Chlorhexidine Inhibits the Proteolytic Activity of Root and Coronal Carious Dentin in vitro.

The purpose of this study was to evaluate the effect of chlorhexidine on the proteolytic activity of carious coronal and root dentin collected from patients. Sound dentin from freshly extracted human teeth was used as a control. Dentin fragments were mixed with a synthetic substrate for proteolytic enzymes (N-benzoyl-DL-arginine-naphthylamide--BANA) and the suspensions mixed with either 0.12% chlorhexidine digluconate or distilled water. These mixtures were incubated for 18 h at 37 degrees C, color was developed by the addition of 0.1% Fast Garnet and their optical density was recorded spectrophotometrically. BANA hydrolysis measured by the optical density of incubated specimens was detected in all tested groups, but was significantly higher for carious than for sound dentin (p < 0.05). The proteolytic activity was reduced for carious coronal and root dentin by chlorhexidine (p < 0.05; 50 and 30%, respectively). Chlorhexidine also reduced the proteolytic activity in sound root dentin (p < 0.05; 20%). Conversely, changes in the proteolytic activity of sound coronal dentin were not observed in the presence of chlorhexidine. The reduction in proteolytic activity by chlorhexidine was significantly higher in carious coronal dentin than in carious root dentin (p < 0.05). In conclusion, part of the effect of chlorhexidine in controlling caries progression in humans may be due to a decrease in the proteolytic activity of carious coronal and root dentin. Because of the prolonged incubation time in the present study, similar results may be obtained clinically with prolonged dentin exposure to chlorhexidine, e.g. chlorhexidine-containing varnishes.

Longitudinal analysis of heritability for dental caries traits.

The role of genetic and environmental factors on dental caries progression in young children was determined. A detailed caries assessment was performed in 2 examinations on 314 pairs of twins initially 1.5 to 8 years old. Surface-based caries prevalence rates (SBCPR) and lesion severity (LSI) were computed. Heritability estimates were calculated by SOLAR software. Analyses were performed on all ages combined and by age group (1.5-< 4; 4-6; > 6). Overall heritability estimates (H) of net increments SBCPRs were H = 30.0 (p < 0.0001), and were greatest for the youngest (H = 30.0) and oldest groups (H = 46.3). Overall LSI heritability estimates [H = 36.1 (p < 0.0001)] were also greatest for the youngest (H = 51.2) and oldest groups (H = 50.6). Similar findings were found for net increments of occlusal surfaces and deep dentinal lesions SBCPRs (H = 46.4-56.2). These findings are consistent with a significant genetic contribution to dental caries progression and severity in both emerging primary and permanent dentitions.

Antibacterial activity of honey and propolis from Apis mellifera and Tetragonisca angustula against Staphylococcus aureus.

AIMS: The antibacterial activity against Staphylococcus aureus of honey and propolis produced by Apis mellifera and Tetragonisca angustula was evaluated. Secondary aims included the study of the chemical composition of propolis and honey samples and its relationship with antibacterial activity against S. aureus. METHODS AND RESULTS: The antibacterial activity of honey and propolis was determined by the method of macrodilution. The minimum inhibitory concentration (MICs) of A. mellifera honey ranged from 126.23 to 185.70 mg ml(-1) and of T. angustula from 142.87 to 214.33 mg ml(-1). For propolis, the MIC ranged from 0.36 to 3.65 mg ml(-1) (A. mellifera) and from 0.44 to 2.01 mg ml(-1) (T. angustula). Honey and propolis were evaluated by high-performance liquid chromatography. Some typical compounds of Brazilian propolis were also identified in honey samples. Principal component analysis revealed that the chemical composition of honey and propolis samples was distinct based on the geographical location of the samples. CONCLUSIONS: Propolis samples had higher antibacterial activity against S. aureus when compared with honey. However, both propolis and honey samples had antibacterial against S. aureus. SIGNIFICANCE AND IMPACT OF THE STUDY: These antimicrobial properties would warrant further studies on the clinical applications of propolis and honey against S. aureus.

A model for clinical evaluation of the effect of antimicrobial agents on carious dentin.

