Ultrastructural changes in the cemento-enamel junction caused by acidic beverages: An in vitro study.

The present in vitro study was aimed at evaluating the morphological changes in the cemento-enamel junction (CEJ) after exposure to acidic beverages using the scanning electron microscopy (SEM). The initial pH and titratable acidity (TA) was analyzed from follow groups: (I) Coca cola, (II) orange juice, (III) Cedevita, (IV) Red Bull, (V) Somersby cider, and (VI) white wine. The CEJ samples (n = 64), obtained from unerupted third molars, were allocated to one control (artificial saliva, n = 16) and six experimental groups (n = 8). The experimental samples were immersed in beverages (50 ml) for 15 min, three times daily, 10 days, and in artificial saliva between immersions. SEM analysis was performed in a blind manner, according to scoring scale. One-way ANOVA and Tukey's post hoc tests, as well as Kruskal-Wallis and Mann-Whitney U test used for statistical analysis. The pH values of the acidic beverages ranged from 2.65 (Coca cola) to 3.73 (orange juice), and TA ranged from 1.90 ml (Coca cola) to 5.70 ml (orange juice) of NaOH to reach pH 7.0. The SEM analysis indicated statistically significant differences between the control samples and those immersed in acidic beverages. The Groups IV, I, and II, showed the highest CEJ damage grade while those of the Group VI were the lowest. All the tested acidic beverages caused morphological changes in the CEJ with a smaller or larger exposure of dentine surface, and were not always related to the pH or TA of acidic beverages.

Ion-modified nanoparticles induce different apatite formation in cervical dentine.

AIM: To investigate if crystallinity and ultrastructure are modified when cervical dentine is treated with four different nanogels-based solutions for remineralizing purposes. METHODOLOGY: Experimental nanogels based on polymeric nanoparticles (NPs) and zinc, calcium or doxycycline-loaded NPs were applied to citric acid etched dentine to facilitate the occlusion of tubules and the mineralization of the dentine surface. Dentine surfaces were studied by X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging. RESULTS: Crystals at the dentine surface were identified as hydroxyapatite with the highest crystallographic maturity and crystallite size in dentine treated with Zn-NPs-based gel. Texture increased in all samples from 24 h to 7 days, except in dentine surfaces treated with Zn-NPs gel. Polyhedral, plate-like and drop-like shaped apatite crystals constituted the bulk of minerals in dentine treated with Zn-NPs gel, after 7 days. Polymorphic, cubic and needle-like shaped crystals distinguished minerals, with more amorphous characteristics in dentine treated with Ca-NPs gel after 7 days than that found when Zn-NPs were applied. Doxycycline-NPs produced the smallest crystallites with poor crystallinity, maturity and chemical stability. CONCLUSIONS: Crystalline and amorphous phases of newly formed hydroxyapatite were described in both types of dentine treated with Zn-NPs as well as Ca-NPs gels with multiple shapes of crystallites. Crystal shapes ranged from rounded/drop-like or plate-like crystals to needle-like or polyhedral and cubic apatite appearance.

Low-Intensity Ultrasound Combined with Hematoporphyrin Monomethyl Ether in the Treatment of Experimental Periodontitis in Rats.

Objectives. This study aims to evaluate the efficacy of hematoporphyrin monomethyl ether- (HMME-) mediated sonodynamic therapy (SDT) on experimental periodontal disease in rats. Methods. Periodontal disease was induced by submerging ligatures at the first maxillary molar subgingival region in forty-eight male SD rats. After 30 days, the ligatures were removed. The rats were randomly allocated into four groups; the experimental SDT group was treated through hypodermic injection of 40 µg/mL HMME and 3 W/cm2 low-intensity ultrasound irradiation (1 MHz, 600 s). Those in control groups received 40 µg/mL HMME alone (control 1 group) or 3 W/cm2 ultrasound irradiation alone (control 2 group) or were subjected to neither HMME nor ultrasound (control 3 group). After 10 days of treatment, all rats were euthanized, the maxilla was obtained for histological examination, and the alveolar bone level was evaluated by histometric analysis. Results. The control groups showed more bone loss (P < 0.05) after 10 days of treatment than the SDT group. There is no significant difference among the control groups (P > 0.05). Conclusions. HMME mediated SDT was an effective therapy of experimental periodontal tissue in rats.

Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials.

Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA), mineral trioxide aggregate (MTA), and EndoSequence® Root Repair Material (ERRM). Material and Methods. 40 teeth, simulated to average root length of 13 ± 1 mm (Cvek's stage 3), were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P), Group 3: MTA-Angelus (MTA-A), and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers' instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD) failure loads (MPa) were 20.46 ± 2.53 for BA, 18.88 ± 5.13 for MTA-P, 14.12 ± 1.99 for MTA-A, and 17.65 ± 4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p < 0.001), MTA-P and MTA-A (p < 0.05), and ERRM and MTA-A (p < 0.05). Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested.

Prevalence and risk factors of non-carious cervical lesions related to occupational exposure to acid mists.

This study evaluates the prevalence and risk factors of non-carious cervical lesions (NCCLs) in a Brazilian population of workers exposed and non-exposed to acid mists and chemical products. One hundred workers (46 exposed and 54 non-exposed) were evaluated in a Centro de Referência em Saúde do Trabalhador - CEREST (Worker's Health Reference Center). The workers responded to questionnaires regarding their personal information and about alcohol consumption and tobacco use. A clinical examination was conducted to evaluate the presence of NCCLs, according to WHO parameters. Statistical analyses were performed by unconditional logistic regression and multiple linear regression, with the critical level of p < 0.05. NCCLs were significantly associated with age groups (18-34, 35-44, 45-68 years). The unconditional logistic regression showed that the presence of NCCLs was better explained by age group (OR = 4.04; CI 95% 1.77-9.22) and occupational exposure to acid mists and chemical products (OR = 3.84; CI 95% 1.10-13.49), whereas the linear multiple regression revealed that NCCLs were better explained by years of smoking (p = 0.01) and age group (p = 0.04). The prevalence of NCCLs in the study population was particularly high (76.84%), and the risk factors for NCCLs were age, exposure to acid mists and smoking habit. Controlling risk factors through preventive and educative measures, allied to the use of personal protective equipment to prevent the occupational exposure to acid mists, may contribute to minimizing the prevalence of NCCLs.

External cervical resorption associated with the use of bisphosphonates: a case series.

Although the pathogenesis and etiology of external cervical resorption (ECR) are not well understood, several predisposing factors have been reported to potentially contribute toward the initiation of ECR. However, a potential link between systemic medication and ECR has not been reported. Bisphosphonates (BSPs) are 1 group of these medications (the amino-containing BSP), which are associated with an acute-phase response and the release of proinflammatory cytokines, which could be associated with the initiation of ECR. Therefore, a possible causal link between BSPs and ECR could be drawn.

Two-year clinical evaluation of chlorhexidine incorporation in two-step self-etch adhesive.

OBJECTIVES: The aim of this 24-month double-blind randomized paired-tooth clinical study was to evaluate the 2-year clinical performance of two self-etch adhesives containing or not chlorhexidine digluconate (CHX) in non-carious cervical lesions (NCCLs). METHODS: Twenty-two patients, with at least four NCCLs, participated in this study. After sample size calculation, 126 restorations were assigned to one of the following groups: CSE--Clearfil SE Bond (Kuraray); CSE/CHX--Clearfil SE Bond+CHX; ADS--AdheSE (Ivoclar Vivadent); and ADS/CHX--AdheSE+CHX. The composite resin Filtek Z-250 composite (3M ESPE) was placed incrementally by one expert operator. The restorations were evaluated at baseline and after 2 years using the modified USPHS criteria. Statistical analyses were performed with Friedman repeated measures ANOVA by rank and Fisher exact test for significance in each pair (α=0.05). RESULTS: No significant difference was observed between baseline and 2-year for any criteria when adhesives with and without the addition of CHX were compared (p>0.05). ADS and ADS/CHX resulted in lower retention rates (82% on average) than CSE and CSE/CHX (97%) (p=0.02). CONCLUSIONS: The inclusion of CHX into the primer of both self-etch systems did not add clinical advantages over the 2-year period. Clearfil SE Bond resulted in better retention rate than AdheSE. CLINICAL SIGNIFICANCE: It is more important to choose a gold standard self-etch adhesive, like a Clearfil SE Bond, than to consider the inclusion of CHX in the self-etch adhesives.

