Effects of Coffea arabica on Streptococcus mutans adherence to dental enamel and dentine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Knowledge on dental trauma and orthodontic tooth movement held by a group of orthodontists

The objective of this work was to assess the knowledge about orthodontic tooth movement and dental trauma held by a group of orthodontists in specific areas of Brazil. For this purpose, 166 questionnaires with 15 objective questions about this subject were distributed. One hundred and five questionnaires were properly filled and collected after 30 days. It was concluded that, except for avulsion, the knowledge on dental injuries held by the professionals interviewed was considered unsatisfactory, and about 40% of them were not acquainted with the recommendations for the orthodontic movement of traumatized teeth.

Disinfection protocols to prevent cross-contamination between dental offices and prosthetic laboratories

Control of cross-contamination between dental offices and prosthetic laboratories is of utmost importance to maintain the health of patients and dental office staff. The purpose of this study was to evaluate disinfection protocols, considering antimicrobial effectiveness and damage to the structures of prostheses. Solutions of 1% sodium hypochlorite, 2% chlorhexidine digluconate, 50% vinegar and sodium perborate were evaluated. Specimens were contaminated in vitro with standardized suspensions of Candida albicans, Streptococcus mutans, Escherichia coli, Staphylococcus aureus and Bacillus subtilis spores. Disinfection by immersion for 10. min was performed. Final counts of microorganisms were obtained using the plating method. Results were statistically compared by Kruskal-Wallis ANOVA and Dunn's test. The surface roughness of 40 specimens was analyzed before and after 10 disinfection cycles, and results were compared statistically using Student's t test. The solution of 50% vinegar was as effective as 1% sodium hypochlorite and 2% chlorhexidine against C. albicans, E. coli and S. mutans. The sodium perborate solution showed the lowest antimicrobial effectiveness. Superficial roughness increased after cycles in 1% sodium hypochlorite (p=0.02). Solutions of 1% sodium hypochlorite, 2% chlorhexidine and 50% vinegar were effective for the disinfection of heat-polymerized acrylic specimens. Sodium hypochlorite increased the superficial roughness. © 2013 King Saud Bin Abdulaziz University for Health Sciences.

Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion

Objective: To analyze the long-term skeletal and dentoalveolar effects and to evaluate treatment timing of Class II treatment with functional appliances followed by fixed appliances.Materials and Methods: A group of 40 patients (22 females and 18 males) with Class II malocclusion consecutively treated either with a Bionator or an Activator followed by fixed appliances was compared with a control group of 20 subjects (9 females and 11 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (mean age 10 years), end of treatment with functional appliances (mean age 12 years), and long-term observation (mean age 18.6 years). The treated sample also was divided into two groups according to skeletal maturity. The early-treatment group was composed of 20 subjects (12 females and 8 males) treated before puberty, while the late-treatment group included 20 subjects (10 females and 10 males) treated at puberty. Statistical comparisons were performed with analysis of variance followed by Tukey's post hoc tests.Results: Significant long-term mandibular changes (Co-Gn) in the treated group (3.6 mm over the controls) were associated with improvements in the skeletal sagittal intermaxillary relationship, overjet, and molar relationship (similar to 3.0-3.5 mm). Treatment during the pubertal peak was able to produce significantly greater increases in total mandibular length (4.3 mm) and mandibular ramus height (3.1 mm) associated with a significant advancement of the bony chin (3.9 mm) when compared with treatment before puberty.Conclusion: Treatment of Class II malocclusion with functional appliances appears to be more effective at puberty. (Angle Orthod. 2013;83:334-340.)

Body mass index, dental caries and sugar intake in 2-5 year-old preschoolers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dental fluorosis and its influence on children’s life

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dental caries and related factors in Brazilian children from fluoridated and non-fluoridated areas

PURPOSE: To compare the caries prevalence, saliva buffering capacity (SBC), oral hygiene (OH), dietary habits, family income (FI) and frequency of visits to a dental office (Do) between Brazilian children living in areas with and without fluoridated public water supply. METHODS: Forty-six 5-7-year-old preschoolers were selected in Itatiba, SP, Brazil; 19 were from a fluoridated area, and 27 were from a non-fluoridated area. The caries index was determined according to the World Health Organization criteria, and the SBC was assessed by titration with hydrochloric acid. The FI, frequency of OH and visits to Do were estimated by questionnaire. The dietary habits were assessed with a diet chart. The differences between the groups were analyzed with Mann-Whitney-U tests (α=0.05). RESULTS: Children from the non-fluoridated area showed significantly higher dmft/DMFT than those from the fluoridated area, but they showed significantly lower SBC, OH frequency and FI. No significant differences were observed between the areas for dietary habits and visits to Do. CONCLUSION: Children from fluoridated areas showed higher salivary buffering capacity, family income and oral hygiene frequency as well as lower caries prevalence, supporting the beneficial effect of fluoride in the tap water for caries prevention.

