Complications and Patient-Centered Outcomes of an Implant- Supported Single Crown after Immediate and Delayed Loading: A Systematic Review and Meta-analysis.

Single implants are a predictable treatment, and immediate loading can be an option with acceptable survival rates. Clinical and patient-centered outcomes comparing immediate and delayed protocol of single implants are unclear. The purpose of this study was to assess complications, satisfaction, and quality of life of patients rehabilitated with delayed and immediate loading single crowns. An electronic search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Embase databases up to February 2023. Only prospective studies, randomized and non-randomized clinical trials comparing immediate and delayed loading were included. For the quantitative analysis, dichotomous and continuous variables were evaluated with a 95% confidence interval. A total of 20 studies were evaluated. No statistically significant difference between protocols was observed: satisfaction (I2: 0%; P = 0.42), quality of life (I2: 0 %; P = 0.05), biological complications (I2: 9%; P = 0.17) mechanical complications (I2: 58%; P = 0.84), and survival rate (I2: 0%; P = 0.38). Subgroup analysis showed significant differences only for marginal bone loss when immediate implants were placed in the mandible (IÇ: 15%; P = 0.01) and posterior zone (I2: 0%; P = 0.001). Complications and patient-centered outcomes for immediate single-implant crowns were comparable to delayed loading. Scientific evidence showed no significant difference between loading protocols for survival rates. Although several factors could interfere with the complication events, implant failures, and marginal bone loss, the subgroup analysis evidenced that only immediate implants placed in the posterior mandible zone had higher statistically significant mean marginal bone loss.