Microbiota of dental caries in primary teeth of a Costa Rican Child population / Microbiota de la caries dental en piezas primarias de una población infantil costarricense

Abstract The objective of this research was to identify bacteria present in the microbiota of dentinal carious lesions in primary molars of some Costa Rican pediatric patients. Data were collected from 15 children aged between 4 and 8 years old who attended the Pediatric Dentistry Clinic at the Faculty of Dentistry from the University of Costa Rica (UCR). The inclusion criteria were: infants between 4 and 8 years old who presented cavitated carious lesions in primary teeth, who were actively attended by students at the Faculty of Dentistry from the UCR, and whose parents or legal guardians signed the informed consent to participate in this research. Samples were taken using a sterile spoon, placed in storage vials, and subjected to various conventional and molecular microbial identification techniques, such as Gram stain identification, catalase tests, oxidase, TSI, API 20E, API STAPH, and VITEK 2. Of the 60 bacterial strains subjected to Gram staining, the following was obtained: 28 Gram-positive bacteria and 32 Gram-negative bacteria. The main isolated organisms were species of Staphylococcus epidermidis, Pasteurella pneumotropica/Mannheimia haemolytica, Pantoea spp, and Streptococcus mutans.

Resumen El objetivo de esta investigación fue identificar las bacterias presentes en la microbiota de lesiones cariosas dentinales en molares primarias de pacientes pediátricos costarricenses. Las muestras fueron recolectadas de 15 niños entre los 4 y 8 años que fueron atendidos en la Clínica de Odontopediatría en la Facultad de Odontología de la Universidad de Costa Rica (UCR). Los criterios de inclusión fueron: pacientes entre los 4 y los 8 años de edad que presentaran lesiones cariosas cavitadas en dientes primarios, que se encuentraran activos para su atención por estudiantes de la Facultad de Odontología de la UCR, y que los padres o encargados legales firmaran el consentimiento informado para participar en esta investigación. Las muestras se tomaron utilizando una cuchareta estéril, colocándolas en viales de almacenamiento y fueron sometidas a diversas técnicas de identificación microbiana convencionales y moleculares tales como: identificación por Tinción de Gram, pruebas catalasa, oxidasa, TSI, API 20E, API STAPH y VITEK. De las 60 cepas bacterianas sometidas a tinción de Gram se obtuvo: 28 bacterias Gram Positivas y 32 bacterias Gram Negativas. Los principales organismos aislados fueron: especies de Staphylococcus epidermidis, Pasteurella pneumotropica/ Mannheimia haemolytica, Pantoea spp y Streptococcus mutans.

Do Different Proportions of Antibiotics in the CTZ Paste Interfere with the Antimicrobial Action? In Vitro Study

Abstract Objective: To evaluate the antimicrobial action of the CTZ paste in three different proportions by diffusion in agar with the microorganisms: Enterococcus faecalis,Escherichia coli, and Candida albicans. Material and Methods: Three different proportions of antibiotics were tested: GROUP A - CTZ paste in the ratio of 33.33% chloramphenicol + 33.33% tetracycline + 33.33% zinc oxide, mixed with 2 drops of eugenol (1:1:1 ratio); GROUP B - CTZ paste in the proportion of 25% chloramphenicol + 25% tetracycline + 50% zinc oxide, mixed with 2 drops of eugenol (1: 1: 2 ratio); GROUP C - CTZ paste with 13% chloramphenicol + 13% tetracycline + 74% Zinc Oxide, mixed with 2 drops of eugenol (1:1:6 ratio); PC GROUP - Positive Control (0.12% Chlorhexidine); and NC GROUP - Negative Control (0.9% Saline solution). Data were analyzed through descriptive statistics (means and standard deviation). The one-way ANOVA and Tukey's test were used, with a significance level of 5% Results: No statistical differences for Enterococcus faecalis between groups A, B, and C (p = 0.1986) were found. There were statistical differences for Escherichia coli between groups B and C (p = 0.029), and for Candida albicans between groups A and C (p = 0.006). Groups A, B, and C had significant differences with both Positive and Negative Controls for all the microorganisms Conclusion: The three different ratios of CTZ paste showed antimicrobial efficacy against Enterococcus faecalis,Escherichia coli, and Candida albicans microorganisms.

