Subcutaneous tissue response of isogenic mice to calcium hydroxide-based pastes with chlorhexidine

This study was evaluated the response of subcutaneous connective tissue of isogenic mice to calcium hydroxide-based pastes with chlorhexidine digluconate (CHX). Seventy isogenic male BALB/c mice aged 6-8 weeks and weighing 15-20 g were randomly assigned to 8 groups. The animals received polyethylene tube implants as follows: Groups I, II, and III (n=10) - Calen® paste mixed with 0.4% CHX (experimental paste; Calen/CHX) for 7, 21, and 63 days, respectively; Groups IV, V, and VI (n=10) - UltraCal™ paste mixed with 2% CHX (experimental paste supplied by Ultradent Products Inc.; Ultracal/CHX) for 7, 21, and 63 days, respectively; and Groups VII and VIII (n=5): empty tube for 7 and 21 days, respectively. At the end of the experimental periods, the implants were removed together with the surrounding tissues (skin and subcutaneous connective tissue). The biopsied tissues were subjected to routine processing for histological analysis. Using a descriptive analysis and a four-point (0-3) scoring system, the following criteria were considered for qualitative and quantitative analysis of the tissue around the implanted materials: collagen fiber formation, tissue thickness and inflammatory infiltrate. A quantitative analysis was performed by measuring the thickness (µm), area (µm²) and perimeter (µm) of the reactionary granulomatous tissue formed at the tube ends. Data were analyzed statistically by the Kruskal-Wallis test and Dunn's post-test (α=0.05). Calen/CHX showed biocompatibility with the subcutaneous and reactionary tissues, with areas of discrete fibrosis and normal conjunctive fibrous tissue, though without statistically significant difference (p>0.05) from the control groups. In Groups I to III, there was a predominance of score 1, while in Groups IV to VI scores 2 and 3 predominated for all analyzed parameters. UltraCal/CHX, on the other hand, induced the formation of an inflammatory infiltrate and abundant exudate, suggesting a persistent residual aggression from the material, even 63 days after implant placement. In conclusion, the Calen paste mixed with 0.4% CHX allowed an adequate tissue response, whereas the UltraCal paste mixed with 2% CHX showed unsatisfactory results.O objetivo do presente estudo foi avaliar a resposta do tecido conjuntivo subcutâneo de camundongos isogênicos frente a pastas à base de hidróxido de cálcio, associadas ao digluconato de clorexidina (CHX). Setenta camundongos isogênicos BALB/c machos, com 6-8 semanas e pesando 15-20 g foram aleatoriamente divididos em 8 grupos. Os animais receberam implantes de tubos de polietileno contendo: Grupos I, II e III (n=10) - pasta Calen® associada à CHX a 0,4% (Calen/CHX), por 7, 21 e 63 dias, respectivamente; Grupos IV, V e VI (n=10) - pasta UltraCal™ associada à CHX a 2% (pasta experimental fornecida pela Ultradent Products Inc.; Ultracal/CHX), por 7, 21 e 63 dias, respectivamente; e Grupos VII e VIII (n=5) - tubo de polietileno vazio, por 7 e 21 dias, respectivamente. Decorridos os períodos experimentais, os implantes foram removidos juntamente com os tecidos circundantes (pele e tecido conjuntivo). Os tecidos foram submetidos ao processamento histotécnico de rotina, para análise histopatológica. Empregando um sistema de escores, os seguintes critérios foram considerados para a análise qualitativa e quantitativa: fibrosamento, espessura tecidual e infiltrado inflamatório. Foi efetuada, também, a análise quantitativa da medida da espessura (µm), área (µm²) e perímetro (µm) do tecido granulomatoso reacional formado na abertura dos tubos. Os dados obtidos foram submetidos à análise estatística, empregando o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância adotado foi de 5%. Os resultados demonstraram biocompatibilidade da pasta Calen associada à CHX a 0,4% com o tecido adjacente, com fibrosamento discreto, assim como tecido conjuntivo normal, sem diferença estatística significante com os controles (p>0,05). Nos Grupos I, II e III houve predominância do escore 1, enquanto que nos Grupos IV, V e VI houve predominância dos escores 2 e 3, em todos os parâmetros analisados. Em relação à pasta à base de hidróxido de cálcio associada à CHX a 2% (UltraCal™) observou-se infiltrado inflamatório e exsudato severo, sugerindo uma agressão residual persistente do material testado, mesmo após 63 dias da sua implantação. Em conclusão, a adição de CHX a 0,4% à pasta Calen permitiu adequada resposta tecidual, enquanto o hidróxido de cálcio associado à CHX na concentração de 2% (UltraCal/CHX) evidenciou resultados insatisfatórios

