Bonding to new CAD/CAM resin composites: influence of air abrasion and conditioning agents as pretreatment strategy

Clin Oral Investig. 2019 Feb;23(2):529-538. doi: 10.1007/s00784-018-2461-7. Epub 2018 Apr 27.

Abstract

Objectives: Because of their industrially standardized process of manufacturing, CAD/CAM resin composites show a high degree of conversion, making a reliable bond difficult to achieve.

Purpose: The purpose of this experiment was to investigate the tensile bond strength (TBS) of luting composite to CAD/CAM resin composite materials as influenced by air abrasion and pretreatment strategies.

Material and methods: The treatment factors of the present study were (1) brand of the CAD/CAM resin composite (Brilliant Crios [Coltene/Whaledent], Cerasmart [GC Europe], Shofu Block HC [Shofu], and Lava Ultimate [3M]); (2) air abrasion vs. no air abrasion; and (3) pretreatment using a silane primer (Clearfil Ceramic Primer, Kuraray) vs. a resin primer (One Coat 7 Universal, Coltene/Whaledent). Subsequently, luting composite (DuoCem, Coltene/Whaledent) was polymerized onto the substrate surface using a mold. For each combination of the levels of the three treatment factors (4 (materials) × 2 (air abrasion vs. no air abrasion; resin) × 2 (primer vs. silane primer)), n = 15, specimens were prepared. After 24 h of water storage at 37 °C and 5000 thermo-cycles (5/55 °C), TBS was measured and failure types were examined. The resulting data was analyzed using Kaplan-Meier estimates of the cumulative failure distribution function with Breslow-Gehan tests and non-parametric ANOVA (Kruskal-Wallis test) followed by the multiple pairwise Mann-Whitney U test with α-error adjustment using the Benjamini-Hochberg procedure and chi-square test (p < 0.05).

Results: The additional air abrasion step increased TBS values and lowered failure rates. Specimens pretreated using a resin primer showed significantly higher TBS and lower failure rates than those pretreated using a silane primer. The highest failure rates were observed for groups pretreated with a silane primer. Within the Shofu Block HC group, all specimens without air abrasion and pretreatment with a silane primer debonded during the aging procedure.

Conclusions: Before fixation of CAD/CAM resin composites, the restorations should be air abraded and pretreated using a resin primer containing methyl-methacrylate to successfully bond to the luting composite. The pretreatment of the CAD/CAM resin composite using merely a silane primer results in deficient adhesion.

Clinical relevance: For a reliable bond of CAD/CAM resin composites to the luting composite, air abrasion and a special pretreatment strategy are necessary in order to achieve promising long-term results.

Keywords: Air abrasion; CAD/CAM; Failure type; Resin composite; Tensile bond strengths.

Publication types

  • Comparative Study

MeSH terms

  • Air Abrasion, Dental*
  • Composite Resins
  • Computer-Aided Design
  • Dental Bonding / methods*
  • Dental Stress Analysis
  • Materials Testing
  • Methacrylates
  • Resin Cements / chemistry*
  • Shear Strength
  • Surface Properties
  • Tensile Strength

Substances

  • Clearfil Ceramic Primer
  • Composite Resins
  • Methacrylates
  • One Coat Bond
  • Resin Cements
  • Brilliant Dentin resin