Prevalence and risk factors of non-carious cervical lesions related to occupational exposure to acid mists

This study evaluates the prevalence and risk factors of non-carious cervical lesions (NCCLs) in a Brazilian population of workers exposed and non-exposed to acid mists and chemical products. One hundred workers (46 exposed and 54 non-exposed) were evaluated in a Centro de Referência em Saúde do Trabalhador – CEREST (Worker’s Health Reference Center). The workers responded to questionnaires regarding their personal information and about alcohol consumption and tobacco use. A clinical examination was conducted to evaluate the presence of NCCLs, according to WHO parameters. Statistical analyses were performed by unconditional logistic regression and multiple linear regression, with the critical level of p < 0.05. NCCLs were significantly associated with age groups (18-34, 35-44, 45-68 years). The unconditional logistic regression showed that the presence of NCCLs was better explained by age group (OR = 4.04; CI 95% 1.77-9.22) and occupational exposure to acid mists and chemical products (OR = 3.84; CI 95% 1.10-13.49), whereas the linear multiple regression revealed that NCCLs were better explained by years of smoking (p = 0.01) and age group (p = 0.04). The prevalence of NCCLs in the study population was particularly high (76.84%), and the risk factors for NCCLs were age, exposure to acid mists and smoking habit. Controlling risk factors through preventive and educative measures, allied to the use of personal protective equipment to prevent the occupational exposure to acid mists, may contribute to minimizing the prevalence of NCCLs.

Effect of corticosteroids on orthodontic tooth movement in a rabbit model.

INTRODUCTION: While there are a growing number of studies on the effects of medications on orthodontic tooth movement (OTM), only few studies have investigated the role of corticosteroids, despite their widespread use. The aim of the current study was to evaluate the effects of triamcinolone acetonide injection on OTM in a rabbit model. STUDY DESIGN: Sixteen one-month old rabbits were randomly divided into two groups: Eight rabbits had triamcinolone acetonide (1 mg/kg/day) administered IM daily for 21 days (test group) while the remaining eight rabbits received no drug (control group). The rabbits in both groups had a tube bonded to the upper central incisors and a stainless steel helical spring was inserted in tube slot to apply 50 cN distal force. After 3 weeks, the rabbits were sacrificed and the distance between mesial corners of incisors was measured The incisors are associated tissue was processed for histology and the apical and cervical area of the roots evaluated. An observer who was blind to the study groups evaluated the specimens. RESULTS: All appliance-treated incisors in test and control groups showed evidence of tooth movement. The distance between the incisors was significantly greater in the triamcinolone acetonide treated group compared to the control group (P < 0.001). Histological examination revealed an increased number of resorption lacunae and decreased number of cuboidal osteoblastic cells around the apical and cervical area of the Incisor roots in the test compared to the control group (P < 0.01). CONCLUSION: Treatment with triamcinolone acetonide is associated with increased tooth movement in rabbits via increased resorptive activity in the alveolar bone.

A randomized double-blind placebo-controlled study of the efficacy of Clinpro XT varnish and Gluma dentin desensitizer on dentin hypersensitivity.

PURPOSE: To evaluate the effect of Clinpro XT Varnish (VXT) paste-liquid, resin-modified glass-ionomer and the resinous dentin desensitizing varnish and Gluma Dentin Desensitizer (Gluma) in treating dentin hypersensitivity (DH). METHODS: This short-term (4-week) randomized, double-blind, placebo-controlled, split-mouth study included a total of 119 teeth from 31 individuals which were randomized into three groups: VXT, Gluma, and placebo (warm water). Dentin sensitivity was evaluated by subjects' perception of DH determined by pretreatment tooth sensitivity score (TSS) measured on a 0-10 visual analogue scale (VAS) after tactile (probe) or thermal/evaporative (blast of air) stimuli. TSS was scored at baseline, immediately after treatment (Day 0), after 1 week and after 4 weeks. RESULTS: For both stimuli, mean TSS was significantly decreased in the VXT and Gluma groups at all time points (all, P < 0.001) compared with baseline. Regarding comparisons of TSS between treatment groups, the VXT group had significantly lower mean TSS compared with the Gluma group (P< 0.05) and placebo control group (P< 0.05) at all time points after treatment regardless of stimuli. Group Effect, Time Effect, and Group x Time Effect were all significantly different (all, P < 0.001).