Comparative Molecular Analysis of Gram-Negative Bacteria in Primary Teeth with Irreversible Pulpitis or Periapical Pathology.

Purpose: The purpose of this study was to compare the Gram-negative pathogens identified in the root canals of primary teeth with irreversible inflammatory pulpitis and in teeth showing apical periodontitis. Methods: Samples were collected from 123 root canals of primary teeth from three- to seven-year-old patients. Root canals were assigned to either group one (irreversible inflammatory pulpitis; n equals 63) or group two (pulp necrosis and apical periodontitis; n equals 60). Total number of cells of selected Gram-negative microorganisms was determined by the checkerboard DNA-DNA hybridization technique. Demographic data were compared using either chi-squared or t tests. Total numbers of microorganisms were compared using the Mann-Whitney test (α equals 0.05). Results: There were no significant intergroup differences in gender, age, and tooth group distribution (P>0.05). Among the 123 samples, 17 were discarded due to salivary contamination. The total numbers of Prevotella nigrescens, Treponema denticola, Fusobacterium nucleatum polymorphum, Fusobacterium nucleatum spp nucleatum, Aggregatibacter actinomycetemcomitans serotype a, Aggregatibacter actinomycetemcomitans serotype b, Porphyromonas gingivalis, Prevotella intermedia, and Prevotella melaninogenica were higher in teeth with apical periodontitis compared to those with irreversible inflammatory pulpitis (P<0.05). Conclusion: Higher numbers of Gram-negative bacteria were found in teeth with apical periodontitis compared to teeth with irreversible in- flammatory pulpitis.

Antimicrobial Photodynamic Therapy as an Adjunct for Clinical Partial Removal of Deciduous Carious Tissue: A Minimally Invasive Approach.

This study aimed to evaluate the use of antimicrobial photodynamic therapy (aPDT) as an adjunct for minimally invasive treatment (partial removal of carious tissue-PRCT) of deciduous carious tissue evaluating its efficacy in reducing microorganisms. For that, a clinical study was design including children with deciduous molars with active deep caries lesions (DCL). PRCT was performed and remaining dentin was treated with 100 µg mL-1 methylene blue solution (5 min) and than irradiated with a low power laser emitting red light (InGaAIP-indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 300 J cm-2 ; 90 s; 9 J). The colony forming units (CFU) count after PRCT and after PRCT + aPDT/mg of dentin were compared for total microorganisms, including Candida spp., the mutans streptococci group, Streptococcus spp. and Lactobacillus spp. The dentin was classified (color, consistency and humidity). The microbial reduction varied from 69.88% to 86.29% and was significantly observed for total microorganisms, mutans streptococci, Streptococcus spp. and Lactobacillus spp (P < 0.001). The dentin type did not influence reduction of microorganisms (P > 0.05). The aPDT presents a promising future for clinical use as an adjunct for the reduction of microorganisms in PRCT of DCL in all kinds of dentin.

Can the Enterococcus faecalis identified in the root canals of primary teeth be a cause of failure of endodontic treatment?

OBJECTIVE: This study investigated the presence of Enterococcus faecalis in primary teeth with primary root canal infections and related to the possible failure of pulpectomy outcome after 36 months. MATERIAL AND METHODS: Root canal samples were obtained from 25 out of 244 patients using the sterile paper cone method. The identification of E. faecalis was done with culture and molecular tests using species-specific 16S rRNA gene-based polymerase chain reaction (PCR). After 36 months, the pulpectomy outcome was evaluated. RESULTS: Enterococcus faecalis was found in five (20%) samples, and dental caries were the cause of primary infection in all of them. Pulpectomy outcome was evaluated only in teeth that completed the entire clinical protocol and were followed up to 36 months (n = 8). From these, 75% (n = 6) were successful and 25% (n = 2) failed. E. faecalis was present in 50% of both successful and failed cases. CONCLUSIONS: Enterococcus faecalis was not related to the failure of endodontic treatment of primary teeth.

Antibiofilm Activity of Five Different Endodontic Filling Materials Used in Primary Teeth Using Confocal Laser Scanning Microscopy.