Effect of different bleaching protocols on dental enamel and composite resin

To evaluate changes in microhardness, roughness and surface morphology of dental enamel and composite resin after different tooth bleaching techniques. Material and Methods: Dental fragments from bovine incisors with composite resin restorations were submitted to different bleaching protocols: G1 – daily 8 hours application of a 10% carbamide peroxide (CP) gel during 21 days; G2: 3 applications of 15 minutes of a 38% hydrogen peroxide (H2O2) gel; G3: 38% H2O2 gel associated to irradiation with LED (470nm) during 6 minutes. The Knoop micro hardness of enamel and composite resin were evaluated at 1, 7, 14 and 21 days for G1, and after 1, 2 and 3 sessions for G2 and G3. The roughness and superficial morphology (atomic force microscopy) were evaluated before and at the end of the bleaching treatment. The data were analyzed by Mann-Whitney and Wilcoxon tests (=5%). Results: Significant reduction on enamel hardness was observed after 2 and 3 sessions for G2 and G3. For composite, the reduction occurred after 21 days for G1, and after 3 sessions for G2 and G3 (p<0.05). Significant reduction on roughness and superficial morphology were observed only for enamel of G1 group (p<0.05). Conclusion: The 10% CP gel promoted only superficial alterations on dental enamel, while the 38% H2O2 gel promoted mineral reduction of this dental tissue. All the bleaching protocols promoted reduction on hardness of composite resin.

Dental mineralization and salivary activity are reduced in offspring of spontaneously hypertensive rats (SHR)

Several pathologies have been diagnosed in children of hypertensive mothers; however, some studies that evaluated the alterations in their oral health are not conclusive. This study analyzed the salivary gland activity and dental mineralization of offsprings of spontaneously hypertensive rats (SHR). Thirty-day-old SHR males and Wistar rats were studied. The salivary flow was evaluated by injection of pilocarpine, the protein concentration and salivary amylase activity, by the Lowry method and kinetic method at 405 nm, respectively. Enamel and dentin mineralization of the mandibular incisors was quantified with aid of the microhardness meter. The results were analyzed by the ANOVA or Student's t test (p<0.05). It was noticed that the salivary flow rate (0.026 mL/min/100 g ± 0.002) and salivary protein concentration (2.26 mg/mL ± 0.14) of SHR offspring were reduced compared to Wistar normotensive offspring (0.036 mL/min/100 g ± 0.003 and 2.91 mg/mL ± 0.27, respectively), yet there was no alteration in amylase activity (SHR: 242.4 U/mL ± 36.9; Wistar: 163.8 U/mL ± 14.1). Microhardness was lower both in enamel (255.8 KHN ± 2.6) and dentin (59.9 KHN ± 0.8) for the SHR teeth compared to the Wistar teeth (enamel: 328.7 KHN ± 3.3 and dentin: 67.1 KHN ± 1.0). These results suggest that the SHR offspring are more susceptible to development of pathologies impairing oral health, once they presented lesser flow and salivary protein concentration and lower dental mineralization.

Diabetes triggers the loss of tooth structure associated to radiographical and histological dental changes and its evolution to progressive pulp and periapical lesions in rats

The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.

Effectiveness of a toothpaste with low fluoride content combined with trimetaphosphate on dental biofilm and enamel demineralization in situ

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hepatitis C infection: challenges in dental management and diagnosis of extrahepatic manifestations

Hepatitis C is associated with autoimmune diseases, hepatocellular carcinoma,and extrahepatic manifestations that, in conjunction, may seriously compromise the patient's quality of life. We herein describe a case of chronic hepatitis C with oral manifestations and discuss some implications for diagnosis and treatment. A 63-year-old woman complaining of spontaneous bleeding of the oral mucosa presented with bilateral asymmetric ulcers surrounded by white papules and striae on the buccal mucosa. Her medical history revealed leucopenia, thrombocytopenia, and skin lesions associated with chronic hepatitis C. Propranolol and ranitidine had recently been prescribed. Lichen planus, lichenoid reaction, and erythema multiforme were considered in the differential diagnosis. Histopathological analysis revealed lymphocytic infiltrate in a lichenoid pattern. The lesions partially healed after 1 week and completely regressed after 6 months, despite the maintenance of all medications; no recurrence was observed. The final diagnosis was oral lichen planus associated with hepatitis C. Chronic hepatitis C may present oral manifestations, which demand adjustments in dental treatment planning. Medication side effects may interfere with the clinical presentation and course of the disease and should be accounted for in the differential diagnosis. The possibility of spontaneous remission of oral lichen planus should always be considered, especially when putative etiological factors of a lichenoid lesion are withdrawn in an attempt to differentiate oral lichen planus from lichenoid lesions. This case emphasizes the importance of recognizing the extrahepatic manifestations of hepatitis C as a cause of increased morbidity.

