The aim of this study was to evaluate the effect of pH on the activation of matrix metalloproteinases (MMPs) of human coronal (CD) and radicular dentin (RD). CD and RD were pulverized to powder, and proteins were extracted with 1% phosphoric acid. The extracted proteins and the demineralized powder were separately incubated in the following solutions: 4-aminophenylmercuric acetate (control) or a buffer solution at different pHs (2.5, 4.5, 5.0, 6.0, and 7.0). After incubation, proteins were separated by electrophoresis to measure MMP activities by zymography. To assess the solubilized dentin collagen, the demineralized dentin powder was sustained in incubation buffer, and the amount of hydroxyproline (HYP) released was measured. Zymography revealed MMP-2 gelatinolytic activities for CD and RD in all experimental groups. For both substrates, the lowest pH solutions (2.5, 4.5, and 5.0) yielded higher gelatinolytic activity than those obtained by the highest pH solutions (6.0 and 7.0). For HYP analysis, no detectable absorbance values were observed for pHs of 2.5 and 4.5. The amount of HYP was higher for pH 7.0 than those of all other groups (p < 0.05), except for pH 6.0. No statistical differences were found between pHs 6.0 and 5.0 and control (p > 0.05). The MMP-2 enzyme from human CD and RD is dynamically influenced by pH: at low pH, the extracted enzyme activates this latent form, whereas collagen degradation by the matrix-bound enzyme is only observed when pHs are close to neutral.

Background: This case report presents the dimensional changes in dental arches in a patient with hypohidrotic ectodermal dysplasia (HED) after complete denture rehabilitation, with an 18-year follow-up period. Case report: The patient had complete anodontia and was successfully rehabilitated with conventional complete dentures at 3, 4, 5, 7, 9, 12, 16, and 21 years of age. Each successive denture was larger and contained more and larger teeth so as to accommodate for the increase in the size of the developing jaw. A series of diagnostic casts were used to measure the dimensional changes in the arch length and width of the alveolar ridge. Cast analysis revealed that there was an increase in arch length and width in both the maxilla and mandible over time. Cephalometric analysis of craniofacial development was performed at 21 years of age, and suggested protrusion of the maxilla and mandible. Conclusions: The absence of teeth due to HED did not affect the dimensional changes in dental arches after complete denture rehabilitation from childhood to adulthood. The prosthetic treatment improved the patient’s social integration and enabled the development of normal dietary habits, speech, and facial esthetics, which in turn led to improved quality of life.

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Objective: This case report proposes a treatment for dentin hypersensitivity (DH) using photobiomodulation (PBT) with low power diode laser. Methods and Results: Male patient, 28 years old, reporting “dental sensitivity,” diagnosed by anamnesis and intraoral examination, with non-carious cervical lesions (NCCL) and DH on teeth 15 to 25, with different pain intensities, measured with visual analogue scale (VAS). For DH treatment, a PBT was proposed, with 808nm, 100mW, 20s and 2J of energy, applied during 3 sessions, with one-week interval and reevaluation after 30 days. After the first session, the patient reported improvement of sensitivity in all teeth, except for 15, that remained sensitive even during the reevaluation. Conclusion: PBT was effective in DH treatment, with desensitization being observed for 30 days in 90% of treated teeth.