Antibacterial activity of root canal filling materials for primary teeth: zinc oxide and eugenol cement, Calen paste thickened with zinc oxide, Sealapex and EndoREZ

This study evaluated in vitro the antibacterial activity of 4 root canal filling materials for primary teeth - zinc oxide and eugenol cement (ZOE), Calen paste thickened with zinc oxide (Calen/ZO), Sealapex sealer and EndoREZ sealer - against 5 bacterial strains commonly found in endodontic infections (Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli and Staphylococcus aureus) using the agar diffusion test (agar-well technique). Calen paste, 1% chlorhexidine digluconate (CHX) and distilled water served as controls. Seven wells per dish were made at equidistant points and immediately filled with the test and control materials. After incubation of the plates at 37oC for 24 h, the diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a digital caliper under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (?=0.05). There were statistically significant differences (p<0.0001) among the zones of bacterial growth inhibition produced by the different materials against all target microorganisms. K. rhizophila was inhibited more effectively (p<0.05) by ZOE, while Calen/ZO had its highest antibacterial activity against E. faecalis (p<0.05). S. mutans was inhibited by Calen/ZO, Sealapex and ZOE in the same intensity (p>0.05). E. coli was inhibited more effectively (p<0.05) by ZOE, followed by Calen/ZO and Sealapex. Calen/ZO and ZOE were equally effective (p>0.05) against S. aureus, while Sealapex had the lowest antibacterial efficacy (p<0.05) against this microorganism. EndoREZ presented antibacterial activity only against K. rhizophila and S. aureus. The Calen paste and Calen/ZO produced larger zones of inhibition than 1% CHX when the marker microorganism was E faecalis. In conclusion, the in vitro antibacterial activity of the 4 root canal filling materials for primary teeth against bacterial strains commonly found in endodontic infections can be presented in a decreasing order of efficacy as follows: ZOE>Calen/ZO>Sealapex>EndoREZ.Este estudo avaliou in vitro a atividade antibacteriana de 4 materiais obturadores de canais radiculares de dentes decíduos - cimento de óxido de zinco e eugenol (OZE), pasta Calen espessada com óxido de zinco (Calen/OZ), cimento Sealapex e cimento EndoREZ - sobre 5 cepas bacterianas comumente encontradas em infecções endodônticas: Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli e Staphylococcus aureus, usando o teste de difusão em ágar (técnica do poço). A pasta Calen, digluconato de clorexidina a 1% (CHX) e água destilada foram usados como controle. Sete poços por placa foram preparados em pontos eqüidistantes e imediatamente preenchidos com os materiais experimentais e controle. Após incubação das placas a 37oC por 24 h, o diâmetro dos halos de inibição do crescimento bacteriano formados ao redor dos poços foi medido (em mm) com um paquímetro digital sob luz refletida. Os dados obtidos foram submetidos à análise de variância e ao pós-teste de Tukey (?=0,05). Com relação à atividade antibacteriana, evidenciaram-se diferenças estatisticamente significantes (p<0,0001) entre os halos de inibição formados pelos diferentes materiais, para todos os microrganismos avaliados. A K. rhizophila foi inibida mais eficazmente pelo OZE (p<0,05), enquanto que o E. faecalis foi inibido mais eficazmente pela Calen/OZ (p<0,05). O S. mutans foi inibido pela Calen/OZ, cimento Sealapex e OZE na mesma intensidade (p>0,05). A E. coli foi inibida mais eficazmente pelo OZE, seguido pela Calen/OZ e pelo cimento Sealapex (p<0,05). O S. aureus foi inibido pela Calen/OZ e OZE na mesma intensidade (p>0,05), e menos intensamente pelo cimento Sealapex (p<0,05). O cimento EndoREZ apresentou atividade antibacteriana apenas frente a K. rhizophila e ao S. aureus. A pasta Calen e a Calen/OZ ocasionaram halos de inibição maiores que a CHX quando o microrganismo indicador foi o E. faecalis. Pode-se concluir que a atividade antibacteriana, in vitro, dos 4 materiais obturadores de canais radiculares de dentes decíduos sobre cepas bacterianas comumente encontradas em infecções endodônticas pode ser apresentada numa ordem decrescente de eficácia da seguinte maneira: OZE>Calen/OZ>Sealapex>EndoREZ

