임프란트 보철물의 인접면 접촉 강도의 평가

Abstract

Ideal proximal contacts between neighbouring teeth contribute to maintenance of the stability of dental arches and healthy periodintal 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. Therefore it is considered that the quantitative evaluation of the TPTC on implant protheses is necessary. Purpose: The aim of this study was to evaluate the TPTC using a novel device at rest state on implant prostheses. Materials and methods: 1) TPTC between the natural teeth; Ten healthy young adults(5 males and 5 females: mean age, 27.1 years) with class I normal occlusion consented to participate in the study. 2) TPTC between the natural tooth and implant prosthesis; This group comprised twenty patients(14 males and 6 females; mean age, 47.4 years), restored with a total 20 single-implant crowns in the left maxillary and mandibular second molars for 10 single-implant crowns, respectively. 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. Test area were divided by 4 groups. UM describes the contact between the upper natural left first molar and natural second molar; LM the contact between the lower natural left first molar and natural second molar; IUM the contact between the upper natural left first molar and implant second molar and ILM the contact between the lower natural left first molar and implant second molar. The TPTC was measured at rest state in each area. This trial performed 3 month after delivery of superstructure and 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. One-way ANOVA was used to compare the values in each group. Results: The mean TPTC of the UM, LM, IUM and ILM was 1.48(±0.44) N, 1.78(±0.40) N, 1.14(±0.37) N and 1.30(±0.32) N respectively. There was a statistically significant difference in TPTC between LM and IUM (p<.01), beetween LM and ILM (p<.05). Conclusions: The quantitative evaluation of the TPTC on implant prostheses was tried by a newly developed device. These results indicate that the TPTC was less between natural tooth and implant prosthesis than between natural teeth.