At-home bleaching with carbamide peroxide with concentrations below 10%: bleaching efficacy and permeability in the pulp chamber.

OBJECTIVES: To evaluate the bleaching efficacy and permeability of hydrogen peroxide (HP) in the pulp chamber of human teeth bleached with lower concentrations of carbamide peroxide gel (4%, 5% and 7% CP). MATERIALS AND METHODS: Bleaching gels with lower concentrations were formulated and a commercial standard gel, 10% CP, was used as a reference. Fifty-six human premolars were randomly divided into four groups. Applications of the bleaching gel were made for 3 h for 21 days. The bleaching efficacy was evaluated by digital spectrophotometry on 1, 7, 14 and 21 days, with analysis in the ∆Eab, ∆E00 and WID color spaces. The concentration of HP in the pulp chamber was measured in the same periods by UV-Vis spectrophotometry (µg/mL). Two-way repeated analysis of variance (ANOVA) examined bleaching efficacy and HP permeability, followed by Tukey's post-hoc test (α = 0.05). RESULTS: All groups showed significant color changes, with no statistical differences after the second and third week of bleaching (p > 0.05). The 'time' factor was statistically different (p < 0.05), increasing the bleaching efficacy throughout the treatment. The 4% CP group had lower HP levels in the pulp chamber (p < 0.05). CONCLUSIONS: The results seem promising, revealing that low concentration gels are as effective as 10% CP with the benefit of reducing the amount of HP in the pulp chamber. CLINICAL RELEVANCE: Low concentration 4% PC and 5% PC maintains bleaching efficacy, reduces the penetration of HP peroxide into the pulp chamber, and may reduce tooth sensitivity.

Evaluating color change and hydrogen peroxide penetration in human and bovine teeth through in-office bleaching procedures.

OBJECTIVE: Assess color alteration and hydrogen peroxide (HP) penetration in human and bovine teeth using various in-office bleaching protocols with different application times. MATERIALS AND METHODS: Thirty healthy human premolars and 30 healthy bovine incisors were divided into five groups and subjected to different bleaching protocols: 2 × 15 min, 1 × 30 min, 2 × 20 min, or 1 × 40 min, with a control group for each tooth type. All teeth were treated with 35% HP gel. Color alteration was measured using digital spectrophotometry before and 1 week after bleaching. HP concentration within the pulp was determined via UV-Vis spectrophotometry. Statistical analysis included one-way ANOVA, Tukey's, and Dunnett's tests (α = 0.05). RESULTS: All groups exhibited significant color alteration, with no statistically differences among them (p > 0.05). However, significant differences were observed when compared with their respective control groups (p < 0.05). HP penetration into the pulp was evident in all bleached teeth compared to the control groups (p < 0.05), with the 2 × 20 group showing the highest HP levels within the pulp cavity, irrespective of tooth type (p < 0.05). CONCLUSION: A simplified 1 × 30-min protocol can be recommended as it effectively maintains color alteration and HP penetration, irrespective of whether human or bovine teeth. CLINICAL SIGNIFICANCE: This study suggests that an in-office dental bleaching protocol using a 1 × 30-min session is recommended, as it ensures both effective color change and no increase in the amount of HP penetration.

Lesões periapicais de origem não-endodôntica: uma revisão integrativa

O objetivo deste trabalho foi elencar quais são as principais lesões periapicais que não têm origem a partir da necrose pulpar. Para tanto, realizou-se uma revisão integrativa da literatura, com busca nas bases de dados Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Medical Literature Analysis and Retrievel System Online (MEDLINE) e Bibliografia Brasileira de Odontologia (BBO). Os descritores utilizados foram "doenças periapicais" e "diagnóstico diferencial", combinados com o operador booleano "AND". Foram encontrados 42 artigos que responderam aos critérios de inclusão e exclusão. A análise dos estudos incluídos mostrou que as principais lesões periapicais de origem não endodôntica são o queratocisto odontogênico e o ameloblastoma. Embora a prevalência de lesões periapicais não endodônticas seja baixa, é importante estar atento aos possíveis diagnósticos diferenciais, visto que as lesões que mais apareceram na literatura se tratam de patologias localmente agressivas e potencialmente mutiladoras. Ademais, a conduta do profissional que se depara com qualquer tipo de lesão periapical que apresente comportamento fora dos padrões de normalidade deve ser a realização de biópsia e análise histopatológica.

The aim of this study was to list the main periapical lesions that do not originate from pulpal necrosis. An integrative literature review was carried out, with a search in the Latin American and Caribbean Literature in Health Sciences (LILACS), Medical Literature Analysis and Retrievel System Online (MEDLINE) and Bibliografia Brasileira de Odontologia (BBO) databases. The keywords used were "periapical diseases" and "differential diagnosis", combined with the boolean operator "AND". 42 articles were found that met the inclusion and exclusion criteria. The analysis of the included studies showed that the main periapical lesions of non-endodontic origin are the odontogenic keratocyst and the ameloblastoma. Although the prevalence of non-endodontic periapical lesions is low, it is important to be aware of possible differential diagnoses, since the lesions that most appeared in the literature are locally aggressive and potentially mutilating pathologies. In addition, the conduct of the professional who is faced with any type of periapical lesion that presents behavior outside the normal range should be to perform a biopsy and histopathological analysis.