PURPOSE: To evaluate, longitudinally, the effect of a chlorhexidine varnish on the proteolytic activity of dentin caries in vivo. MATERIALS AND METHODS: 20 permanent molars and 8 primary molars with carious lesions in dentin were studied in subjects 18-35 yrs old (n=20), and 5-6 yrs old (n=8) respectively. These lesions were clinically evaluated according to texture and color. Carious dentin specimens were obtained by means of biopsies performed with a #4 carbide bur at the initial visit (TO) before application of a 10% chlorhexidine varnish and 2, 4, 8, and 12 wks thereafter. The dentin biopsies were immersed in Sorensen's buffer, vortexed for 30 s, and mixed with a 1.67 mM solution of n-benzoyl-DL-arginine-naphthylamide (BANA), a substrate for proteolytic enzymes. Samples were incubated overnight at 37 degrees C and color was developed with 0.1% fast garnet. The optical density (OD) of reaction mixtures was recorded photometrically. All teeth were grouped for analysis, as Mann-Whitney tests revealed no statistically significant differences between median values for OD for both age groups. ANOVA was used to compare progressive inhibition of proteolytic activity in dentin caries samples over time. RESULTS: The average proteolytic activity at the dentin substrates (OD) at TO and 2, 4, 8 and 12 wks thereafter were 0.794+/-0.089, 0.741+/-0.071, 0.676+/-0.087, 0.600+/-0.094, and 0.508+/-0.108 respectively. The chlorhexidine varnish mediated a significant inhibition of the proteolytic activity present in dentin caries after 12 wks (P<0.0001). At T0, 100% of the carious lesions examined were characterized as soft upon exploration. After 12 wks, 54% (15/28) of the lesions were partially hardened and 46% (13/28) hardened/nonprogressing. The dentin color was yellow/light brown in 100% of the lesions at baseline, and dark brown/black in 86% (24/28) after 12 wks. CLINICAL SIGNIFICANCE: This study demonstrated that chlorhexidine varnishes arrested active caries in vivo and inhibited the proteolytic activity present in these lesions. These findings strengthen the rationale for including chlorhexidine in the overall treatment strategy for patients with high caries activity.

Unstimulated salivary flow rates of young children.

OBJECTIVE: Studies on salivary flow rates in human beings have mainly been carried out with adults. The purpose of this study was to determine the unstimulated salivary flow rates of children 4 to 7 years old. In addition, the relative contributions of the variables age, gender, race, height, body weight, dentition status, use of prescription medication, and health status (information obtained from parents) to the unstimulated salivary flow rates of children were also studied. STUDY DESIGN: Data were obtained from children (n = 447) at 2 sites in the United States (site 1, southeast Michigan; site 2, northern Michigan) and at 5 sites in Brazil (site 3, Porto Alegre; site 4, São Paulo; site 5, Belém; and sites 6 and 7, sites in Rio de Janeiro). In northern Michigan (site 2) the participants were cognitively or developmentally disabled, or both. In Rio de Janeiro (site 7), a group of 8- to 12-year-olds served as a control group. Saliva samples were collected for 3 minutes between 9 AM and noon in the spring or summer, and the saliva rate was determined gravimetrically. Data were analyzed by analysis of variance, bivariate analysis, and regression analysis. RESULTS: The secretion rates at the 7 sites were (in milliliters per minute) 0.19 +/- 0.15, 0.23 +/- 0.28, 0.34 +/- 0.23, 0.48 +/- 0.37, 0.25 +/- 0.27, 0.37 +/- 0.28, and 0.61 +/- 0.34, respectively. There were significant differences among sites (P <.0001). The older group (site 7) had flow rates that were significantly higher than the flow rates of any other group. In addition, children from Michigan (sites 1 and 2) had significantly lower rates than most groups of children in Brazil. Girls had lower unstimulated salivary flow rates than boys did at all the sites, but the differences were not statistically significant. Race was shown not to affect the flow rates. The use of any prescription medication by children in the previous 3 months was associated with lower salivary flow rates than were found in children not using prescription medication. Children who were in good health and who had no previous medical conditions had higher flow rates--but not significantly so. Higher flow rates occurred in children with mixed dentition than in children with primary dentition, although again the differences were not statistically significant. Regression analysis revealed weight to be of significance in explaining the variability of the unstimulated salivary flow rates at 2 sites, height at 1 site, the use of prescription medication at 2 sites, and age at 1 site. CONCLUSIONS: The unstimulated salivary flow rates in children in the northern United States are comparable with those reported for Japanese children, whereas the flow rates of children in Brazil are comparable with those reported for North American and European adults. In addition, none of the demographic variables/parameters tested contributed consistently to the variability of the unstimulated salivary flow rates in children at the 7 sites assessed in this study.

