Influence of 3D interrelationships on biological and prosthetic complications.

Background: Certain 3D interrelationships between adjacent implants can potentially predispose to prosthetic and biological complications.

Materials and methods: Patient records with adjacent dental implants were assessed to evaluate the effects of vertical, horizontal and angulation interrelationships between splinted compared to non-splinted implant restorations on the occurrence of biological and prosthetic complications. Data on patient- and implant-related variables were collected at baseline (T1) during prosthesis placement and at the last follow-up appointment (T2).

Results: The study included 227 patients with 508 implants and a mean follow-up period of 6.7 ± 6.5 years. No significant difference in implant survival was observed between the groups (97.3% for splinted adjacent implant restorations and 98.4% for non-splinted adjacent implant restorations). Implant success, defined as the absence of any biological or prosthetic complications, was relatively low (56.8% for non-splinted adjacent implant restorations and 62.1% for splinted adjacent implant restorations), with no significant inter-group differences (odds ratio 0.80; P = 0.415). Patients with splinted adjacent implant restorations demonstrated a significantly higher likelihood of biological complications than those with non-splinted adjacent implant restorations (24.1% vs 12.6%, respectively; odds ratio 2.21; P = 0.028) but a notably lower risk of prosthetic complications (19% vs 33.3%, respectively; odds ratio 0.47; P = 0.015). Survival and success rates were consistent across both groups at both patient and implant levels. Generally, certain 3D interrelationships were linked to biological complications in the splinted adjacent implant restoration group and prosthetic complications in the non-splinted adjacent implant restoration group. With regard to marginal bone loss according to implant location, the middle implant was found to have increased marginal bone loss compared to its mesial or distal counterpart (P = 0.013)Conclusion: Certain 3D relationships were found to exacerbate prosthetic complications in non-splinted adjacent implant restorations and biological complications in splinted adjacent implant restorations. Implants with either type of restoration exhibited comparable survival and success rates.

Conflict-of-interest statement: The authors declare there are no conflicts of interest relating to this study.