Purpose: To analyze the presented evidence behind suggested reasons for long-term marginal bone loss (MBL) around 600 endosseous titanium dental implants according to the radiological findings up to 60 months.
Materials and methods: The data of 151 patients are received from the prosthodontic department of a university clinic and analyzed for the effect of implant brand, location, implant diameter and length, implant occlusal table width, cantilever, and smoking on MBL in a 6-year period.
Results: MBL is significantly higher in Zimmer SwissPlus implant system. The bone loss in posterior region was higher than anterior region for maxilla. There was no significant difference in mandible. Kruskal-Wallis test showed that MBL was significantly higher when the crown/implant (C/I) ratio was 1.5/2 (P < 0.05). Occlusal table width/implant diameter (OT/I) ratio was analyzed and it showed that MBL was significantly higher when the ratio was 2.5 to 2.99 and higher than 3. There were no significant associations between smoking and nonsmoking groups. Mann-Whitney U test revealed that cantilever does not affect MBL.
Conclusion: The marginal bone loss is affected by location of the implants (higher in the maxillary posterior region). In addition, excessive C/I and OT/I ratios increase marginal bone loss.