Nugteren, K.S. van (2018) SD-OCT and visual evaluation of full-coverage occlusal veneers made from chairside fabricated zirconia silicate hybrid composite vs direct composite overlays on humane extracted posterior elements. thesis, Dentistry.
Full text available on request.Abstract
Statement of problem: Recently, an economical zirconia silicate hybrid composite restoration is introduced on the dental market, which in theory combines some beneficial properties of direct and indirect restorations. Research on the performance of this product in terms of marginal integrity, anatomical contour and tooth-restoration adhesion compared to the conventional direct composite resins is not available. Objective: To evaluate the performance of a chairside fabricated full-coverage occlusal veneer made from zirconia silicate hybrid composite (One Visit Crown) in comparison to the traditional direct composite resin overlays (CR) on marginal integrity (MI) and anatomical contour (AC) on a macroscopic level, and to evaluate these materials on microscopic level on marginal integrity (MI-S), adhesion between tooth-restoration interface (AD) and defects within the restoration material (DEF). Furthermore, the effect of clinical experience on scoring is evaluated. Methods and material: Forty extracted human molars are prepared for an overlay restoration and an enamel/dentin etch-and-rinse 3 steps adhesive (Ultra-Etch, Optifil Primer and Bonding) was applied. Twenty of these molars were restored with a direct composite resin overlay (Clearfil AP-X) and twenty were restored with a hybrid zirconia silicate overlay with a preformed occlusal layer connected to the tooth with a light-curing adaptable interface (OVC) which were, after further curing and finishing extra-orally, cemented with Enamel Plus HFO. Samples were stored in water for several months. Five samples of each group were selected for visual-tactile examination by four senior dentistry students and four experienced dentists. Restorations were scored for marginal integrity (MI), anatomical contour (AC) and a prediction of chance of failure within five years (F) using a modified USPHS scoring. Other fifteen samples per group were cut in mesiodistal direction for SD-OCT imaging of the tooth-restoration interface. Each sample was scored on marginal integrity (MI-S), adhesion at tooth-restoration interface (AD) and defects within the restoration material (DEF) by one researcher. Furthermore difference between observers was evaluated. Results/Discussion: MI and AC were rated as ‘good’ for both materials and the overall predicted chance of failure within five years was 21-40%. CR material scored significantly more positive for MI (F(1, 38)=9.56; p=.004) and AC (F=(1, 38)=7.47; p=.010), but no significant difference in scoring for F has been found (F(1, 38)=.49; p=.503). Dentists score more positively for MI (F(1, 38)=7.81; p=.008) when compared to senior dentistry students. Dentists and senior dentistry students score similar for evaluation criteria AC (F(1, 38)=2.72; p=.108) and F (F(1, 38)=4.55; p=.066), but an interference of material on the way observer group scored AC (F(1, 38)=18.73; p=.000) and F has been observed (F(1, 8)=6.55; p=.034). Differences may have been caused by clinical experience and lack of experience with the OVC material. On SD-OCT images, means for MI-S, AD and DEF between the two materials did not differ statistically significant. Both materials show a tight tooth-restoration interface. Although not statistically significant, OVC material was more homogeneous when compared to CR. Within limitations of this study, both materials show promising results in terms of MI, AC, MI-S and AD, but further research is necessary to predict performance when adjacent teeth are present or on strength of the materials. Keywords: direct restoration, composite resin, hybrid
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Alting, Drs. H. |
| Faculty: | Medical Sciences |
| Date Deposited: | 23 Nov 2021 12:00 |
| Last Modified: | 23 Nov 2021 12:00 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2820 |
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