Five-year clinical performance of the dentine deproteinization technique in non-carious cervical lesions.

OBJECTIVE: The aim of this study was to evaluate the 5-year clinical performance of composite restorations of non-carious cervical lesions (NCCL) using a total-etch adhesive system with or without collagen removal with 10% sodium hypochlorite (NaOCl). METHODS: In this study randomized controlled split-mouth clinical trial, one-hundred and thirty-eight NCCL were restored into 30 patients. Each patient received at least one pair of composite restorations (Filtek A110/3M ESPE), bonded either with 2 techniques: Conventional Technique--acid etching with 37% phosphoric acid+Prime & Bond NT (Denstply DeTrey); Deproteinization Technique--acid etching with 37% phosphoric acid+10% NaOCl for 1min+Prime & Bond NT. The two techniques were evaluated using the United States Public Health Service (USPHS) criteria at baseline, 18 months, 3 and 5 years. After five years, one-hundred and six restorations were evaluated in 24 patients. Data were analyzed using the Chi-Square test (p<0.05). RESULTS: There were no statistically significant differences between the two techniques regarding the evaluated parameters (p>0.05). CONCLUSION: After 5 years, the application of 10% NaOCl deproteinization on etched dentine did not affect the clinical performance of composite restorations placed in NCCL when compared to the conventional total-etch technique. CLINICAL SIGNIFICANCE: Clinical studies evaluating the performance of the Deproteinization Technique are scarce. In this study, this technique showed similar clinical performance at the end of 5 years when compared to a conventional total-etch technique.

Microleakage of nanofilled resin-modified glass-ionomer/silorane- or methacrylate-based composite sandwich Class II restoration: effect of simultaneous bonding.

OBJECTIVES: Microleakage of composite restorations at the cervical margin placed apically to the cementoenamel junction (CEJ) is still a concern. This study evaluated the effect of simultaneous bonding application on cervical sealing of nano-ionomer/silorane- or methacrylate-based composite open sandwich Class II restorations in the modified technique compared with that of conventional bonding. METHODS AND MATERIALS: In 60 sound maxillary premolars, two standardized Class II cavities were prepared with cervical margins 1 mm below the CEJ. The teeth were randomly divided into six groups of 10 teeth each. In the first three groups (groups 1-3), Clearfil SE Bond and Clearfil APX (Kuraray) were used for restoration in the total bonding technique (group 1), conventional open sandwich technique associated with a nano-ionomer (Ketac N100, 3M ESPE) (group 2), and modified open sandwich technique with simultaneous bonding application for both nano-ionomer and composite (group 3). In the second three groups (groups 4-6), Silorane Adhesive and Filtek Silorane composite (3M ESPE) were used in the same manner as in the first three groups, respectively. RESULTS: The simultaneous bonding application in the modified sandwich restorations (with SE Bond or Silorane Adhesive) resulted in a significant reduction of the cervical microleakage compared with that of the conventional bonding (p<0.05). However, microleakage of the modified technique was similar to that of the total bonding (with SE Bond or Silorane Adhesive) (p>0.05), both showing good marginal seal.

Cimetidine reduces alveolar bone loss in induced periodontitis in rat molars.

BACKGROUND: There is evidence that histamine released during inflammation plays a role in bone metabolism via the H2 receptor, stimulating bone resorption. The purpose of this study is to evaluate whether cimetidine, a histamine H2-receptor antagonist, interferes with the initiation and progression of induced periodontal disease in rat molars. METHODS: Forty male rats received 100 mg/kg body weight of cimetidine (cimetidine group [CimG]) or saline solution (sham group [SG]). Periodontal disease was induced in the maxillary left first molars (PDSG and PDCimG); maxillary right molars were used as non-ligature controls. After 7, 15, 30, and 50 days, maxillary fragments were embedded in paraffin. The sections were stained with Masson trichrome and hematoxylin and eosin and subjected to the tartrate-resistant acid phosphatase (TRAP) method. The distances between the cemento-enamel junction (CEJ) and alveolar process (AP) crest, as well as between the CEJ and junctional epithelium (JE) level, were measured; the number of inflammatory cells was computed. Receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) immunohistochemistry was carried out, and the RANKL/OPG ratio was calculated. RESULTS: In PDSG and PDCimG, a significant increase (P ≤0.05) was observed in CEJ-AP and CEJ-JE distances. However, the increases in both distances were significantly less in PDCimG compared with PDSG at 15, 30, and 50 days. Numerous TRAP-positive osteoclasts were found in the PDSG and PDCimG. In PDCimG, the volume density of inflammatory cells and the RANKL/OPG ratio were significantly lower (P ≤0.05) than in PDSG. CONCLUSIONS: Cimetidine exerts a beneficial effect on periodontal disease in rats, decreasing the RANKL/OPG ratio in gingival connective tissue and reducing alveolar bone resorption.

