Microbial Reduction by Two Chemical-Mechanical Protocols in Primary Teeth with Pulp Necrosis and Periradicular Lesion - An In Vivo Study

The objective of this study was to determine the efficacy of chemical-mechanical procedures of two endodontic protocols for septic content reduction of root canals from primary teeth with pulp necrosis and periradicular lesion. Twenty-four primary root canals with pulp necrosis and periradicular lesion were divided into two treatment groups (n=12): multiple-visit and single-visit protocols. Samples were collected using sterile paper points before and after endodontic cleaning followed by microbiological identification through checkerboard DNA-DNA hybridization. Statistical analysis was performed using Proportion Test for score=0 comparing the findings before and after treatment for each group (Wilcoxon's test) as well as the differences in scores between protocols (Mann-Whitney's test) (p<0.05). Data were expressed as prevalence (presence or absence) and estimate of the average count (x105 cells) of each species. Differences in proportions of score=0 prior to treatment were non-significant (p=0.415), demonstrating equivalence between groups. A significant increase in score=0 was detected after treatment for both groups (p<0.0001). Single-visit protocol achieved a significantly greater reduction in mean scoring following endodontic treatment (p=0.024). Both protocols were capable of significantly reducing septic content in root canals of primary teeth with periradicular lesion. Moreover, single-visit protocol showed greater efficacy in reducing endodontic infection.

O objetivo deste estudo foi determinar a eficácia das manobras químico-mecânicas de dois protocolos endodônticos, na redução do conteúdo séptico de canais radiculares de dentes decíduos com polpa necrosada e lesão perirradicular. Vinte e quatro canais radiculares decíduos com necrose pulpar e lesão perirradicular foram divididos em dois grupos de tratamento (n=12): multisessões e sessão única. Amostras foram coletadas usando pontas de papel estéreis, antes e após a limpeza endodôntica, seguido de identificação microbiológica por hibridização DNA-DNA checkerboard. A análise estatística foi realizada usando teste de proporções para escore=0, comparando os achados antes e após tratamento para cada grupo (teste de Wilcoxon) e as diferenças dos escores entre os protocolos (teste de Mann-Whitney) (p<0,05). Os dados foram expressos em prevalência (presença ou ausência) e contagem média (x105 células) de cada espécie. As diferenças nas proporções de escore=0 antes do tratamento não foram significativas (p=0,415), mostrando equivalência entre os grupos. Um aumento significativo de escore=0 foi detectado após o tratamento para ambos os grupos (p<0,0001). O protocolo de sessão única mostrou uma redução significativamente maior dos escores médios após o tratamento endodôntico (p=0,024). Ambos os protocolos são capazes de reduzir significativamente o conteúdo séptico de canais radiculares de dentes decíduos com lesão perirradicular. Entretanto, o protocolo de sessão única mostrou uma maior eficácia na redução da infecção endodôntica.

Response of human dental pulp to calcium hydroxide paste preceded by a corticosteroid/ antibiotic dressing agent

Aim: To evaluate the treatment with corticosteroid/antibiotic dressing in pulpotomy with calciumhydroxide. Methods: Forty-six premolars were pulpotomized and randomly assigned into 3groups. In Group I pulpal wound was directly capped with calcium hydroxide, and Group II and Group III received corticosteroid/antibiotic dressing for 10 min or 48 h, respectively, before pulp capping. Teeth were processed for histological analysis after 7, 30 or 60 days to determine inflammatory cell response, tissue disorganization, dentin bridge formation and presence of bacteria.Attributed scores were analyzed by Kruskal-Wallis and Mann-Whitney tests (á=0.05). Results:On the 7th day, all groups exhibited dilated and congested blood vessels in the tissue adjacent to pulpal wound. The inflammatory cell response was significantly greater in Group III (p<0.05). On the 30th day, in all groups, a thin dentin matrix layer was deposited adjacent to the pulpal wound and a continuous odontoblast-like cell layer underlying the dentin matrix was observed. On the60th day, all groups presented a thick hard barrier characterized by an outer zone of dystrophic calcification and an inner zone of tubular dentin matrix underlined by a defined odontoblast-like celllayer. Conclusions: Within the limitations of present study, considering that the treatment was performed in healthy teeth, it may be concluded that the use of a corticosteroid/antibiotic dressing before remaining tissue protection with calcium hydroxide had no influence on pulp tissue healing.

Microbiological and microscopic analysis of the pulp of non-vital traumatized teeth with intact crowns

OBJECTIVE: This study evaluated the presence of microorganisms and analyzed microscopically the pulp of 20 traumatized human teeth with intact crowns and clinical diagnosis of pulp necrosis, based on the association of at least three of the clinical criteria: crown discoloration, negative response to thermal and electric pulp vitality tests, positive response to vertical and horizontal percussion, pain on palpation or mobility. MATERIAL AND METHODS: Microbiological collection was performed from the root canals to evaluate the presence of microorganisms. The pulp samples were stained with hematoxylin and eosin (H.E.) for histological evaluation of possible morphological alterations. RESULTS: Analysis of results was performed by statistical tests (linear regression test and diagnostic analysis) and subjective analysis of the sections stained with H.E. and revealed that only 15 percent of the sample did not exhibit microbial development. The time elapsed between dental trauma and onset of endodontic intervention ranged from 15 days to 31 months; the percussion test presented high sensitivity (80 percent) for detection of microorganisms in the root canal of traumatized teeth; 3 teeth (15 percent) did not present pulp tissue, being characterized as complete autolysis; analysis of pulp samples was performed on the other 17 cases, among which 3 (15 percent) exhibited partial necrosis without possibility of repair and 14 presented complete necrosis; none of the clinical criteria employed for the diagnosis of pulp necrosis in traumatized teeth was pathognomonic. CONCLUSIONS: The present results allowed the following conclusions: with regard to microbiological findings, 85 percent of teeth presented microorganisms in the root canal, despite the presence of an intact crown. Concerning the microscopic findings, 100 percent of traumatized teeth presented pulp necrosis; the pulp vitality tests based on pulp response to heat, cold and vertical percussion ...

