Clinical outcomes of full-arch fixed implant-supported prostheses in patients lacking supportive peri-implant care: A cross-sectional study

Purpose: To evaluate the clinical outcomes and prosthetic complications in patients rehabilitated with full-arch fixed implant-supported prostheses according to the Columbus Bridge Protocol who did not adhere to a structured supportive peri-implant care programme. Materials and methods: This cross-sectional study included 56 patients (mean age 67.8 ± 9.2 years; 28.6% smokers; 80% response rate) rehabilitated with 229 implants (implant survival rate 100%) according to the Columbus Bridge Protocol. Patients were divided into three groups based on follow-up duration: 1 to 2 years (n = 19), 3 to 6 years (n = 16) and > 6 years (n = 21). Through a comprehensive examination, clinical parameters (probing depth, plaque index, bleeding on probing and keratinised tissue width) and mechanical and technical complications were examined by a single experienced operator. Plaque accumulation on the prosthesis was assessed through clinical images using a plaque disclosing solution and ImageJ software (National Institutes of Health, Bethesda, MD, USA). Finally, patient satisfaction was assessed using the Oral Health Impact Profile-14 scale. Results: Mean probing depth values remained stable across groups (2.03 to 2.49 mm, P = 0.125), with most sites ≤ 3 mm. No significant differences were found for bleeding on probing among groups (14.8% to 23.1%, P = 0.331). Plaque levels were high both at implant (43.8% to 57.1%, P = 0.233) and prosthesis level (42.9% to 47.0%, P = 0.707), with no significant differences between groups (P > 0.05). Keratinised tissue width ranged from 3.05 to 3.49 mm (P = 0.650). Prosthetic complications showed an increasing trend as follow-up duration increased (5.3% at 1 to 2 years, 18.8% at 3 to 6 years and 33.3% at > 6 years) (P = 0.086). Overall Oral Health Impact Profile-14 scores indicated a high level of patient satisfaction. Conclusions: Despite the lack of adhesion to a supportive peri-implant care programme, reflected by the high plaque values at implant and prothesis level, the Columbus Bridge Protocol resulted in positive clinical outcomes; however, prosthetic complications occurred and increased over time.