Clarifications, guidelines and questions about the dental bleaching "associated" with orthodontic treatment.

With regard to the best moment for carrying out or recommending dental bleaching to orthodontic patients, some explanations and orientations are given in order to answers the following questions: 1) Why orthodontic treatment completion is considered the best opportunity for carrying out the procedure? 2) Why dental bleaching should not be performed immediately before orthodontic treatment? 3) If that would be possible at any special case, what would that be? 4) Why dental bleaching should not be performed during orthodontic treatment? 5) If that would be possible at any special case, what would that be? This article highlights why it is essential to protect both the mucosa and the cervical region, regardless of the moment when dental bleaching is performed, whether associated with orthodontic treatment or not. The "how", "why" and "if" it is or not convenient to perform dental bleaching before orthodontic treatment are still a matter of clinical suggestion, as it is a procedure that is under analysis, empirical knowledge waiting for scientific proof or disproof! Although tooth enamel has adamantine fluid flowing within it, providing a specific metabolism that is peculiar to its own and which could scientifically explain and base the option of carrying out teeth whitening before and during orthodontic treatment, we must still be very careful.

Clarifications, guidelines and questions about the dental bleaching "associated" with orthodontic treatment

With regard to the best moment for carrying out or recommending dental bleaching to orthodontic patients, some explanations and orientations are given in order to answers the following questions: 1) Why orthodontic treatment completion is considered the best opportunity for carrying out the procedure? 2) Why dental bleaching should not be performed immediately before orthodontic treatment? 3) If that would be possible at any special case, what would that be? 4) Why dental bleaching should not be performed during orthodontic treatment? 5) If that would be possible at any special case, what would that be? This article highlights why it is essential to protect both the mucosa and the cervical region, regardless of the moment when dental bleaching is performed, whether associated with orthodontic treatment or not. The "how", "why" and "if" of whether or not it is convenient to perform dental bleaching before orthodontic treatment are still a matter of clinical suggestion, as it is a procedure that is under analysis, empirical knowledge waiting for scientific proof or disproof! Although tooth enamel has adamantine fluid flowing within it, providing a specific metabolism that is peculiar to its own and which could scientifically explain and base the option of carrying out teeth whitening before and during orthodontic treatment, we must still be very careful.

Quanto ao melhor momento para se aplicar ou recomendar a clareação dentária aos pacientes ortodônticos, alguns esclarecimentos e orientações são explanados para responder questionamentos como: 1) Por que depois do tratamento ortodôntico se constitui a melhor oportunidade para tal procedimento?; 2) Por que não realizar a clareação dentária imediatamente antes do tratamento ortodôntico?; 3) Se poderia realizá-la em alguma condição especial, e qual seria?; 4) Por que não se deveria clarear os dentes durante o tratamento ortodôntico?; 5) Se possível em algumas situações especiais, quando seriam essas situações especiais? No presente artigo, se destacará porque é fundamental sempre proteger a mucosa e a região cervical, independentemente do momento em que se fizer uma clareação dentária relacionada ou não ao tratamento ortodôntico. O mecanismo de como, por que e se é ou não conveniente clarear os dentes antes da finalização dos tratamentos ortodônticos ainda representa uma sugestão clínica, um procedimento em análise e um conhecimento empírico à espera de sua comprovação ou desmitificação científica. Apesar do esmalte dentário ter uma circulação do líquido adamantino, que propicia um metabolismo próprio e específico, que pode vir a ser, cientificamente, a base para explicar e fundamentar a clareação dentária antes e durante o tratamento ortodôntico, ainda assim devemos ser muito cautelosos.