Quantitative radiographic evaluation of periapical bone resorption in dog's teeth contaminated with bacterial endotoxin (LPS) associated or not with calcium hydroxide

The aim of this study was to quantify radiographically the periapical bone resorption in dogs' teeth contaminated with bacterial endotoxin (LPS), associated or not with calcium hydroxide. After pulp tissue removal, 60 premolars were randomly assigned to 4 groups and were either filled with LPS (group 1), filled with LPS plus calcium hydroxide (group 2) or filled with saline (group 3) for a period of 30 days. In group 4, periapical lesion formation was induced with no canal treatment. Standardized radiographs were taken at the beginning of the treatment and after 30 days and the Image J Program was used for measurement of periapical lesion size. Periapical lesions were observed in groups 1 (average of 8.44 mm2) and 4 (average of 3.02 mm2). The lamina dura was intact and there were no areas of periapical bone resorption in groups 2 and 3. It may be concluded that calcium hydroxide was effective in inactivating LPS, as demonstrated by the absence of apical periodontitis in the roots that were filled with bacterial endotoxin plus calcium hydroxide.O objetivo deste estudo foi quantificar radiograficamente a reabsorção óssea periapical em dentes de cães contaminados com endotoxina bacteriana (LPS), associadas ou não ao hidróxido de cálcio. Sessenta pré-molares foram divididos em 4 grupos e preenchidos com LPS (grupo 1), LPS e hidróxido de cálcio (grupo 2), solução salina (grupo 3), ou lesões periapicais foram induzidas sem tratamento (grupo 4), por um período de 30 dias e o Programa Image J foi empregado para mensuração das lesões, em mm2. Radiografias foram realizadas no início do tratamento e após 30 dias. Lesões periapicais foram observadas no grupo 1 (média de 8,44 mm2) e 4 (média de 3,02 mm2). A lâmina dura estava intacta e não foram observadas áreas de reabsorção óssea periapical nos grupos 2 e 3. Concluindo, a avaliação radiográfica quantitativa do efeito do LPS associado ao hidróxido de cálcio demonstrou que quando juntos a endotoxina bacteriana é inativada, uma vez que não foram observadas lesões periapicais nas raízes deste grupo experimental

Pulpal and Periapical response after restoration of deep cavities in dogs' teeth with filtek silorane and filtek supreme xt systems.

Abstract OBJECTIVE: This study evaluated, histopathologically, the pulpal and periapical response to a silorane-based resin (Filtek Silorane) and a methacrylate-based nanoparticle resin (Filtek Supreme XT) in deep cavities in dogs, having zinc oxide and eugenol-based cement (ZOE) as a control. METHODS: The tooth/bone blocks were collected after 10 and 90 days and processed for microscopic analysis of the dentin, pulp, and periapical tissues using a score system. Data were analyzed statistically by Kruskal-Wallis and Dunn post-test (α=0.05). RESULTS: At 10 days, the pulp, connective tissue, and periodontal ligament showed normal characteristics. No resorption areas were observed. Both resins caused significantly less (p<0.05) periapical and pulpal inflammatory response than ZOE. At 90 days, for all materials, the connective pulp tissue was healthy and dense, with a normal blood vessel system. The apical and periapical region had normal structure and thickness. CONCLUSIONS: The use of the Filtek Silorane and the Filtek Supreme XT resins caused no adverse pulpal and periapical reactions after restoration of deep dentin cavities in vivo

Use of Restorative Materials in Primary Teeth – A Retrospective University-Based Study

