Novel endodontic sealers induce cell cytotoxicity and apoptosis in a dose-dependent behavior and favorable response in mice subcutaneous tissue.

OBJECTIVES: The objective of the present study is to evaluate the in vitro cytotoxicity and in vivo biocompatibility of two novel endodontic sealers: RealSeal XT1 and Sealapex Xpress on the subcutaneous connective tissue of mice. MATERIALS AND METHODS: The cytotoxicity was assessed by cell viability using the MTT assay (one-way ANOVA), trypan blue test (Mann-Whitney) and cell apoptosis by flow cytometer. For the subcutaneous study, polyethylene tubes filled with the sealers were implanted in 70 BALB/c mice: 6 experimental groups (n = 10/group) and 2 control groups with empty tubes (n = 5/group). At the end of experimental periods (7, 21, and 63 days), the tissue was removed and histotechnically processed. Angioblastic proliferation and edema (Fisher's exact test) were evaluated, besides thickness measurement (µm) of the reactionary granulomatous tissue and neutrophil counts (Kruskal-Wallis and Dunn's post test; Mann-Whitney) (α = 0.05). RESULTS: MTT assay, trypan blue, and analysis of apoptotic cells showed a dose-dependent direct effect: the more diluted the sealer, the less cytotoxic. Regarding the angioblastic proliferation and edema, difference between the sealers at 7 and 63 days occurred (p < 0.05). Both endodontic sealers initially promoted perimaterial tissue reaction as a foreign body granuloma and thus stimulated favorable tissue responses. CONCLUSIONS: Both sealers showed a dose-dependent effect and promoted satisfactory subcutaneous tissue response; the sealer Sealapex Xpress was less cytotoxic and more biocompatible than RealSeal XT. CLINICAL RELEVANCE: The step of root canal filling during endodontic treatment is highly important for the preservation of the periapical tissue integrity. Subcutaneous reaction to endodontic sealers enables scientific basis for clinical use.

Dental Flossing and Proximal Caries in the Primary Dentition: A Systematic Review.

PURPOSE: To evaluate in a systematic review whether the use of dental floss in primary teeth is associated with a reduction in incidence of proximal caries. MATERIALS AND METHODS: Searches were performed using the following databases: PubMed MEDLINE, Web of Science, Bireme, Scopus and The Cochrane Library. Only 5 studies were eligible for inclusion. The quality assessment and bias control of the studies were carried out based on the Fowkes and Fulton Guideline. The study concept was first registered in the international prospective register of systematic reviews (PROSPERO). RESULTS: Flossing was professionally performed in one study and self-reported (by parents or by the children) through questionnaires in all other 4 studies. In the first study, the authors concluded that daily interdental flossing resulted in a significant reduction in the incidence of proximal caries in deciduous teeth during a 20-month period. Two cross-sectional studies found that the use of interdental floss did not show any relevant association with the prevalence of caries; one study found that a higher the frequency of flossing was associated with higher caries experience, and the other found an association between severe caries and the use of dental floss, independently of the flossing frequency. CONCLUSION: There is only one study in the current literature showing evidence of an association between the use of dental floss and proximal caries reduction on primary dentition. However, the use of dental floss should never be discouraged. Healthy habits acquired in childhood continue throughout adult life, with numerous oral- and general-health benefits.

Correlation Between Histomorphometric and Micro-computed Tomography Analysis of Periapical Lesions in Mice Model.

Periapical lesions are processes mediated from bacterial invasion on the pulp tissue, which results in inflammatory process and bone resorption. Animal models have been used for the study of cell interactions and inflammatory responses involved in periapical lesion. The use of different methods for morphometric evaluation of this lesion has been reported. However, due to the limitation of 2D methods, computerized microtomography (µCT) has been indicated. Therefore, the aim of this study was to evaluate the correlation between the histomorphometric measures of periapical lesions and the µCT analysis obtained in an animal experimental model. Briefly, the periapical lesions were induced by pulp exposal and after the experimental periods (7, 21 and 42 days) the mice were euthanized. The mandibles were evaluated under the µCT scanning and then were subjected to the routine histologic procedures, stained with hematoxilin and eosin. The periapical lesions were measured by the specific softwares of each technique. A weak correlation among the histomorphometric measurement and the 2D µCT analysis (r(2)= .204) and between the histomorphometric measurement and the 3D µCT analysis (r(2)= .237) was observed. A strong correlation between the 2D and 3D µCT analysis (r(2)= .867) was observed. Thereby, it can be concluded that the µCT is a method that allows a precise volumetric scanning and represents an important tool for morphometric evaluation.

Orthodontic appliances did not increase risk of dental caries and periodontal disease under preventive protocol.

