Long term clinical results of intrabony defects treated with periodontal regeneration. A retrospective analysis based on composite outcome measure

Objectives: To report the long-term results of intrabony defects following periodontal regenerative therapy up to 7-years using composite outcome measure (COM). Materials and methods: Clinical charts of 19 patients with 29 periodontal intrabony defects treated using periodontal regeneration were selected for the analysis. The intrabony defects were treated using different flap designs (extended flap with simplified papilla preservation technique, minimally invasive surgical technique or modified minimally invasive surgical technique) and different regenerative treatments (guided tissue regeneration, enamel matrix derivative or deproteinized bovine bone mineral combined with enamel matrix derivative) were applied. Full-mouth plaque score (FMPS, full-mouth bleeding score (FMBS), clinical attachment level (CAL), probing depth (PD), and gingival recession (GM) were recorded at baseline, at 1, and 7 years. The effects of periodontal regeneration were evaluated according to COM values at 1 and 7 years. Intrabony defects were classified as COM1 (i.e. CAL gain ≥ 3 mm, PD ≤ 4 mm), COM2 (i.e. CAL gain < 3 mm, PD ≤ 4 mm), COM3 (i.e. CAL gain ≥ 3 mm, PD > 4 mm), COM4 (i.e. CAL gain < 3 mm, PD > 4 mm). The primary outcome was COM change. Treatment success was defined as a site displaying a CAL gain ≥ 3 mm and a PD ≤ 4 mm (COM 1). Results: After 7 years, a statistically significant improvement was observed in all clinical parameters (p < 0.05). At 1- and 7-years follow-up, the proportions of defects considered COM1 (i.e. treatment success) were 75.9% and 44.8%, respectively. After 1 year following regenerative therapy, 3.4% of the defects were defined as COM2 and COM3, while 17.2% of the sites was assigned to COM4. At 7 years, the proportion of defects in COM2 and COM4 was 27.6% in each group, whereas no defects showed a COM3 value. Conclusions: Within limits of the present study, the results indicated that the clinical benefits obtained following regenerative therapy can be maintained on a period of 7 years. However, the treatment success (i.e. COM1) was not always achieved. Clinical relevance: Despite a relevant CAL gain (i.e. CAL gain ≥ 3 mm), the presence of residual pockets (i.e. PD > 4 mm) following periodontal regeneration could determine a worsening of clinical parameters during supportive periodontal care.