Effects of cyclic fatigue stress-biocorrosion on noncarious cervical lesions.

PROBLEM: Although there is a high prevalence of noncarious cervical lesions (NCCLs), the etiology of these lesions remains contentious. PURPOSE: To evaluate the combined effects of cyclic fatigue stress and biocorrosion activity on NCCLs. MATERIALS AND METHODS: Extracted premolar teeth were allocated into four groups (N = 10). Two groups were cyclically fatigue loaded (100 N; 72 cycles per minute; 9,200 cycles) and placed in either hydrochloric acid gel (pH = 0.1) or orange juice (pH = 4). The other two groups were stored in identical chemical solutions without fatigue load. The buccal-lingual width of each tooth was measured before and after testing. The depth of biocorrosion, normalized by the percentage change in buccolingual width, normalized by time (hour) was calculated. The data were analyzed using a two-way analysis of variance and Tukey's HSD multiple comparison test (α = 0.05). RESULTS: Mean (SD) of the depth of biocorrosion values were as follows: teeth receiving fatigue loading with hydrochloric acid gel exposure (1.003%/hour [0.063]) revealed a significantly higher depth of biocorrosion than the fatigue-loaded group with orange juice exposure (0.511%/hour [0.281]) (p < 0.01). For the groups without fatigue loading, those with hydrochloric acid gel (0.022%/hour [0.006]) had a significantly higher depth of biocorrosion than the group with orange juice (0.009%/hour [0.004]) (p < 0.01). The cyclically fatigue-loaded teeth with hydrochloric acid gel had a significantly greater depth of biocorrosion than either group without fatigue loading (p < 0.001). CONCLUSIONS: Cyclic fatigue stress-acidic biocorrosion had a significant effect on the depth of the NCCLs. CLINICAL SIGNIFICANCE: In order to manage the destructive NCCLs lesions properly, it is essential to understand the etiology of these lesions. The present study indicated that the combined mechanisms of cyclic fatigue stress and biocorrosion could contribute to the formation of NCCLs.

In vitro remineralization of enamel subsurface lesions and assessment of dentine tubule occlusion from NaF dentifrices with and without calcium.

UNLABELLED: Currently, fluoride is the most effective preventive treatment for remineralization of incipient carious lesions and dentinal hypersensitivity due to wasting disorders. The products containing fluoride, calcium and phosphate are also claim to remineralize early, non-cavitated enamel demineralization. The aim of this study was to investigate and compare the efficacy of two such products, Tooth Mousse and Clinpro tooth crème on remineralization and tubule occluding ability with 5000ppm fluoride-containing toothpaste. MATERIALS AND METHODS: Thirty third molar teeth were placed in demineralizing solution for 5 days such that only a window of 1mm x 5mm was exposed to the environment to produce artificial caries-like lesions and randomly assigned to three groups: Group I, 5000ppm sodium fluoride; Group II, GC MI paste plus and Group III, Clinpro tooth crème. Axial longitudinal sections of 140-160 µm of each tooth which included the artificial carious lesion taken and were photographed under polarized light microscope. The demineralized areas were then quantified with a computerized imaging system. The experimental materials were applied onto the tooth sections as a topical coating and subjected to pH-cycling for 28 days. To evaluate tubule occlusion ability, thirty dentin specimens of 2mm thickness were obtained from cervical third of sound third molars. Specimens were ultrasonicated and etched with 6% citric acid for 2 minutes to simulate the hypersensitive dentin. Specimens were randomly divided into above mentioned three groups (n=10). The test agents were brushed over the specimens with an electric toothbrush, prepared and observed under Scanning Electron Microscope for calculation of the percentage of occluded tubules. RESULTS: Group I showed a significantly greater percentage of remineralization than Group III and Group II. Comparison of the remineralization potential between group II and group III were not significant.In case of dentine hypersensitivity, Group I and group III showed greater percentage of tubule occlusion ability than Group II. Intergroup comparison of the tubule occlusion potential of group I and group III were not significant. INTERPRETATION AND CONCLUSION: Within the limitations of our study, sodium fluoride showed relatively greatest remineralizing and dentinal tubule occlusion property when compared with GC MI paste plus and Clinpro tooth crème.

