Dentin Hypersensitivity: Recent Concepts in Management

Tooth sensitivity is a very common clinical presentation which can cause considerable concern for patients. Dentin hypersensitivity (DH) is characterized by short sharp pain arising from exposed dentin in response to stimuli. The most widely accepted theory of how the pain occurs is Brannstrom′s hydrodynamic theory, fluid movement within the dentinal tubules. The condition generally involves the facial surfaces of teeth near the cervical aspect and is very common in premolars and canines. This condition is frequently encountered by dentists, periodontists, hygienists and dental therapists. Some dental professionals lack confidence in treating DH. The management of this condition requires a good understanding of the complexity of the problem, as well as the variety of treatments available. This review considers the etiopathogenesis, incidence, diagnosis, prevention and management of dentinal hypersensitivity. DH is diagnosed after elimination of other possible causes of the pain. Any treatment plan for DH should include identifying and eliminating predisposing etiologic factors. Professionals should appreciate the role causative factors play in localizing and initiating hypersensitive lesions. It is important to identify these factors so that prevention can be included in the treatment plan. Treatments can be self-administered by the patient at home or be applied by a dental professional in the dental office. At-home methods tend to be simple and inexpensive and can treat simultaneously generalized DH affecting many teeth Desensitizing treatment should be delivered systematically, beginning with prevention and at-home treatments. The latter may be supplemented with in-office modalities

A study of alcohol dehydrogenase

The thermostability of pure yeast alcohol dehydrogenase has been investigated at various temperatures (50–70 °C) in the presence and absence of sucrose [0, 44.44%(w/w)] by both activity assay and differential scanning calorimetry. The thermal inactivation exhibited non-linear biphasic behavior. The thermal inactivation rate constants and the magnitude of the heat-stable and heat-labile fractions of the enzyme were quantified. The values of the denaturation temperature (Td) were experimentally measured by differential scanning calorimetry. A Td of 63 °C was obtained for the pure alcohol dehydrogenase in the absence of sucrose. Addition of 44.44%(w/w) sucrose yielded a higher denaturation temperature (70 °C). It was found that although activity assay and calorimetry are based on different principles (kinetic in the former case as opposed to thermodynamic in the latter), they yield results that agree well with each other. These results are discussed in the light of both series and parallel enzyme inactivation model

Thermal stability of alcohol dehydrogenase enzyme determined by activity assay and calorimetry

The thermostability of pure yeast alcohol dehydrogenase was investigated at various temperatures, in the presence and absence of sucrose, by both activity assay and differential scanning calorimetry. The thermal inactivation exhibited nonlinear biphasic behavior. The thermal inactivation rate constants and the magnitude of the heat-stable and heat-labile fractions of the enzyme were quantified. The values of the denaturation temperature were experimentally measured by calorimetry. It was found that although activity assay and calorimetry are based on different principles, they yield results that agree well with each other. However, each technique provides unique data (e.g. enzyme activity vis-a-vis basic thermodynamic properties, such as the denaturation enthalpy) and the two techniques may be considered complementary to each other

Phase 3 RCT comparing docetaxel-platinum with docetaxel-platinum-5FU as neoadjuvant chemotherapy in borderline resectable oral cancer

Background: Neoadjuvant chemotherapy (NACT) with TPF (docetaxel, cisplatin, and 5FU) is one of the treatment options in very locally advanced oral cancer with a survival advantage over PF (cisplatin and 5FU). TP (docetaxel and cisplatin) has shown promising results with a lower rate of adverse events but has never been compared to TPF. Methods: In this phase 3 randomized superiority study, adult patients with borderline resectable locally advanced oral cancers were randomized in a 1:1 fashion to either TP or TPF. After the administration of 2 cycles, patients were evaluated in a multidisciplinary clinic and further treatment was planned. The primary endpoint was overall survival (OS) and secondary endpoints were progression-free survival (PFS) and adverse events. Results: 495 patients were randomized in this study, 248 patients in TP arm and 247 in TPF arm. The 5-year OS was 18.5% (95% CI 13.8–23.7) and 23.9% (95% CI 18.1-30.1) in TP and TPF arms, respectively (Hazard ratio 0.778; 95% CI 0.637–0.952; P = 0.015). Following NACT, 43.8% were deemed resectable, but 34.5% underwent surgery. The 5-year OS was 50.7% (95% CI 41.5–59.1) and 5% (95%CI 2.9–8.1), respectively, in the surgically resected versus unresected cohort post NACT (P &lt; 0.0001). Grade 3 or above adverse events were seen in 97 (39.1%) and 179 (72.5%) patients in the TP and TPF arms, respectively (P &lt; 0.0001). Conclusion: NACT with TPF has a survival benefit over TP in borderline resectable oral cancers, with an increase in toxicity which is manageable. Patients who undergo surgery achieve a relatively good, sustained survival.</p