PURPOSE: The purpose of this study was to evaluate the effect of five endodontic materials for primary teeth on in vitro mixed-species biofilms. METHODS: Zinc oxide eugenol (ZOE) cement, Vitapex, Calen paste thickened with zinc oxide (ZO), pure calcium hydroxide (Ca(OH)2) paste, and iodoform were evaluated. Sterile water was used as a control. Mixed-species biofilm was incubated in anaerobic conditions for 21 days. The biofilm specimens were placed in contact with the endodontic materials for periods of seven and 30 days. The biofilm was studied by using confocal laser scanning microscopy. The cell viability ratio was calculated. The results were analyzed using analysis of variance and Tukey tests. RESULTS: There was a statistically significant difference between groups at both seven and 30 days (F equals 73,073, P=0.00). After 30 days, 69 percent, 51 percent, and 35 percent of the biofilm volume fluoresced red, indicating the proportion of bacteria killed by iodoform, Vitapex, and ZOE cement, respectively. Calen plus ZO and pure Ca(OH)2 paste were the least effective materials against the biofilms. CONCLUSIONS: Pure iodoform paste and iodoform containing Vitapex were the most effective materials against the biofilms. Vitapex appears to be a suitable endodontic material for primary teeth.

Microbiological, lipid and immunological profiles in children with gingivitis and type 1 diabetes mellitus.

OBJECTIVE: The aim of this study was to compare the prevalence of periodontal pathogens, systemic inflammatory mediators and lipid profiles in type 1 diabetes children (DM) with those observed in children without diabetes (NDM), both with gingivitis. MATERIAL AND METHODS: Twenty-four DM children and twenty-seven NDM controls were evaluated. The periodontal status, glycemic and lipid profiles were determined for both groups. Subgingival samples of periodontal sites were collected to determine the prevalence of periodontal microorganisms by PCR. Blood samples were collected for IL-1-ß, TNF-α and IL-6 analysis using ELISA kits. RESULTS: Periodontal conditions of DM and NDM patients were similar, without statistical differences in periodontal indices. When considering patients with gingivitis, all lipid parameters evaluated were highest in the DM group; Capnocytophaga sputigena and Capnocytophaga ochracea were more prevalent in the periodontal sites of DM children. "Red complex" bacteria were detected in few sites of DM and NDM groups. Fusobacterium nucleatum and Campylobacter rectus were frequently found in both groups. Similar levels of IL-1-ß, TNF-α and IL-6 were detected in DM and NDM children. CONCLUSION: Clinical and immunological profiles are similar between DM and NDM children. The presence of Capnocytophaga sputigena and Capnocytophaga ochracea were associated with gingivitis in DM children.

Microbiological, lipid and immunological profiles in children with gingivitis and type 1 diabetes mellitus

Abstract Objective The aim of this study was to compare the prevalence of periodontal pathogens, systemic inflammatory mediators and lipid profiles in type 1 diabetes children (DM) with those observed in children without diabetes (NDM), both with gingivitis. Material and methods Twenty-four DM children and twenty-seven NDM controls were evaluated. The periodontal status, glycemic and lipid profiles were determined for both groups. Subgingival samples of periodontal sites were collected to determine the prevalence of periodontal microorganisms by PCR. Blood samples were collected for IL-1-β, TNF-α and IL-6 analysis using ELISA kits. Results Periodontal conditions of DM and NDM patients were similar, without statistical differences in periodontal indices. When considering patients with gingivitis, all lipid parameters evaluated were highest in the DM group; Capnocytophaga sputigena and Capnocytophaga ochracea were more prevalent in the periodontal sites of DM children. “Red complex” bacteria were detected in few sites of DM and NDM groups. Fusobacterium nucleatum and Campylobacter rectus were frequently found in both groups. Similar levels of IL-1-β, TNF-α and IL-6 were detected in DM and NDM children. Conclusion Clinical and immunological profiles are similar between DM and NDM children. The presence of Capnocytophaga sputigena and Capnocytophaga ochracea were associated with gingivitis in DM children.

Role of Candida species from HIV infected children in enamel caries lesions: an in vitro study.