Effect of andiroba oil on periodontitis in Wistar rats.

PURPOSE: To evaluate the effects of andiroba oil on the periodontitis in rats. METHODS: The periodontitis was induced by the placement of cotton ligatures around the cervix of the second upper molars on fifteen rats, and waiting fifty days. The animals were randomly distributed into three groups: saline group, andiroba oil group and meloxican group, differentiated by substance used in the treatment of periodontitis. The groups received the respective substance by gavage for seven days, after the periodontitis induced. It was analyzed the score of inflammatory cells and the measurement from the cemento-enamel junction to the bone crest. RESULTS: The andiroba oil group (p=0.008) and meloxican group (p=0.0347) show a less score of inflammatory cells than saline group, however there weren't difference between them (p=0.2754). Regarding the analysis of measurement from the cemento-enamel junction to the bone crest, there was no difference between groups studied (p=0.3451). CONCLUSION: Andiroba oil decreased the quantity of inflammatory cells, however, it didn't have an effect on the measurement of alveolar bone loss, like the treatment with Meloxican®.

Effect of andiroba oil on periodontitis in Wistar rats

PURPOSE: To evaluate the effects of andiroba oil on the periodontitis in rats. METHODS: The periodontitis was induced by the placement of cotton ligatures around the cervix of the second upper molars on fifteen rats, and waiting fifty days. The animals were randomly distributed into three groups: saline group, andiroba oil group and meloxican group, differentiated by substance used in the treatment of periodontitis. The groups received the respective substance by gavage for seven days, after the periodontitis induced. It was analyzed the score of inflammatory cells and the measurement from the cemento-enamel junction to the bone crest. RESULTS: The andiroba oil group (p=0.008) and meloxican group (p=0.0347) show a less score of inflammatory cells than saline group, however there weren't difference between them (p=0.2754). Regarding the analysis of measurement from the cemento-enamel junction to the bone crest, there was no difference between groups studied (p=0.3451). CONCLUSION: Andiroba oil decreased the quantity of inflammatory cells, however, it didn't have an effect on the measurement of alveolar bone loss, like the treatment with Meloxican®.

Treatments for hypersensitive noncarious cervical lesions: a Practitioners Engaged in Applied Research and Learning (PEARL) Network randomized clinical effectiveness study.

BACKGROUND: The Practitioners Engaged in Applied Research and Learning (PEARL) Network conducted a three-armed randomized clinical study to determine the comparative effectiveness of three treatments for hypersensitive noncarious cervical lesions (NCCLs): use of a potassium nitrate dentifrice for treatment of hypersensitivity, placement of a resin-based composite restoration and placement of a sealant. METHODS: Seventeen trained practitioner-investigators (P-Is) in the PEARL Network enrolled participants (N = 304) with hypersensitive posterior NCCLs who met enrollment criteria. Participants were assigned to treatments randomly. Evaluations were conducted at baseline and at one, three and six months thereafter. Primary outcomes were the reduction or elimination of hypersensitivity as measured clinically and by means of patient-reported outcomes. RESULTS: Lesion depth and pretreatment sensitivity (mean, 5.3 on a 0- to 10-point scale) were balanced across treatments, as was sleep bruxism (present in 42.2 percent of participants). The six-month participant recall rate was 99 percent. Treatments significantly reduced mean sensitivity (P < .01), with the sealant and restoration groups displaying a significantly higher reduction (P < .01) than did the dentifrice group. The dentifrice group's mean (standard deviation) sensitivity at six months was 2.1 (2.1); those of the sealant and restoration groups were 1.0 (1.6) and 0.8 (1.4), respectively. Patient-reported sensitivity (to cold being most pronounced) paralleled clinical measurements at each evaluation. CONCLUSIONS: Sealing and restoration treatments were effective overall in reducing NCCL hypersensitivity. The potassium nitrate dentifrice reduced sensitivity with increasing effectiveness through six months but not to the degree offered by the other treatments. Practical Implications. Sealant or restoration placement is an effective method of immediately reducing NCCL sensitivity. Although a potassium nitrate dentifrice did reduce sensitivity slowly across six months, at no time was the reduction commensurate with that of sealants or restorations.