“Influence of peri-implantitis defect angles on morphology and the biocompatibility of the implant surfaces after Er, Cr: YSGG laser therapy: an ex vivo study”

PURPOSE: The key obstacles in peri-implantitis therapy are the decontamination of the previously infected implant surface, surface integrity preservation, and enhanced biocompatibility. All are essential events for positive re-osseointegration. The principal hypothesis is that diverse peri-implantitis defect angles may affect the effectiveness of Er, Cr: YSGG laser therapy in a 3D-printed model of peri-implantitis. The primary objective of this study was to evaluate implant morphological changes through profilometer analysis with atomic force microscopy. The biological response (biocompatibility) assessment via the cell culture process to determine human osteoblasts (Saos-2) attachment, differentiation, and mineralization was the secondary objective. MATERIALS AND METHODS: 50 mJ (1.5 W/30 Hz), 50% air, 40% water, and five cycles at five minutes were applied in the decontamination procedure with an Er, Cr: YSGG side-firing laser tip. This was applied to twenty-four tested implants. They were split into four test groups with peri-implant infrabony defect angles of 15°, 30°, 60°, and 90°. These defects were customized in a 3D-printed model. As controls, two native implants were examined. RESULTS: There was no significant difference in implant surface roughness between the control and four tested groups. There was a slight reduction in implant surface roughness concerning 60-degree bone defect angulation. There was high alkaline phosphatase enzyme (ALP) activity, high osteoprotegerin (OPG) protein and gene expression, and the lowest soluble receptor activator of nuclear factor-kB ligand (RANKL) protein and gene expression in the 60-degree bone defect compared to other bone defect angulations. CONCLUSION: Er, Cr: YSGG laser therapy in the decontamination procedure of previously contaminated implants in peri-implantitis therapy is successful in preserving the implant surface integrity in diverse peri-implantitis defects without major surface roughness alterations; it shows favorable biocompatibility with an appropriate osteogenic response in the four studied groups. The 60-degree bone defect shows slightly enhanced surface roughness and osteogenic response. Defect angulation influences the surface roughness and cell response. The new pristine implant still had a superior cellular response compared to the previously decontaminated implant surface. CLINICAL RELEVANCE (SCIENTIFIC RATIONALE FOR STUDY): Peri-implantitis is a severe form of periodontal disease that affects the bone around dental implants. The primary challenge with this disease is cleaning the contaminated surface without causing further damage, allowing bone to grow, and maintaining the implant stability. In other words, the key issue for peri-implantitis treatment is maintaining a biocompatible implant surface during cleaning. If the implant surface is damaged, bone will not grow well. This study investigates the cleaning of an infected implant surface using the Er, Cr: YSGG laser, examines whether it maintains surface safety and functionality during decontamination of different bone defect shapes, and investigates the ability of osteoblasts to grow and attach to cleaned implants. Knowledge of how variations in bone defect shape affect cleaning outcomes and cellular responses will aid clinicians in selecting the most appropriate treatment modality for patients with peri-implantitis. CLINICAL TRIAL REGISTRATION: " Efficacy of Er: YSGG Laser in Treatment of Peri-implantitis". CLINICALTRIALS: gov ID: NCT05137821. First Posted date: 30 -11-2021.