Epidural anesthesia and postoperatory analgesia with alpha-2 adrenergic agonists and lidocaine for ovariohysterectomy in bitches

The aim of this study was to determine the viability and cardiorespiratory effects of the association of epidural alpha-2 adrenergic agonists and lidocaine for ovariohysterectomy (OH) in bitches. Forty-two bitches were spayed under epidural anesthesia with 2.5 mg/kg body weight (BW) of 1% lidocaine with adrenaline (CON) or in association with 0.25 mg/kg BW of xylazine (XYL), 10 mu g/kg BW of romifidine (ROM), 30 mu g/kg BW of detomidine (DET), 2 mu g/kg BW of dexmedetomidine (DEX), or 5 mu g/kg BW of clonidine (CLO). Heart rate (HR), respiratory rate (f(R)) and arterial pressures were monitored immediately before and every 10 min after the epidural procedure. Blood gas and pH analysis were done before, and at 30 and 60 min after the epidural procedure. Animals were submitted to isoflurane anesthesia if they presented a slightest sign of discomfort during the procedure. Time of sensory epidural block and postoperative analgesia were evaluated. All animals in CON and DEX, 5 animals in ROM and CLO, 4 animals in XYL, and 3 in DET required supplementary isoflurane. All groups, except CLO, showed a decrease in HR. There was an increase in arterial pressures in all groups. Postoperative analgesia lasted the longest in XYL. None of the protocols were totally efficient to perform the complete procedure of OH; however, xylazine provided longer postoperative analgesia than the others.

Relationship between elastic and mechanical properties of dental ceramics and their index of brittleness

The purpose of the study was to verify the effects of a number of materials' parameters (crystalline content; Young's modulus, E; biaxial flexure strength, sigma(i); Vickers hardness, VH; fracture toughness, K-Ic; fracture surface energy, gamma(f); and index of brittleness, B) on the brittleness of dental ceramics. Five commercial dental ceramics with different contents of glass phase and crystalline particles were studied: a vitreous porcelain (VM7/V), a porcelain with 16 vol% leucite particles (d.Sign/D), a glass-ceramic with 29 vol% leucite particles (Empress/E1), a glass-ceramic with 58 vol% lithium-disilicate needle-like particles (Empress 2/E2), and a glass-infiltrated alumina composite with 65 vol% crystals (In-Ceram Alumina/IC). Discs were constructed according to manufacturers' instructions, ground and polished to final dimensions (12 mm x 1.1 mm). Elastic constants were determined by ultrasonic pulse-echo method. sigma(i) was determined by piston-on-3-balls method in inert condition. VH was determined using 19.6 N load and K-Ic was determined by indentation strength method. gamma(f) was calculated from the Griffith-Irwin relation and B by the ratio of HV to K-Ic. IC and E2 showed higher values of sigma(i), E, K-Ic and gamma(f), and lower values of B compared to leucite-based glass-ceramic and porcelains. Positive correlations were observed for sigma(i) versus K-Ic, and K-Ic versus E-1/2, however, E did not show relationship with HV and B. The increase of crystalline phase content is beneficial to decrease the brittleness of dental ceramics by means of both an increase in fracture surface energy and a lowering in index of brittleness. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.

Gastroesophageal reflux, dental erosion, and halitosis in epidemiological surveys: a systematic review

In published studies, it has been suggested that dental wear is associated with gastroesophageal reflux disease (GERD). This systematic review was carried out to evaluate the association of GERD, dental erosion, and halitosis and to compare the indices adopted in epidemiological surveys. The Medline database (until October, 2011) was searched systematically to identify studies evaluating the prevalence of oral alterations, such as dental erosion and halitosis, in patients with GERD symptoms. Two reviewers analyzed all reports and the selected studies were evaluated according to the quality of evidence, using the validated Newcastle–Ottawa Quality Assessment Scale. Full-text copies of a total of 32 publications were obtained in duplicate. Sixteen publications were identified among the citations in the Bibliographic lists of studies that fulfilled the exclusion/inclusion criteria and quality of evidence. The relationship between dental erosion and GERD patients was significant in only seven studies. According to three studies, halitosis could be one of several extraesophageal symptoms or manifestations in GERD patients. In one study, it was found that the mucosa of GERD patients was significantly more acidic in comparison with that of the control group. This systematic review showed that there is a relationship between GERD and oral diseases (dental erosion and halitosis). The epidemiological surveys used different indices to analyze GERD and dental erosion. Further research could investigate the best method for assessing the two diseases.