OBJECTIVES: This study analyzed the capacity of Candida spp. from dental biofilm of HIV infected (HIV+) children to demineralize primary molar enamel in vitro by Transversal Microhardness (TMH), Polarized Light Microscopy (PLM) and the quantity of calcium ions (Ca2+) released from the enamel. MATERIAL AND METHODS: Candida spp. samples were isolated from the supragingival biofilm of HIV+ children. A hundred and forty (140) enamel blocks were randomly assigned to six groups: biofilm formed by C. albicans (Group 1); mixed biofilm formed by C. albicans and C. tropicalis (Group 2); mixed biofilm formed by C. albicans and C. parapsilosis (Group 3); mixed biofilm formed by C. albicans, C. parapsilosis and C. glabrata (Group 4); biofilm formed by C. albicans ATCC (Group 5) and medium without Candida (Group 6). Enamel blocks from each group were removed on days 3, 5, 8 and 15 after biofilm formation to evaluate the TMH and images of enamel were analyzed by PLM. The quantity of Ca2+ released, from Groups 1 and 6, was determined using an Atomic Absorption Spectrophotometer. The SPSS program was used for statistical analysis and the significance level was 5%. RESULTS: TMH showed a gradual reduction in enamel hardness (p<0.05) from the 1st to 15th day, but mainly five days after biofilm formation in all groups. The PLM showed superficial lesions indicating an increase in porosity. C. albicans caused the release of Ca2+ into suspension during biofilm formation. CONCLUSION: Candida species from dental biofilm of HIV+ children can cause demineralization of primary enamel in vitro.

Role of Candida species from HIV infected children in enamel caries lesions: an in vitro study

Abstract Objectives This study analyzed the capacity of Candida spp. from dental biofilm of HIV infected (HIV+) children to demineralize primary molar enamel in vitro by Transversal Microhardness (TMH), Polarized Light Microscopy (PLM) and the quantity of calcium ions (Ca2+) released from the enamel. Material and Methods Candida spp. samples were isolated from the supragingival biofilm of HIV+ children. A hundred and forty (140) enamel blocks were randomly assigned to six groups: biofilm formed by C. albicans (Group 1); mixed biofilm formed by C. albicans and C. tropicalis (Group 2); mixed biofilm formed by C. albicans and C. parapsilosis (Group 3); mixed biofilm formed by C. albicans, C. parapsilosis and C. glabrata (Group 4); biofilm formed by C. albicans ATCC (Group 5) and medium without Candida (Group 6). Enamel blocks from each group were removed on days 3, 5, 8 and 15 after biofilm formation to evaluate the TMH and images of enamel were analyzed by PLM. The quantity of Ca2+ released, from Groups 1 and 6, was determined using an Atomic Absorption Spectrophotometer. The SPSS program was used for statistical analysis and the significance level was 5%. Results TMH showed a gradual reduction in enamel hardness (p<0.05) from the 1st to 15th day, but mainly five days after biofilm formation in all groups. The PLM showed superficial lesions indicating an increase in porosity. C. albicans caused the release of Ca2+ into suspension during biofilm formation. Conclusion Candida species from dental biofilm of HIV+ children can cause demineralization of primary enamel in vitro.

Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal.

This study was conducted to assess the clinical effect of photodynamic therapy (PDT) in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ - 660 nm; 40 mW; 120 J/cm2; 120 s). Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU) for any of the microorganisms assessed (p > 0.05). Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin.

Breastfeeding, Dental Biofilm Acidogenicity, and Early Childhood Caries.

AIM: This study evaluated the acidogenicity of human milk by the dental biofilms of children with and without early childhood caries (ECC). METHOD: Biofilms of 16 children (7 with ECC; 9 caries free) were exposed to human milk or 10% sucrose solution in the crossover design, and the biofilm pH was determined. RESULTS: Breastfeeding did not provoke a decrease in biofilm pH, irrespective of the children's caries status, whereas sucrose decreased the pH for both groups. In addition, higher x0394;pH5min (pH variation occurring at 5 min) was observed in the biofilms of ECC children (p < 0.05). The results suggest that breastfeeding may not contribute to ECC.

Correlation Between Bacterial Endotoxin Levels in Root Canals of Primary Teeth and the Periapical Lesion Area.

