Influence of Different Types and Concentrations of Chemical Catalysts on Dental Bleaching Efficiency.

The objective of this study was to evaluate the effects of different types and concentrations of chemical catalysts on the efficiency of 35% hydrogen peroxide gel on dental bleaching. Enamel-dentin disks were obtained from bovine incisors and the initial color was assessed. The groups were divided according to the type and concentration of catalyst added to an experimental gel: ferrous sulphate (FS) (0.001, 0.002 and 0.003%); ferrous gluconate (Fg) (0.01, 0.02 and 0.03%); ferric chloride (FC) (0.01, 0.02 and 0.03%); manganese gluconate (MG) (0.01, 0.02 and 0.03%); and manganese chloride (MC) (0.01, 0.02 and 0.03%). The positive control (PC) group received the bleaching gel without any catalyst, while in the negative control (NC) the specimens remained in artificial saliva. Three applications of the bleaching gels were performed for 10 minutes each, repeated after 7 days. Color assessments were performed 7 days after the first session and 7 days after the second. The specimens were stored in artificial saliva and assessed again after 1 year. The data were analyzed by parametric analysis of variance and Tukey's test. Some of the chemical catalysts tested were effective in reducing the yellowish color of the samples in relation to the positive control group after 1 and 2 applications and diminished the color relapse over time. After 1 year, the FS was the most effective catalyst tested. We concluded that some chemical catalysts increased the efficiency of dental bleaching.

Osteoradionecrosis: case report / Osteorradionecrose: relato de caso

Pacientes submetidos à radioterapia como parte do tratamento do câncer de cabeça e pescoço estão sujeitos a desenvolver osteorradionecrose (ORN). As exodontias têm sido implicadas como principal fator desencadeador de ORN, particularmente em região de molares inferiores. A osteorradionecrose tem sido reportada em até 20% dos pacientes irradiados submetidos à exodontia, e é reconhecida como a mais severa complicação da radioterapia em mandíbula, acarretando grande desconforto e perda na qualidade de vida do paciente. O risco de desenvolvimento de ORN é relacionado à dose, técnica e volume de tecido irradiado, e outros fatores predisponentes como: exodontia no período peri-radioterapia, local de extração, doença periodontal preexistente, trauma causado por próteses mal adaptadas, higiene oral deficiente, deficiência nutricional, uso de álcool e fumo, e doenças sistêmicas. A injúria celular e hipóxia causadas por redução do suprimento vascular, reduzem a capacidade de recuperação dos tecidos moles e do osso, predispondo-os a necrose e osteonecrose inclusive espontânea. O manejo clínico da osteorradionecrose, é complexo e dependendo do grau de acometimento pode requerer além de uso de analgésicos e antibioticoterapia a adoção de procedimentos cirúrgicos, tendo como objetivo eliminar a dor, controlar a infecção e evitar ou reduzir a progressão da lesão.O objetivo deste trabalho é relatar um caso de osteorradionecrose atendido na clínica multidisciplinar do Projeto Onco – ICT/ UNESP São José dos Campos.

Patients undergoing radiotherapy alone or as part of the treatment of head and neck cancer are likely to develop osteoradionecrosis (ORN). Dental extractions have been inferred as the main triggering factor of ORN, particularly in mandibular molars. The osteoradionecrosis has been reported in up to 20% of irradiated patients undergoing dental extraction and is recognized as the most severe complication of radiotherapy in the mandible, causing great discomfort and loss of quality of life of patients. The risk of ORN development is related to the dose, technique, and volume of irradiated tissue, and other predisposing factors such as: extraction at peri-radiotherapy period, site of extraction, pre-existing periodontal disease, general trauma, poor oral hygiene, nutritional deficiency, alcohol and smoking, and systemic diseases. The cellular injury and hypoxia caused by decreased blood supply reduce the recoverability of soft tissue and bone, predisposing them to necrosis and osteonecrosis, even spontaneous. Clinical management of osteoradionecrosis is complex and depending on the degree of involvement, it may require analgesics and antibiotics in addition to the adoption of surgical procedures, aiming to eliminate pain, control infection, and prevent orreduce the progression ofthe lesion. This paper aimed to report a case of osteoradionecrosis treated in the multidisciplinary clinic of the Onco Project - ICT/UNESP (São José dos Campos/SP, Brazil). A female patient aged 65 years with osteoradionecrosis and fistula after radiotherapy of squamous cell carcinoma in gingiva was submitted to tooth extraction, antibiotic therapy and local care with good response and flow interruption through the fistula. During the treatment, the carcinoma relapsed and the patient was referred for oncologic treatment.

Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia

A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years) and their matched controls (healthy children). One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 μg glucose/mg biofilm; 7,503±3,097 μg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 μg glucose/mg biofilm; 4,995±682 μg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025), polysaccharides (p=0.025) and proteins (p=0.047) compared with the isolates from control group. However, there was ...

Oral microbial colonization in children with sickle cell anaemia under long-term prophylaxis with penicillin.

BACKGROUND AND OBJECTIVE: Sickle cell anaemia (SCA) is the most frequent haematological hereditary disease. Children with SCA are submitted to long-term prophylactic therapy with penicillin, but little is known about its impact on oral microflora. The aim of this study was to evaluate the oral microbial colonization of paediatric patients with SCA. DESIGN: Forty children (4-11yrs old) with SCA (genotype SS) under long-term prophylactic treatment with penicillin were included in the study. Age/gender-matched control group of healthy children was also included. Scores of dmft/DMFT (number of decayed (D), missing (M), or filled (F) teeth; dmft, for primary dentition; DMFT, for permanent dentition) were obtained and stimulated saliva was sampled. Salivary flow rate and buffering capacity were evaluated. Counts of microorganisms (mutans streptococci, lactobacilli and yeasts) were determined by plating method. Yeasts were identified by API 20C AUX and PCR. RESULTS: Mean dmft/DMFT values were similar in the studied groups (SCA 2.13/1.60 and control 2.38/1.3). Although no significant differences between cariogenic microorganism counts were observed, significantly higher yeasts oral levels were observed in SCA group. Controls showed lower salivary buffering capacity. Candida albicans was the most frequently isolated species in both groups. Candida famata, Candida parapsilosis and Candida tropicalis were also isolated from controls. Candida dubliniensis, Candida rugosa and Candida sphaerica were found only in SCA group. CONCLUSIONS: Based on the results, it could be concluded that paediatric patients with SCA showed significantly higher oral level of yeasts. Uncommon fungal species were found in SCA group. Similar caries prevalence and counts of lactobacilli and streptococci in relation to controls were observed.

Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia.

A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years) and their matched controls (healthy children). One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 µg glucose/mg biofilm; 7,503±3,097 µg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 µg glucose/mg biofilm; 4,995±682 µg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025), polysaccharides (p=0.025) and proteins (p=0.047) compared with the isolates from control group. However, there was no difference in metabolic activity (XTT) between groups (p=0.750). Conclusion The C. albicans biofilms from patients with sickle-cell anemia presented a greater caries-associated virulence than isolates from healthy children.