Prior Restorative Procedures to Endodontic Treatment.

Tooth loss due to fracture and the failure of endodontic treatment (ET) are common situations in teeth with extensive tissue destruction. This is due to the fragility of the remaining dental structure and the difficulty in sealing cavities, which is sometimes associated with the violation of the supracrestal insertion tissue. The previous restoration of marginal ridges or cusps with composite resin (CR) restores their fracture resistance, due to the adhesive characteristics of the restorative material, while also protecting the quality of endodontic treatment through better sealing. However, the protocol adopted in teeth requiring endodontic treatment involves performing the restorative procedure only after the endodontic procedures. The objective of this study was to report a case in which restoration of marginal ridges and/or cusps was performed prior to endodontic treatment, focusing on maintaining the tooth in function without dental fracture. The restoration was performed with an inverted operative sequence before the endodontic treatment. There was a violation of the supracrestal insertion tissue, requiring crown lengthening surgery (CLS) prior to the restorative procedure. Clinical and radiographic evaluations were performed postoperatively at seven days, three, six, and nine months, and five years. Tooth function was maintained without dental fractures or restoration loss. Periradicular space healing occurred with the disappearance of the lesion. Performing the restorative procedure prior to endodontic treatment in teeth with extensive coronal destruction is an alternative technique that facilitates clinical procedures, reduces the likelihood of dental loss due to fracture, and promotes endodontic treatment success.

Enamel-resin bond durability of self-etch and etch & rinse adhesives.

PURPOSE: To evaluate the degradation of resin-enamel interfaces bonded with different adhesive systems. METHODS: Flat enamel surfaces were ground buccally on bovine incisors. Two etch & rinse self-priming adhesives (Single Bond, Prime & Bond NT), three two-step self-etch adhesives (Clearfil SE Bond, Resulcin Aquaprime, NRC/Prime & Bond NT) and two all-in-one adhesives (Etch & Prime 3.0, Adper Prompt-L-Pop) were used for bonding. A hybrid resin composite (Tetric Ceram) was selected for coronal build-up. Bonded specimens were stored in water at 37 degrees C for 24 hours, 6 months and 1 year, respectively, and then sectioned into 1 mm2 beams. Each microtensile stick was loaded in tension until failure (crosshead speed: 0.5 mm/minute). Bond strength data were analyzed with two-way ANOVA and Student Newman Keuls tests (P < 0.05). Etching patterns resulting from phosphoric acid etching and self-etch adhesives application on ground enamel were analyzed under SEM. RESULTS: All adhesives attained similar bond strengths after 24 hours. All-in-one adhesives and Resulcin Aqua Prime recorded a significant reduction in bond strengths after 6 months and 1 year of water aging.

Effect of the hydration status of the smear layer on the wettability and bond strength of a self-etching primer to dentin.

PURPOSE: To evaluate the microtensile bond strength (MTBS) of a resin-based composite to smear layer-covered dentin using a self-etching primer, Clearfil SE Bond (CSEB), under two different hydration states. Surface roughness and wettability (contact angle measurements) of water and the CSEB primer were also evaluated on this substrate. METHODS: Contact angle (CA) measurements were performed on four caries-free extracted human third molars. The specimens were sectioned parallel to the occlusal surface to expose the moderately deep dentin and ground flat (180-grit SiC) under water to provide uniform flat surfaces. In two samples, the smear layer was completely air-dried; in the other two specimens, the smear layer was briefly air-dried. Contact angle measurements were performed to assess wettability of water and CSEB primer using the Axisymmetric Drop Shape Analysis technique. Surface roughness (SR) was determined with a contact profilometer. In another four molars, CSEB was applied to the smear layer-covered dentin with both hydration states. Resin build-ups were performed incrementally with Tetric Ceram. After storage for 24 hours in water at 37 degrees C, the teeth were sectioned to obtain bonded beams with an average cross-sectional area of 1.0 mm2. Each beam was tested in tension in an Instron machine at 0.5 mm/minute. Kolmogorov-Smirnov and Student t-tests were performed at a 95% significance level. RESULTS: Observed water contact angles were lower on the hydrated smear layer but no differences were found between contact angles on completely and briefly air-dried smear layer when the primer was used for CA measurements. SR was similar for both substrates and MTBS was greater when the adhesive was applied on the completely air-dried smear layer.