PURPOSE: The purposes of this study were (1) to assess the endotoxin levels in root canals of primary teeth with necrotic pulps and periapical lesions; and (2) to evaluate the correlation of endotoxin levels with the periapical lesion size. METHODS: Twenty primary molars with necrotic pulps and periapical lesions were selected. Standardized radiographs were obtained and the lesions were measured. Material from each root canal was collected to quantify the bacterial endotoxin. The results were analyzed using Pearson's correlation, student's t test, and Fisher's exact test (α equals five percent). RESULTS: The initial amount of bacterial endotoxin in the root canals ranged from 0.089 to greater than 50.00 endotoxin units (EU)/mL and was detected in 100 percent of the samples. A positive but not significant correlation was observed between the amount of endotoxin and periapical lesion size in primary molars. CONCLUSION: Endotoxin was observed in 100 percent of root canals of primary teeth with a periapical lesion. However, there was no statistical significance between bacterial endotoxin levels and the periapical lesion area.

Morphological Assessment and Cleaning Capacity of a Reciprocating System in Root Canals of Deciduous Teeth

Objective:To assess root canal morphological results and cleaning capacity in deciduous teeth instrumented with a reciprocating system.Material and Methods:15 deciduous molars and a total of 24 canals were selected for the study. Nine teeth(13 canals) were selected at random for microbiological analysis and 6 teeth (11 canals) were used for tomographic analysis of morphology. The roots used for the microbiological assessment were contaminated with standard strains of Enterococcus faecalis. All roots were instrumented using the WaveOne System with a Small (21:06) 21mm file and an X-Smart plus motor. Tomography was conducted with an I-CAT machine before and after instrumentation with the objective of analyzing the WaveOne System's shaping capacity. Statistics: Biostat 4.0 software was used to analyze results. The microbiological results (log10) and tomographic results (pixels) were analyzed using descriptive statistics and the Wilcoxon test.Results:There was a significant reduction in Enterococcus faecalis colony-forming units after instrumentation of the root canal systems of deciduous molars using the WaveOne system (p=0.0033) and significant enlargement of the root canal systems was observed after instrumentation (p=0.047), while morphology was maintained. Conclusion:The WaveOne System, using the Small file was effective for disinfection of the root canal systems of deciduous molars

Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal

Abstract This study was conducted to assess the clinical effect of photodynamic therapy (PDT) in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ - 660 nm; 40 mW; 120 J/cm2; 120 s). Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU) for any of the microorganisms assessed (p > 0.05). Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin.

Evaluation of the effectiveness of photodynamic therapy for the endodontic treatment of primary teeth: study protocol for a randomized controlled clinical trial.

BACKGROUND: The elimination of pathogenic microorganisms from the root canal system is one of the major steps required for successful endodontic treatment. The aim of the proposed study is to conduct a randomized, controlled, clinical trial for the clinical and radiographic evaluation of the effectiveness of photodynamic therapy during the endodontic treatment of primary teeth. METHODS: Thirty primary anterior teeth in children aged 3 to 6 years old will be randomly divided into 2 groups: a control group, which will receive conventional treatment, and an experimental group, which will be subjected to photodynamic therapy. Microbiological evaluations will be performed before and after endodontic treatment. Moreover, clinical and radiographic evaluations will be performed on the day of treatment as well as 1, 3 and 6 months after treatment. Comparisons will be made of the two study groups. The data will be tabulated and presented in a descriptive, analytical fashion. Depending on the distribution (normal or non-normal), either the t test, ANOVA or the Mann-Whitney test will be used for analysis of the variables. The Wilcoxon test will be used for comparisons before and after treatment. P values<0.05 (95% significance level) will be considered indicative of statistically significant differences. DISCUSSION: As successful endodontic treatment is directly related to intra-canal bacterial disinfection and considering the difficult task of endodontic treatment in primary teeth, often due to difficulties in controlling young children, the internal anatomy of root canals and root resorption, the alternative of using PDT is a painless,easy-to-administer method that does not lead to microbial resistance and can assist in the achievement of successful endodontic treatment in primary teeth by eliminating the pain children can experience due to retreatment as well as premature tooth loss. TRIAL REGISTRATION: The protocol for this study was registered with Clinical Trials number NCT02485210 on 30 july 2015.

