Statistical analysis
CBL loss, PD
PLAQUE, REGRESSION, SECONDARY, REGRESSION
Data was entered into MS-Excel, proofed for entry errors, and imported into Stata (Stata version 17, StataCorp LLC, College Station, TX, USA). All data analyses were performed by a statistician (SAL) at Bergen University who had not participated in data collection or processing. Primary outcome variables were PD (mean of six sites/implant) and CBL loss (mean of mesial and distal recordings). Plaque, BoP, SUP, PCF, and VAS scores were defined as secondary outcome variables. Additionally, PD was dichotomized as < 6 mm and ≥ 6 mm and analyzed as a categorical variable.Descriptive statistics were calculated separately for the two groups at different time points at baseline, and at 6 and 12 months. Chi-square tests were used to identify differences for categorical variables at baseline, while t-tests were applied for continuous variables. To test changes over time and differences between groups, adjusted multivariable regression analyses, including robust variance estimates to adjust for repeated (multiple) observations for each individual, were applied. The continuous outcomes were analyzed using linear models, while categorical variables were analyzed using logistic regression models. Regression analyses including other potential risk factors were performed to explore if any of these predicted the outcome variables. P-values less than 0.05 were considered statistically significant.