Evaluation of phenolic compounds in Brazilian propolis from different geographic regions.

Chemometrics has been shown quite efficient to uncover relationships between chemical composition of a sample and its geographical origin. Forty propolis samples originated from the the South and South East of Brazil were analyzed by HPLC and 18 compounds of interest were studied which included: caffeic, p-coumaric and ferulic acids, and some of their derivatives, pinobanksin, a derivative of kaempferol and five phenolic compounds (assigned as 3-prenyl4-hydroxycinnamic acid (PHCA); 2,2-dimethyl-6-carboxyethnyl-2H-1-benzopyran (DCBE); 3,5-diprenyl-4-hydroxycinnamic acid (DHCA); compound E (still unknown) and 6-propenoic-2,2-dimethyl-8-prenyl-2H-1-benzopyran acid (DPB). Principal Component Analysis (PCA) indicated three different groups of propolis samples, having the same typical chromatogram, evaluated by HPLC. Samples from the South East group were rich in derivatives of kaempferol. Samples from the South group I had a high content of DPB compound, but a low concentration of kaempferol derivatives and of DCBEN compound. Samples from the South group II were characterized by a high concentration of DCBEN, DHCA, p-coumaric and DPB compounds. Therefore, the identification of new compounds in Brazilian propolis can give, useful information about the plant sources of a given geographic region.

Risk indicators for periodontal diseases in Guatemalan adolescents.

A random sample of sixty-two 11-15-year-old adolescents from 17 different locations in Guatemala were selected for this study. Pocket depth, Plaque Index, and bleeding upon probing were recorded from 6 randomly selected sites in each subject (a total of 372 sites). Subgingival plaque samples were subsequently collected from these sites and processed by several assays. For cost reasons, in each pair of sites different assays were performed as follows: sites #1, #2--BANA test for T. denticola, P. gingivalis, B. forsythus and screening of plaque samples with polyclonal antibodies (ELISA system) for A. actinomycetemcomitans; sites #3, #4--detection of yeasts by SAB agar; sites #5, #6--detection of Entamoeba gingivalis by the Heidenhain iron hematoxylin modified technique. A total of 66% of the children had at least one site that bled upon probing, 42% exhibited at least one site with pocket depth > 3 mm, and 79% exhibited a high Plaque Index, with the percent of sites affected being 30%, 12% and 41%, respectively. In sites #1, #2 (N = 124), the BANA test assay and A. actinomycetemcomitans tested positive in 77% and 47% of the children accounting for 59% and 31% of the sites, respectively. In sites #3, #4 (N = 124), yeasts were detected in 43% of the children and 29% of the sites. In sites #5, #6 (N = 124), Entamoeba gingivalis was detected in 21% of the children and in 11% of the sites. The risk for severe gingival inflammation and/or increased probing depth was 1.5 and 5.2 times higher if a positive BANA test or A. actinomycetemcomitans test was found in a particular site. No associations could be found for yeasts and Entamoeba gingivalis.

Avaliaçäo de fatores relacionados à transmissäo de infecçöes pelos Estreptococos do Grupo Mutans / Evaluation of factors related to the transmission of infections by the Mutans Streptococci

O objetivo deste estudo foi determinar os fatores relacionados à transmissäo de infecçöes pelos Estreptococos do Grupo Mutans (EM), dentre eles, quais as pessoas que estäo em maior contato com crianças na idade de dois a seis anos e qual é a correlaçäo dos níveis em EM existentes na saliva das crianças e seus responsáveis. Os resultados evidenciaram que säo as mäes as pessoas que ficam mais tempo com suas crianças e que existe uma similaridade bastante alta (73 por cento) entre os níveis de EM na saliva dos responsáveis e na saliva das respectivas crianças

Similarities of periodontal clinical and microbiological parameters in mother-child pairs.

