Effects of grooved abutment on stability of implant abutment screw / 대한치과보철학회지

ABSTRACT

PURPOSE: The aim of this study was to investigate the effects of grooved abutments on abutment screw loosening. MATERIALS AND METHODS: This study was conducted to evaluate the abutment screw loosening after 6 months for 50 patients (51 implants) treated at the department of Prosthodontics in Yonsei University Dental Hospital from March, 2015 to July, 2015. A control group with non-grooved abutment consists of 30 implants, and an experimental group with grooved abutment consists of 21 implants. Astra, Straumann, Implantium, Osstem system were used in the study. The abutments with loose screws cases after a period of 6 months has been investigated, with two kinds of measurements 1) measuring the additional rotational angle on abutment during placement with the same force, 2) measuring the PTV on bucco-cervical area of implant crown. All data collected has been analyzed by normality test followed by Mann-Whitney test using SPSS program. RESULTS: No complications were reported after 6 months for the 51 implants. Abutment screw loose and crown fracture have not been seen in the study groups. The data collected from the two measurements showed no significant differences between the two groups with P-value 0.576 (average= control group 7.35°, experimental group 4.75°) for the additional rotational angle measurement and with P-value 0.767 for PTV. CONCLUSION: There are no significant differences between the grooved and non-grooved abutment in screw stability. However, further studies with long-term follow-ups and larger group of patients is needed in order to investigate the effects of grooved abutment on screw stability.