임플랜트 보철물과 자연치사이의 인접접촉강도의 경시적 변화

Abstract

Ideal proximal contacts between neighbouring teeth contribute to maintenance of the stability of dental arches and healthy periodontal tissue. Tightness of proximal tooth contact(TPTC) in natural dentition was checked by some special devices. Previous study have shown that teeth pulsate in the dental alveoli at rest, mainly because of the circulation of blood in the periodontium. In contrast with natural teeth, osseointegrated dental implants are not equipped with periodontal mechanoreceptors. Proximal contact loss between the adjacent natural tooth and a fixed implant prothesis can be experienced during treatment, especially in the case of posterior prostheses after implant placement. Therefore it is considered that the quantitative evaluation of the TPTC on implant prothesis is necessary. Purpose: The aim of this study was to evaluate time serial change of the TPTC between the implant prosthesis and natural tooth at rest state. Materials and methods: Thirty-one patients(19 males and 12 females; mean age, 48.2 years) restored with a total 31 single-implant crowns in the left maxillary for 13 single-implant and left mandibular second molars for 18 single-implant crowns, respectively were selected. All implants were 3i parallel walled implants of internal connection and were longer than 11.5 mm and had a diameter 4.0 mm. All abutments were screw-retained UCLA gold (hexed) abutments. All superstructures were gold-alloy full cast crowns. All subjects had a natural interproximal tooth surface between the left first molar and the implant prosthesis in both the maxilla and mandible. The TPTC was checked directly after delivery, 1 month after delivery and 6 months after delivery of prothesis at rest state. The measurement was repeated five times at same area. Among these values, the highest and the lowest values were excluded, then the mean value of the other three measured values was determined as the representative value in each contact area. Frideman test was used to compare the values. Results: The TPTC decreased significantly as time goes by both maxilla(p<.01) and mandible(p<.05). Conclusions: The TPTC between the implant prosthesis and natural tooth decreased as time goes by after fixed implant prothesis placement.