New Perspectives on Desensitization in the Current Era - An Overview

Blood group and tissue incompatibilities remain significant barriers to achieving transplantation. Although no patient should be labeled “un-transplantable” due to blood group or tissue incompatibility, all candidates should be provided with individualized and realistic counseling regarding their anticipated wait times for deceased donor or kidney paired donation matching, with early referral to expert centers for desensitization when needed. Vital is the careful selection of patients whose health status is such that desensitizing treatment is less likely to cause serious harm and whose anti-HLA antibody status is such that treatment is likely to accomplish the goal of increasing organ offers with an acceptable final crossmatch. Exciting new developments have re-energized the interest and scope of desensitization in the times ahead.

Characterization of Fluorotic Enamel After Microabrasion and Desensitizing Agent

Introduction. Enamel microabrasion is a procedure used for removing a superficial layer of enamel that has some alteration of color and/or texture caused by dental fluorosis. The purpose of this study was to compare the microhardness and micromorphology of the fluorotic enamel surface after microabrasion with 6.6% hydrochloric acid and silica or 18% hydrochloric acid and evaluate the effect of desensitizing agent exposure on the treated enamel. Materials and Methods. Twenty anterior teeth with moderate fluorosis were divided into two groups: 1) Perla-Dent® group and 2) Opalustre® group. Each buccal surface of incisors was sectioned to obtain samples 3x3 mm. The samples were then mounted in acrylic blocks. The enamel surface of the blocks was polished, after the microabrasion materials and desensitizing agent were applied according to the manufacturer's instructions. All samples were analyzed by Vickers microhardness tester and scanning electron microscopy (SEM). Results. Both experimental groups presented a decrease in the microhardness values, with statistically significant differences (p<0.0001) when comparing the baseline and after treatments values. To compare the microhardness values after both microabrasion and desensitizing treatment in the study groups, it was observed that the Perla-Dent® group obtained lower values than the Opalescence® group with a statistically significant difference (p<0.0001). The representative images of study groups in SEM showed the enamel surface morphology after Perla-Dent® treatment more irregular and a very marked relief than that observed in enamel surface morphology after Opalustre® treatment. Conclusion. The surface of the enamel was more affected with Perla-Dent® treatment than with Opalustre® treatment and the placement of UltraEz® agent does not recover its baseline microhardness.

Characterization of Fluorotic Enamel After Microabrasion and Desensitizing Agent

Introduction. Enamel microabrasion is a procedure used for removing a superficial layer of enamel that has some alteration of color and/or texture caused by dental fluorosis. The purpose of this study was to compare the microhardness and micromorphology of the fluorotic enamel surface after microabrasion with 6.6% hydrochloric acid and silica or 18% hydrochloric acid and evaluate the effect of desensitizing agent exposure on the treated enamel. Materials and Methods. Twenty anterior teeth with moderate fluorosis were divided into two groups: 1) Perla-Dent® group and 2) Opalustre® group. Each buccal surface of incisors was sectioned to obtain samples 3x3 mm. The samples were then mounted in acrylic blocks. The enamel surface of the blocks was polished, after the microabrasion materials and desensitizing agent were applied according to the manufacturer's instructions. All samples were analyzed by Vickers microhardness tester and scanning electron microscopy (SEM). Results. Both experimental groups presented a decrease in the microhardness values, with statistically significant differences (p<0.0001) when comparing the baseline and after treatments values. To compare the microhardness values after both microabrasion and desensitizing treatment in the study groups, it was observed that the Perla-Dent® group obtained lower values than the Opalescence® group with a statistically significant difference (p<0.0001). The representative images of study groups in SEM showed the enamel surface morphology after Perla-Dent® treatment more irregular and a very marked relief than that observed in enamel surface morphology after Opalustre® treatment. Conclusion. The surface of the enamel was more affected with Perla-Dent® treatment than with Opalustre® treatment and the placement of UltraEz® agent does not recover its baseline microhardness.

Properly timed exposure to central ANG II prevents behavioral sensitization and changes in angiotensin receptor expression

Previous studies show that the angiotensin type 1 receptor (AT1R) is susceptible to rapid desensitization, but that more chronic treatments that stimulate ANG II lead to sensitization of several responses. It is unclear, however, if the processes of desensitization and sensitization interact. To test for differences in AT1R expression associated with single or repeated injections of ANG II, we measured AT1R mRNA in nuclei that control fluid intake of rats given ANG II either in a single injection or divided into three injections spaced 20 min apart. Rats given a single injection of ANG II had more AT1R mRNA in the subfornical organ (SFO) and the periventricular tissue surrounding the anteroventral third ventricle (AV3V) than did controls. The effect was not observed, however, when the same cumulative dose of ANG II was divided into multiple injections. Behavioral tests found that single daily injections of ANG II sensitized the dipsogenic response to ANG II, but a daily regimen of four injections did not cause sensitization. Analysis of 125I-Sar1-ANG II binding revealed a paradoxical decrease in binding in the caudal AV3V and dorsal median preoptic nucleus after 5 days of single daily injections of ANG II; however, this effect was absent in rats treated for 5 days with four daily ANG II injections. Taken together, these data suggest that a desensitizing treatment regimen prevents behavior- and receptor-level effects of repeated daily ANG II.

Clinical Evaluation of Desensitizing Treatment for Incisor Teeth Affected by Molar-Incisor Hypomineralization

Background: Sensitivity complaints are commonly observed in teeth affected by MIH (molar incisor hypomineralization). Aim: This study aimed to evaluate the hypersensitivity observed in MIH-affected teeth and the effect of desensitizing agents applied with and without ozone to incisors affected by MIH. Study Design: The first part of the study included 120 teeth from 42 patients with MIH. These 42 patients included 33 children with 92 incisor teeth with a Vas score of ≥30, and these 92 incisors were included in the second part of the study. The patients included in the second part were divided into three main groups and six subgroups. The main groups included the following: fluoride, CPP-ACP and CPP-ACP with fluoride. Each main group was divided into two subgroups: one with ozone use and one without ozone use. Results: Girls exhibited significantly more sensitivity compared with boys (p&lt;0.05). There were significant decreases in hypersensitivity compared to baseline in all of the groups (p&lt;0.05). There were no differences among the groups at the end of the study (p≯0.05). Conclusion: The results of this study revealed that gender is an important factor in the sensitivity of teeth with MIH. Desensitizing agents effectively reduced the hypersensitivity of teeth with MIH. CPP-ACP paste was found to be more effective, and ozone therapy prolonged the effect of CPP-ACP paste.