, means and standard deviation (SD) were calculated; for categorical data, proportions were calculated. The chi-square test and Fisher´s exact test were used when appropriate, as well as the student’s 