Biomechanical evaluation of osseointegration levels of grade-4 titanium and niobium alloy implants with different surface modifications

2. ABSTRACT BIOMECHANICAL EVALUATION OF OSSEOINTEGRATION LEVELS OF GRADE-4 TITANIUM AND NIOBIUM ALLOY IMPLANTS WITH DIFFERENT SURFACE MODIFICATIONS The search for effective treatment options for tooth loss has continued for decades, during which dental implant applications have been developed and successfully implemented, becoming one of the indispensable treatment modalities of modern dentistry. Unlike other prosthetic approaches, implant therapy offers the advantage of preserving the adjacent tooth structure and alveolar bone in the treated region, thereby standing out as a valuable treatment option. Furthermore, implant rehabilitation in cases of complete or partial edentulism has been reported to provide significant improvements in masticatory efficiency, phonation, esthetics, and overall quality of life. The most critical factor determining the long-term success of dental implants is osseointegration, the direct biological connection between the implant surface and surrounding bone tissue. This process plays a decisive role in the ultimate success of implant therapy and is influenced by numerous biological and biomechanical factors, particularly implant surface morphology. To enhance clinical performance, various surface modification techniques have been developed, thereby improving the biological outcomes of dental implants. The aim of this study was to compare the osseointegration levels of Grade-4 titanium alloy implants and niobium alloy implants with different surface modifications. The experimental animals were divided into six groups: Grade 4-SLA (n=9), Grade 4-turned (n=10), Grade 4-RBM (n=10), Nb-SLA (n=10), Nb-RBM (n=9), and Nb-turned (n=10). Under general anesthesia, implants with different surface characteristics (2.5 mm in diameter and 4 mm in length) were inserted into the cortico-cancellous bone of the metaphyseal region of the right tibia. After a healing period of twelve weeks, the animals were sacrificed, and the degree of osseointegration was assessed using a biomechanical reverse torque test. The findings revealed that osseointegration was achieved in all implants, both Grade-4 titanium and niobium alloys, after 12 weeks of healing. Turned surface implants exhibited significantly lower osseointegration levels in both alloy groups. No statistically significant difference was observed between SLA and RBM surface implants. However, when evaluated by alloy type, Grade-4 SLA surface implants demonstrated statistically higher osseointegration values compared to other groups. Keywords: Niobium, Grade 4, Implant surface, Osseointegration