Technique sensitivity hampers outcomes in periodontal regeneration when performed by less experienced operators: A retrospective analysis

Flap design is a key factor in the clinical outcomes of periodontal regeneration (PR). This study compares the effectiveness of minimally invasive flap (MIF) to conventional flap (CF) techniques in PR procedures performed by periodontic residents. The study also addresses how technique sensitivity may influence clinical outcomes when performed by less experienced operators. A retrospective study was conducted on patients who underwent PR from January 2012 to January 2023 at the School of Dentistry, University of Michigan. Flap techniques were classified as MIF or CF, and clinical outcomes, including bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), gingival recession (GR), changes in keratinized gingiva, and tooth loss, were evaluated. Statistical analysis using generalized estimation equations was performed for the overall sample and separately for each group. The study sample consisted of 40 male (45.5%) and 48 female patients (54.5%), with an average age of 63.1 ± 13.8 years and a mean follow-up of 42 months. No significant differences were found between the MIF and CF groups regarding the reduction in PD or GR. However, the CF group exhibited a superior gain in CAL (p=0.005) and a greater decrease in BOP after adjustment for confounders (odds ratio: 4.44, p=0.0276). Tooth type and defect depth were identified as significant factors affecting clinical outcomes. Both techniques were effective in treating periodontal defects. However, the CF approach demonstrated a greater improvement in CAL and BOP. Given the technique-sensitive nature of MIF, the limited clinical experience of resident operators may have contributed to the diminished performance of MIF observed in this study. Simpler surgical techniques may offer comparable effectiveness to more complex, superior surgical techniques in a university-based setting when performed by less experienced operators.