Dentists’ Perspectives on Defining Failure in Implant-Prosthodontic Therapy: A Cross-Sectional Study

Aim: to investigate the criteria to define implant–prosthodontic therapy failure for dentists in Croatia. Methods: We conducted a cross-sectional study using an online questionnaire among dentists in Croatia. The questionnaire consisted of demographic information and sections about experience and criteria for defining outcomes in implant–prosthodontic therapy to assess dentists’ perspectives towards implant failures, failure of prosthodontic supra-structures, potential complications and follow-up time. Descriptive statistics were used and differences were assessed using Chi-squared statistics. Results: Overall, 198 dentists completed the questionnaire, most of whom were general practitioners (81.8%), and mostly females (68.2%). 63.1% reported having worked with implants in their everyday practice. Most dentists (71.2%) have encountered implant failure, and more than half (57.1%) experienced a failed prosthodontic supra-structure. However, their definitions of implant failure or success differed significantly. Criteria for failure from 1986 were considered among 47% dentists, while 53% considered the implant to be successful if it remained in situ over a follow-up period. The three postoperative complications which patients should be warned about included pain, swelling and periimplantitis. Follow-up at six months and at five years were both chosen as appropriate by approximately the same number of dentists. Conclusions: Criteria to define implant failure differed between general practitioners and specialists, while definitions of implant success correlated with experience. The variability observed underscores the need for standardized education and unified assessment criteria to improve clinical consistency and communication.