In vitro assessment of dental erosion caused by clear aligners.

The primary objective of this in vitro study was to investigate the erosive potential of enamel under the use of clear aligners (CA), by simulating in vivo conditions experienced by patients who do not remove their CA during the consumption of acidic beverages. In addition, the difference in erosion protection conferred by artificial and human saliva was also evaluated. Sound-extracted human premolars (n = 20) had half of their surfaces protected with acid-resistant nail polish and were randomly distributed into two experimental groups (n = 10): teeth immersed in human saliva or artificial saliva. All teeth had half of their lingual surfaces enclosed by a CA device. The erosive challenges consisted of individual immersion of each sample in citrus acid three times a day, intermediated by immersion in human saliva or artificial saliva for 2 h, during ten days of the erosive protocol. The enamel mineral content was analyzed by high-resolution microtomography. The differential mineral concentration profiles were obtained by subtracting the profile of the mineral concentration of the exposed area and enamel under the CA area from the respective sound area (control). In addition, enamel wear and enamel volume loss were measured. Scanning electron microscopy (SEM) was also performed to analyze the enamel surface. Data were analyzed by two-way ANOVA, followed by the Student-Newman-Keuls test. The enamel wear was higher in teeth immersed in artificial saliva, when compared to human saliva (p < 0.001). The volume loss of the exposed enamel area was lower for tooth immersed in human saliva than in artificial saliva (p < 0.001), during the acid challenge protocol. The use of CA during acid challenges promoted wear and mineral loss of dental enamel, being these changes more pronounced on the enamel surface under the CA. These results open a new path for the development of further studies adopting clinical protocols that promote more accurate responses in the clinical practice during orthodontic treatment.

Gingival fenestration defect treated with gingivectomy and gingivoplasty: A case report with an 8-year follow-up.

INTRODUCTION: Gingival fenestration (GF) is scarcely reported in the literature. We present a unique case of GF defect combined with gingivitis and altered passive eruption (APE). CASE PRESENTATION: An 18-year-old female patient with gingivitis, APE, and GF in the mandibular left central incisor presented for periodontal treatment. The gingival lesion was successfully treated with basic periodontal therapy gingivectomy, and gingivoplasty and resulted in an excellent aesthetic long-term outcome. This case report shows its 8-year clinical follow-up. CONCLUSION: There are no earlier reports dealing with the use of gingivoplasty for the treatment of GF, as it is not the usual therapeutic intervention for these defects. Gingivoplasty proved to be effective in treating GF. Why is this case new information? Available literature on gingival fenestration defects does not describe gingivectomy and gingivoplasty as a treatment of choice. Gingivectomy and gingivoplasty proved to be effective in treating gingival fenestration defects. What are the keys to successful management of this case? Proper diagnosis. What are the primary limitations to success in this case? Gingival fenestration has been defined when the overlying gingiva is denuded, exposing the root to the oral cavity. However, in this case report, only the crown was exposed because the patient had altered passive eruption.

Adjuvant therapy with 1% alendronate gel for experimental periodontitis treatment in rats.

PURPOSE: The aim of this study was to evaluate the effects of locally delivered 1% alendronate (ALN) gel used as an adjunct to non-invasive periodontal therapy. METHODS: Ligature-induced periodontitis was performed in 96 rats. The ligature was tied in the cervical area of the mandibular left first molar. The animals were randomly divided into 4 groups: 1) NT, no treatment; 2) SRP, scaling and root planning; 3) SRP/PLA, SRP followed by filling the periodontal pocket with placebo gel (PLA); and 4) SRP/ALN, SRP followed by filling the periodontal pockets with 1% ALN gel. Histomorphometric (percentage of bone in the furcation region [PBF]) and immunohistochemical (receptor activator of nuclear factor-κB ligand, osteoprotegerin, and tartrate-resistant acid phosphatase) analyses were performed. Data were statistically analyzed, with the threshold of statistical significance set at P≤0.05. RESULTS: The SRP, SRP/PLA, and SRP/ALN groups presented a higher PBF than the NT group (P≤0.01) at 7, 15, and 30 days. The SRP/ALN group presented a higher PBF than the SRP/PLA group in all experimental periods, as well as a higher PBF than the SRP group at 15 and 30 days. No differences were observed in the immunohistochemical analyses (P>0.05 for all). CONCLUSIONS: Locally delivered 1% ALN gel used as an adjunct to SRP enhanced bone regeneration in the furcation region in a rat model of experimental periodontitis.