Title: Effect of Resin-coating on Adaptation of CAD/CAM-ceramic-crown Restoration for Molar
Chie Tokita (Presenter)
The Nippon Dental University
MEI KOMOTO, The Nippon Dental University
Seisuke Koshida, The Nippon Dental University
Masahiko Maeno, The Nippon Dental University
Toshio Maseki, The Nippon Dental University
Yoichiro Nara, The Nippon Dental University
Objectives: Good adaptation generally contributes clinical success of metal-free crown restoration. The purpose of this study was to examine the effect of resin-coating on adaptation of CAD/CAM-ceramic-crown restoration for molar.
Methods: A mandibular first molar melamine-resin tooth was prepared according to the general method for CAD/CAM-ceramic-crown restoration. 10 duplicated melamine-resin abutment specimens were precisely fabricated and were divided into two groups; resin-coating group (C+) and non-coating group (C-) (n=5 each). The abutment surfaces of C+ were sealed with an all-in-one adhesive system and a flowable resin composite (CLEARFIL Universal Bond Quick and CLEARFIL MAJESTY ES Flow, Kuraray Noritake Dental). Optical impression was taken in accordance with the manufacturer’s instructions, and each feldspathic-ceramic-crown (VITABLOCS MarkII, VITA) was fabricated by CAD/CAM system (CEREC AC Omnicam SW v4.3, and CEREC MC XL, Dentsply Sirona). The fabricated crowns were cemented to each individual abutment specimen with an adhesive resin-cement system (PANAVIA V5, Kuraray Noritake Dental). After 1 hour storage in water at 37°C, restored specimens were sectioned twice in bucco-lingual and mesio-distal dimensions, and every sectioned surfaces were polished with a series of SiC paper up to #2,000. The adaptation of crown was gauged at seven measurement points (restorative overlap-width at the cervical margin, six cement-thicknesses at cervical margin, middle of gingival-wall, ginginoaxial angle, middle of axial-wall, occlusoaxial angle, inner inclined occlusal-wall) with a light-microscope. The data were analyzed by Mann-Whitney's U test.
Results: The adaptation of C+ was significantly superior to C- at four measurement points (gingivoaxial angle, middle of axial-wall, occlusoaxial angle in the buccal portion and gingoaxial angle in the mesial portion). The cement-thickness in lingual and mesial portions has a tendency to be thinner than that of buccal and distal portions, regardless of resin-coating.
Conclusions: Resin-coating improved the adaptation of CAD/CAM-ceramic-crown restoration for molar.