OBJECTIVES: To assess periodontal parameters and microbial species levels after orthodontic appliance placement in patients who received oral hygiene instructions and who were monitored and motivated throughout the study. MATERIALS AND METHODS: The Periodontal Index was recorded and saliva collection was performed before (T0) and 30 (T1), 60 (T2), and 90 (T3) days after orthodontic appliance placement in 15 patients (mean age 17.53 ± 8.0 years). Analysis was carried out using checkerboard DNA-DNA hybridization. Nonparametric statistical analysis was performed. RESULTS: The Periodontal Index did not change. The total amount of the purple and red complexes and Candida species showed a significant decrease from T2. The green, yellow, and orange complex showed a significant decrease at T3. The specific species analysis showed that Prevotella nigrescens, Pseudomonas putida, Fusobacterium periodonticum, Pseudomonas aeruginosa, Peptostreptococcus anaerobius, and Tanerella forsythia showed high incidence before bonding, and their levels decreased at T2 and T3. Only Porphyromonas gingivalis showed increased levels at T2 and displayed the highest level at T3. The Streptococcus group decreased their levels from T2 onward. CONCLUSIONS: A dynamic change in microbial levels was identified. The decrease in the levels of complexes present was only possible due to the mechanical method of oral hygiene implemented in this sample.

Novel endodontic sealers induced satisfactory tissue response in mice.

OBJECTIVES: The aim of this study was to evaluate the subcutaneous response induced by Roeko Guttaflow2 (RG), Sealapex Xpress (SX), AH Plus (AHP) sealers. METHODS: 100 BALB/c mice received implants in the subcutaneous tissue with the tested materials (10 animals per period for each evaluated sealer) and were evaluated after different experimental periods (7, 21 and 63 days), in each animal was placed a tube, the control group was an empty tube. Histological analysis evaluated semi-quantitatively the inflammatory infiltration, collagen fiber formation and tissue thickness. In addition, immunohistochemistry was performed for interleukin-6 (IL-6). Data were statistically analyzed (α = 0.05). RESULTS: RG promoted a greater collagen fiber formation at 7 days and 63 days compared to the CG (p = 0.004) and AHP (p = 0.005) respectively, while at 21 days, the SX promoted a greater reaction (p = 0.021). For the tissue thickness, there was a greater reaction at 7 days with CG (p = 0.0156) and with RG at 63 days (p = 0.03). Regarding the inflammatory infiltrate, there was no difference at 7 days and 63 days (p = 0.5; p = 0.27), while at 21 days, a statistically difference was found between SX, CG (p = 0.04) and RG (p = 0.027). In addition, the presence of IL-6 was observed in almost all groups, with a more intense marking at 7days. SIGNIFICANCE: All cements evaluated presented a satisfactory tissue response, however, RG was the one that presented a more satisfactory tissue response.

Does apical negative pressure prevent the apical extrusion of debris and irrigant compared with conventional irrigation? A systematic review and meta-analysis.

The aim of this study was to evaluate if apical negative pressure (ANP) irrigation prevents the apical extrusion of debris and irrigant compared with conventional needle irrigation through a systematic review and meta-analysis. A computer search of dental literature was performed using four different databases. A combination of the terms 'apical negative pressure', 'endovac', 'apical extrusion', 'extrusion' and 'endodontics' was used. Studies that used extracted human teeth with a mature apex and that evaluated the apical extrusion of debris and/or irrigating solution were included. After an evaluation of the full studies according to the eligibility criteria, eight studies were critically analysed and subjected to quality assessment and risk of bias. Only four studies that evaluated extrusion of irrigant were considered as having high methodological quality and were subjected to a meta-analysis. Studies evaluating extrusion of debris did not have sufficient methodological quality to be subjected to the meta-analysis. The forest plot indicated that ANP irrigation prevents the risk of irrigant extrusion compared with conventional irrigation (OR 0.07 [95%CI 0.02-0.20]; P < 0.00001). This systematic review and meta-analysis showed that ANP prevents the apical extrusion of irrigant. There is no evidence if this type of irrigation prevents the extrusion of debris.

Clinical findings, dental treatment, and improvement in quality of life for a child with Rothmund-Thomson syndrome.

The purpose of this study was to report the clinical findings, dental treatment, and improvement in quality of life for a child with Rothmund-Thomson syndrome. The patient had alopecia, delayed speech, low weight and height, cholestasis, and iron deficiency anemia. Furthermore, there were carious lesions and darkened spots on all primary molars. Microdontia of a premolar was observed at the radiographic examination. The patient and family had no commitment to her oral health and dental treatment at first appointments. Oral hygiene instructions, composite restorations, endodontic treatments, teeth extractions, and stainless steel crown installations were performed. The patient was followed up for 7 years through the present due to other possible future clinical findings associated with the syndrome. An improvement in social aspects was observed after removal of toothache and improved esthetics. Such patients need continuous periodic services, which contributes to improving the quality of life in both buccal and general aspects.