Marginal bone loss around posterior implants in correlation with loading protocols and prosthetic material

The aim of this study was to analyze the long-term influence of early and delayed loading protocols and the prosthetic material on marginal bone loss around implants, restored with cemented fixed dental prostheses (FDPs) in posterior maxilla and mandible. In 20 patients, 10 men and 10 women, implants were inserted in the posterior regions and loaded with metal-ceramic and zirconia FDPs. An early loading protocol was applied in patients without augmentation, while a delayed loading protocol was implemented in patients with late implantation and bone grafting. The radiographic peri-implant bone levels were analyzed in correlation with the loading protocol and the chosen prosthetic material after 2nd year and 10th year of loading. Gender, age and smoking habits of patients were noted as influencing factors. The 55 implants were restored with 25 cemented FDPs, 12 in the upper lateral jaw and 13 in the lower lateral jaw. After 10 years of follow-up, all implants survived, while the success rate of implants and cemented bridges was 94.55% and 96% respectively. After 2 years, the implants restored with metal-ceramic FDPs showed significantly bigger marginal bone loss distally than in the implants restored with zirconia FDPs. After 10 years, 3 implants restored with metal-ceramic bridges showed radiographic excessive bone loss, whereas 1 bridge had fracture of veneering porcelain. The early loading of implants with cemented FDPs was proved to be a successful protocol. The choice of material affected the biological results, since the implants restored with metal-ceramic bridges presented significantly greater marginal bone loss distally than the implants restored with zirconiа FDP. Smoking, gender and age had no significant effect on late marginal bone loss.