Objective: To investigate the types of restorative materials used for restorative treatment in primary teeth through a retrospective university-based study. Material and Methods: The sample consisted of all clinical records of children attended at the Pediatric Dentistry Clinic at the School of Dentistry of Ribeirão Preto at the University of São Paulo in Brazil. Inclusion criteria were primary anterior and posterior teeth that received dental restorations for treatment of dental caries lesions, dental trauma or dental development defects from 2013 to 2018. Restoration repairs and interim restorations during this period were also recorded. Descriptive analyzes were performed to assess the distribution according to the type of restorative material used over the years. Results: A total of 5,236 restorative procedures were performed in primary teeth, including restoration repair and interim restorations. Of those, 69% were done in posterior teeth and 31% in anterior teeth. Sixty percent of the procedures performed during this period were made of composite resin and a lower percentage of glass ionomer cement (18%) followed by silver amalgam (1%). The number of interim restorations was smaller but proportional to those of composite resin over the years. Conclusion: A tendency to carry out restorative treatment of primary teeth with composite resin during the 6 years of follow-up was observed

Microbial contamination and disinfection methods of pacifiers.

Abstract OBJECTIVES: To evaluate the microbial contamination of pacifiers by Mutans Streptococci(MS) and the efficacy of different methods for their disinfection. METHODS: Twenty-eight children were assigned to a 4-stage changeover system with a 1-week interval. In each stage, children received a new pacifier and the parents were instructed to maintain their normal habits for 1 week. After this time, the pacifiers were subjected to the following 4 disinfection methods: spraying with 0.12% chlorhexidine solution, Brushtox or sterile tap water, and immersion in boiling tap water for 15 minutes. Microbiological culture for MS and Scanning Electron Microscopy (SEM) were performed. The results were analyzed statistically by Friedman's non-parametric test (a=0.05). RESULTS: The 0.12% chlorhexidine spray was statistically similar to the boiling water (p>0.05) and more effective than the Brushtox spray and control (p<0.05). The analysis of SEM showed the formation of a cariogenic biofilm in all groups with positive culture. CONCLUSIONS: Pacifiers become contaminated by MS after their use by children and should be disinfected routinely. Spraying with a 0.12% chlorhexidine solution and immersion in boiling water promoted better disinfection of the pacifiers compared with a commercial antiseptic toothbrush cleanser (Brushtox)

Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p;0.05). However, a lower number of osteoclasts was observed in the ANP group (

Apical Periodontitis Healing Following Treatment is Impacted by Root Canal Sealer Composition: An in Vivo and in Vitro Investigation

Objective: To evaluate the periapical healing following root canal treatment in teeth with apical periodontitis (in vivo) and the cytotoxic potential of root canal sealers in vitro. Material and Methods: Apical periodontitis was induced in 60 dogs' teeth and root canals were filled with Sealapex (40 roots), EndoREZ (40 roots), intracanal dressing (20 roots), or left untreated (20 roots). After 30 and 90 days, histopathological analyses were made. In vitro, J774.1 macrophages were stimulated with root canal sealers extracts, cytotoxicity was assessed using lactate dehydrogenase assay, and qRT-PCR was used to analyze TNF-α gene expression. Results: In vivo, smaller apical periodontitis and lower inflammatory cell infiltrate were found in teeth treated with Sealapex compared to EndoREZ. In vitro, EndoREZ was cytotoxic and induced TNF-α gene expression by macrophages differently from Sealapex. Conclusion: Sealapex allowed improved tissue repair following root canal treatment in teeth with apical periodontitis compared to EndoREZ. Synthesis of TNF-α induced by LPS was enhanced by EndoREZ, whereas Sealapex prevented pro-inflammatory gene expression

Microbial contamination and disinfection methods of pacifiers

Objectives To evaluate the microbial contamination of pacifiers by Mutans Streptococci(MS) and the efficacy of different methods for their disinfection.Methods Twenty-eight children were assigned to a 4-stage changeover system with a 1-week interval. In each stage, children received a new pacifier and the parents were instructed to maintain their normal habits for 1 week. After this time, the pacifiers were subjected to the following 4 disinfection methods: spraying with 0.12% chlorhexidine solution, Brushtox® or sterile tap water, and immersion in boiling tap water for 15 minutes. Microbiological culture for MS and Scanning Electron Microscopy (SEM) were performed. The results were analyzed statistically by Friedman’s non-parametric test (a=0.05).Results The 0.12% chlorhexidine spray was statistically similar to the boiling water (p>;0.05) and more effective than the Brushtox®spray and control (