Randomized in vivo evaluation of photodynamic antimicrobial chemotherapy on deciduous carious dentin.

The aim of this randomized in vivo study was to compare antimicrobial chemotherapies in primary carious dentin. Thirty-two participants ages 5 to 7 years underwent partial caries removal from deep carious dentin lesions in primary molars and were subsequently divided into three groups: control [chlorhexidine and resin-modified glass ionomer cement (RMGIC)], LEDTB [photodynamic antimicrobial chemotherapy (PACT) with light-emitting diode associated with toluidine blue solution and RMGIC], and LMB [PACT with laser associated with methylene blue solution and RMGIC]. The participants were submitted to initial clinical and radiographic examinations. Demographic features and biofilm, gingival, and DMFT/DMFS indexes were evaluated, in addition to clinical and radiographic followups at 6 and 12 months after treatments. Carious dentin was collected before and after each treatment, and the number of Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Fusobacterium nucleatum, Atopobium rimae, and total bacteria was established by quantitative polymerase chain reaction. No signs of pain or restoration failure were observed. All therapies were effective in reducing the number of microorganisms, except for S. sobrinus. No statistical differences were observed among the protocols used. All therapies may be considered as effective modern approaches to minimal intervention for the management of deep primary caries treatment.

Effect of method of caries induction on aged resin-dentin bond of primary teeth.

BACKGROUND: To investigate the influence of chemical and microbiological methods of caries induction on bond degradation of adhesive systems to primary dentin. METHODS: Flat dentin surfaces from 36 primary molars were assigned to three groups (n = 12) according to method to induce caries-affected dentin: (1) control (sound dentin); (2) pH-cycling; and (3) microbiological caries induction model. Teeth were submitted to caries induction for 14 days for both methods, and the sound dentin was stored in distilled water during the same period. Specimens from each experimental group were then randomly reassigned to two subgroups (n = 6) according to the adhesive system tested: two-step etch-and-rinse adhesive (Adper Single Bond 2 - SB) or two-step self-etch system (Clearfil SE Bond - CSEB). Composite buildups were constructed and sectioned to obtain bonded sticks to be subjected to microtensile (µTBS) testing immediately or after 12 months of water aging. The µTBS means were analyzed by three-way repeated measures ANOVA and Tukey's tests (α = 0.05). RESULTS: The µTBS values obtained to artificially-created caries-affected dentin were lower compared with sound dentin, but were not affected by method of caries induction. Water storage for 12 months reduced bond strengths, except to CSEB bonded to sound dentin. CONCLUSION: Chemical and microbiological methods affect similarly the stability of resin-dentin bonds in primary teeth.

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 (x10(5) 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.

Molecular identification and antibiotic resistant bacteria isolated from primary dentition infections.

BACKGROUND: Bacterial resistance to antibiotics is a health problem in many parts of the world. The aim of this study was to identify bacteria from dental infections and determine bacterial resistance to antibiotics used in dental care in the primary dentition. METHODS: This cross-sectional study comprised 60 children who presented for dental treatment for active dental infections in the primary dentition. Samples from dental infections were collected and bacteria were identified by polymerase chain reaction (PCR) assay. Bacterial resistance to antibiotics was determined by colony forming units on agar plates containing amoxicillin, clindamycin and amoxillicin-clavulanic acid (A-CA) tested at 8 µg/ml or 16 µg/ml. RESULTS: Clindamycin in both concentrations tested (8 µg/ml and 16 µg/ml) showed the highest bacterial resistance (85.9%), followed by amoxicillin (43.7%) and A-CA (12.0%). All comparisons among the three antibiotics used in the study exhibited statistical significance (p = <0.05) in both concentrations tested (8 µg/ml and 16 µg/ml), and under aerobic and anaerobic conditions. The most prevalent resistant species identified by PCR in primary dentition infections were: Streptococcus oralis and Prevotella intermedia (75.0%); Treponema denticola and Porphyromonas gingivalis (48.3%); Streptococcus mutans (45.0%); Campylobacter rectus; and Streptococcus salivarius (40%). CONCLUSIONS: This study demonstrated that A-CA exhibited the lowest bacterial resistance for clinical isolates in primary dentition infections.