Bonding Capacity of a Universal Adhesive in Different Etching Modes to Caries Affected Dentin Prepared by Two Caries Excavation Techniques | ||||
| Egyptian Dental Journal | ||||
| Article 23, Volume 64, Issue 4 - October (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics), October 2018, Page 3747-3759 PDF (822.92 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/edj.2018.79347 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Nadia M. Zaghloul | ||||
| Assistant Professor, Department of Operative Dentistry, Faculty of Dentistry, Mansoura University. | ||||
| Abstract | ||||
| Objectives: The aim of the present study was to evaluate and compare the microtensile bond strength (μTBS) and resin penetration into caries affected dentin (CAD), of a universal adhesives applied into two different etching modes (i.e. self-etch or etch-and-rinse), after caries excavation with two methods, Round tungsten carbid bur CB or Carisolv chemomecanical caries removal (CMCR). Materials and Methods: Fourty human third molar teeth with moderate occlusal carious lesions were collected. The selected teeth were cut parallel to the occlusal surface of the tooth to expose the carious lesion. Teeth were divided into two groups (n=20) relative to the caries excavation methods i.e. Group1: Carisolv CMCR and group 2: round (CB). Each group was subdivided into two subgroups (n=10) relative to the applied adhesive mode i.e. subgroup a: the adhesive system was applied in a self-etch mode (SE), while in subgroup b: the adhesive system was used in the etch & rinse mode (E & R). Following the application of the adhesive, Filtek Z350 XT resin composite was applied incrementally onto the CAD. The bonded specimens were thermocycled for 5000 cycles. The restored teeth were sectioned longitudinally to obtain bonded beams for μTBS. Beams were mounted into the universal testing machine. Bond strength, for each subgroup, was calculated and statistically analyzed. After debonding the beams, the fracture surfaces were examined under stereomicroscope to detect the failure modes. One beam, from the area of CAD, from each subgroup was selected for SEM examination. Results: Two-way ANOVA indicated high significances for caries excavation and adhesive modes factors (p <.0001). The highest mean value of μTBS was recorded with CMCR , bonded with E & R mode , followed by CB method, bonded with E & R mode, CMCR bonded with SE and CB and bonded with SE adhesive; respectively. Tukey’s test displayed that there is no significant difference in the μTBS between the groups bonded with E & R adhesives, while CB method bonded with SE mode showed significant decrease in the μTBS value (p < 0.05), with all test groups. All the tested groups showed cohesive failure mode in dentin rather than adhesive. In contrast, CB excavation method with SE mode displayed increased adhesive mode of failure rather than the cohesive and mixed modes. Removal of the caries with both methods and bonding with E & R adhesive resulted in relatively thin hybrid layer, but thicker with CMCR, with moderate distribution of resin tags. SE mode of adhesion showed a relatively thick hybrid layer with short conical shaped resin tags. The dentinal tubules were at most occluded with smear blugs and calcfic precipitates. Conclusions: Based on the limitation of this study, the results showed that the use of Carisolv CMCR does improve the μTBS of universal adhesives to CAD, either in SE or E & R modes. | ||||
| Keywords | ||||
| micro-tensile bond strength; caries excavation techniques; universal adhesives | ||||
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