The relationship of peri-implant soft tissue wound healing with implant cover screw design: Cross-sectional study

INTRODUCTION

Dental implants are frequently preferred method for oral rehabilitation all over the world. The incidence of various complications such as incorrect prosthesis, peri-implant mucositis, and peri-implantitis is high; premature loss of implants is encountered due to osteointegration process not being completed for some unexplained reasons. However, there is no study in the literature examining the nonfunctional period of implants. Closure screws of different implant companies have different designs like surface properties, and areas, where closure screws sit, are important reservoirs for microorganism colonization. Our study aims to evaluate the inflammatory response, epithelial maturation, and epithelial-connective tissue interaction around closure screws.

METHODS

For this purpose, 52 implants belonging to five different implant companies were included in the study. Tissues removed over the cover screw during fitting of healing caps were used as biopsy material and for epithelial proliferation Ki-67, for epithelium-connective tissue interaction Syndecan-1, and for macrophage activation CD-68 expressions were evaluated by immunohistochemical analysis. Scanning electron microscopy (SEM) analyzes were performed to evaluate the presence of gap between the implant and the cover screw.

RESULTS

As a result of our study, intensity of subepithelial inflammation between groups wasn't statistically different. Differences in CD-68 and Syndecan-1 levels were obtained at the lamina propria level. H score of CD-68 was statistically significantly different in epithelium (p = 0.032), and H score of Syndecan-1 was different in lamina propria (p = 0.022). There wasn't a statistically significant difference between the groups for Ki-67 (p = 0.151).

CONCLUSION

Our study results indicate that in addition to the implant surface morphology, the design of the closure screws is important in the inflammatory response and epithelial maturation that develops during wound healing. Although the inflammatory response is required for healing, osteointegration, and implant survival, further investigation is needed to investigate the relationship between initial neck resorption and closure screws with radiographic and microbiological examinations.

[CPITN in a group of Ankara University students]

Several index systems have been used for the identification of periodontal diseases and assessment of periodontal treatment needs up to date. In 1982 World Health Organization and FDI have developed a new index system for the assessment of periodontal treatment needs "Community Periodontal Index of Treatment Needs" (CPITN) which was well adapted for the field studies. Because of it's being an universe and practical system, it has been the common language of periodontists in a few years. Our study which was carried out on the 271 students of Ankara University from each sex group using CPITN criteria have shown a wide spread of periodontal diseases among these students and 50 percent of code 2 treatment needs.