The universal bonding system appears to be a promising bonding strategy for the maintenance of bond strength to affected dentin. E-64 did not affect bonding to the dentin in contrast to the use of chlorhexidine, which, when associated with the universal system, did affect the microtensile bond strength for artificial carious dentin.

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This study evaluated the impact of orange juice on the bond strength (BS) of dentin bonding systems (DBSs) to enamel surface after simulation with an in situ/ ex vivo erosive cycling. One hundred and ninety two bovine enamel fragments (4x4x2 mm) were obtained and randomized regarding superficial microhardness and distributed to palatal devices for 8 volunteers, in three phases (one for each DBS), containing 8 blocks, which were, allocated in 4 pairs. Daily, these pairs were subjected extraorally to the following conditions: CONTneither erosive nor abrasive challenge; ERO-erosive challenge only; ABR-abrasive challenge only and ERO + ABR-with erosive and abrasive challenges. Erosive cycles (immersion in orange juice, 3 times/day/5 min/5 days) or/and abrasive challenges (electric toothbrush, 3 times/day/1 min/5 days) were performed. After these cycles, all specimens were restored with the adhesive systems Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) or Clearfil SE Bond (SE), and the composite resin Filtek Z250. After 7 days, sticks (area ≅1 mm 2 ) were obtained and subjected to the microtensile bond strength test (μTBS) at 0.5 mm/min. Data was statistically analyzed by ANOVA and Tukey tests (a=0.05). Failure modes were determined using a digital microscope (40×). DBS was the only statistical significant factor. SE was the unique DBS not affected in any challenge, whereas MP and SB performed according to the scenario. The adhesive and mixed failures were predominant in all groups. Overall performance suggested that BS to enamel after erosive /abrasive challenged by orange juice was not affected and it was material-dependent.

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.5, 3.5, and 5% against recombinant matrix metalloproteinases (MMPs) MMPs-2 and -9 was assessed by zymography. To investigate its remineralization potential, 40 bovine root specimens were obtained and subjected to a demineralization protocol to produce caries-like dentin lesions. After that, dentin surfaces were divided into 3 areas: (1) mineralized (no treatment); (2) demineralized; and (3) demineralized/treated with STMP and submitted to a pH-cycling associated or not with STMP (1.5, 3.5, or 5% STMP, 10 min of treatment). After that, superficial hardness (SH) and cross-sectional hardness (CSH) were determined. Polarized light microscopy (PLM) was used to qualitatively evaluate mineralization within the caries-like lesions. The zymographic analysis showed that STMP solution is a potent inhibitor of the gelatinolytic activity of MMPs-2 and -9 depending on the dose, since the lowest concentration (0.5%) partially inhibited the enzyme activity, while the higher concentrations completely inhibited enzyme activity. Regarding remineralization effect, only 1.5% STMP solution enhanced both the SH and CSH. PLM showed that the area treated with 1.5% STMP presented similar birefringence as mineralized sound dentin. In conclusion, 1.5% STMP solution is effective as an antiproteolytic agent against MMPs and promotes dentin remineralization.

CHX was able to promote beneficial BS after 6 mons, which was not noted for any other tested enzyme inhibitors.

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Patients who undergo radiotherapy for head-and-neck cancer usually present oral complications that impair their quality of life. This clinical case presents the advantage of using a semi-direct technique with bioactive materials to restore compromised posterior teeth by dental professionals who participate as members of the oncology network support team to provide long-lasting treatment in a shorter time. Post-radiotherapy patients presented several oral challenges, including the presence of radiation-induced caries. In addition, the left maxillary second premolar showed unsatisfactory class II restoration. For radiation caries lesions, glass-ionomer cement restorations were performed. For the unsatisfactory class II restorations, semi-direct technique using resin composite was used. Glass ionomer-based restorations offer appropriate marginal adaptation and reduced sensitivity. For the semi-direct restorations, adequate anatomical contour, contact point, and occlusal contact were achieved using relevant clinical parameters. For patients who have had head-and-neck radiotherapy, restoration of affected teeth is relevant for improving their dental function to avoid malnutrition and to recover their quality of life, including esthetics and self-esteem. This semi-direct procedure reduced chairside time, which is beneficial also for the professionals. Using bioactive materials and person-centered care concept, technical and long-term benefits can be achieved.

No abstract