Evaluation of the antimicrobial effects of mtad, naoci against selected endodontic pathogens

The aim of this study was to compare the antimicrobial effects of MTAD, sodium hypochlorite [NaOCl] and their combination on endodontic micro-organisms.Zone of Inhibition [ZI] and Minimum Inhibitory Concentration [MIC] were the techniques used. In ZI technique blood agar plates were inoculated with organisms, paper discs were soaked with irrigants and maximum zones of bacterial inhibition were recorded. In the MIC technique the irrigants were serially diluted in TSB tubes and 0.1 mL of the tested microbe solutions were added. Results were obtained on the basis of turbidity and growth on agar plates. Statistical analyses were carried out using ANOVA and Tukey tests.In ZI technique, we investigated 120 specimens including 5 microbial species, 3 irrigants and their control groups, each with 6 repetitions. The results demonstrated MTAD greater antimicrobial efficacy compared to NaOCl, and their mixture [M+N] against Staphylococcus [S] aureus, Enteric [E] bacteria and Enterococcus [E] faecalis [P < 0.001]. NaOCl was more effective in eradicating Candida [C] albicans than the others [P < 0.01]. MIC method [155 tubes] showed MTAD to be more effective against E. bacteria and S. aureus. MTAD and NaOCl were equally effective against E. faecalis; however, NaOCl was more effective against C. albicans.Bacterial species were more susceptible to MTAD than NaOCl, C. albicans, however, was more susceptible to NaOCl. The advantage of NaOCl is that it has broad spectrum antimicrobial activity. The joint solution [M+N] did not prove to be more effective than their individual use

The reaction of dental pulp to Escherichia coli lipopolysaccharide and Enterococcus faecalis lipoteichoic acid

This research evaluates the effects of the lipopolysaccharides (LPS) from Escherichia coli and lipoteichoic acid (LTA) from Enterococcus faecalis on dental pulp. These molecules are components of the Gram-negative and Gram-positive bacteria cell wall, respectively. Ten dogs were used in the experiment. Inoculation in surgically opened pulp and coronal restoration with glass ionomer was the method chosen. The evaluation times were 1, 7, 15, 30 and 60 days. The results showed that the LPS and LTA, at 150 icg/ml, produced a negative interference in the pulp leading to destruction. LTA caused less damage than LPS.

Compatibilidade biológica de resina resorcina - formaldeído quando aplicada sobre dentina em pré-molares humanos. Avaliação em microscopia óptica e eletrônica de transmissão / Evalution of the effects on human pre-molar pulp of resorcinol-formaldehyde resin applied over dentine. An light and electron microscopy study

O objetivo deste trabalho foi avaliar a compatibilidade biológica da resina resorcina-formaldeído quando aplicada diretamente sobre dentina. Trinta e seis premolares humenos íntegros, indicados para extração por motivos ortodônticos, foram divididos em três grupos: grupo experimental, 22 cavidades classe V foram preparadas e forradas com resina resorcina-formaldeído; grupo controle I, 8 cavidades foram forradas com cimento de hidróxido de cálcio. As cavidades destes dois grupos foram restauradas com amálgama. No grupo controle II, 6 premolares foram mantidos íntegros. Os dentes foram extraídos após, 7, 15, 30 e 120 dias de realização das restaurações e cortes histológicos foram preparados para avaliação em M.E.T.. Outros ainda, com 6 µ m de espessura, foram corados co hematoxilina e eosina, tricrômico de Masson e pela técnica de Brow e Brenn para evidenciar bactérias.

Efecto del piroxicam sobre la microflora local en el complejo pulpoperiapical posterior a la exposición pulpar / Effect of piroxicam on local microflora on the pulp-periapical complex, after pulp exposure

El objetivo de este reporte fue determinar el efecto del piroxicam (antiinflamatorio no esteroide) sobre las bacterias en el complejo pulpoperiapical, cuando se administra para inhibir el desarrollo de lesiones periapicales experimentales. A 12 ratas cepa long Evans se les provocó exposición pulpar previo a la administración de piroxicam, administrando el medicamento cada 24 horas durante 15 días. Se encontró que el porcentaje de bacterias decrece de la cámara pulpar hacia el periápice observándolos escasos en la lesión periapical en ambos grupos, sin embargo se encuentran incrementados con respecto a porcentajes en el grupo al cual se le administró el piroxicam, lo que sugiere que si bien el piroxicam disminuye el desarrollo de lesiones periapicales, favorece el desarrollo de bacterias incrementando su número en el complejo pulpoperiapical