The aim of this study was to verify the association between children and their mothers (N = 28) for periodontal clinical and microbiological measures. Periodontal clinical parameters (probing depth and bleeding on probing) were obtained from six reference teeth from each mother-child pair. In addition, subgingival plaque samples taken from the same reference teeth were collected and placed on the Perioscan test for the detection of Treponema denticola, Porphyromonas gingivalis and Bacteroides forsythus. There were statistically significant differences between children and mothers regarding probing depth; there was an overall tendency for mothers to exhibit average probing depths greater than their children. In contrast, if a child had a bleeding site, the respective site on the mother usually also bled on probing, implying that there was an association in terms of bleeding between the mother-child pairs. Similar findings were observed for the Perioscan test. It is concluded that the occurrence of bleeding and periodontal anaerobic infections (as determined by the Perioscan test) were similar in reference teeth of mother-child pairs. These data suggest that parents with periodontal disease may serve as a reservoir of periodontopathic organisms for their children.

Effects of a chlorhexidine varnish on the gingival status of adolescents.

The purpose of this blind study was to determine the effect of a two-stage chlorhexidine varnish, after three months, on the gingival status of 11- to 15-year-old children attending a school in Rio de Janeiro, Brazil. Subjects participating in the study were randomly allocated to control (C) and treatment (T) groups, n = 53 and n = 57, respectively. All subjects were matched at baseline on age, salivary levels of mutans streptococci, and caries scores. After elimination of carious lesions, a prophylaxis was given to both groups. The chlorhexidine varnish was then painted on the entire dentition of Group T subjects only. Prior to caries elimination, and again after three months, the gingival index was used to assess the gingival status of study subjects. An average of 106.6 +/- 8.9 and 107.7 +/- 6.2 gingival sites per subject (four sites per tooth) in Groups C and T, respectively, were examined by the same calibrated examiner on two occasions. For statistical purposes, data were dichotomized [(0,1) (2,3)] for the gingival index. Independent t-tests and paired t-tests were used to analyze the data. The percentage of sites per subject with scores of two or three at the baseline were balanced between study groups (3.7 +/- 7.1 for T; 1.8 +/- 3.2 for C; p = 0.08). After three months, a statistically significant decrease in the average percentage of sites with scores of two or three was demonstrated in the T group (0.7 +/- 2.4, T, p < 0.0001; 1.3 +/- 3.0, C, p < 0.25). The authors concluded that the application of a chlorhexidine varnish significantly improved the gingival health of T subjects for up to three months. A significant improvement in the gingival health could not be demonstrated in the C group.

Efeito de um programa näo-invasivo na progressäo da cárie dentária / The non-invasive program effect in dental carie progress

O estudo foi conduzido em uma creche na favela do Vidigal, Rio de Janeiro. Noventa e três crianças entre 5 e 7 anos de idade, as quais nunca haviam recebido nenhum tipo de tratamento operatório, foram examinadas em relaçäo ao CPO-S. As lesöes de cárie foram avaliadas quanto à sua profundidade (PLC). Um programa näo-invasivo foi iniciado, o qual consistia de escovaçäo semanal supervisionada, usando dentifrício contendo flúor e xilitol. Avaliaram-se o CPO-S e o PLC após 12 e 24 meses depois de iniciado o programa. O CPO-S näo apresentou diferença estatisticamente significativa entre o baseline e o primeiro ano. Houve, no entanto, um declínio estatisticamente significativo entre o baseline e o segundo ano (p=0.0075). Observou-se uma tendência das lesöes de cárie entre o baseline e o segundo ano, através do índice PLC, e estas observaçöes foram estatisticamente significativas (p=0.0029)

Antimicrobial action of AXOL on periodontopathic bacteria.

The antimicrobial action of AXOL was tested against a panel of periodontopathic bacteria, which included Treponema denticola, Treponema vincentii, Treponema sp., Porphyromonas gingivalis, Prevotella intermedia, Prevotella melaninogenica, and Fusobacterium nucleatum. The AXOL commercial solution (undiluted) was effective in inhibiting some of the bacteria but not all. The rational for the use of antimicrobials is discussed.

Relationship of microbial and salivary parameters with dental caries in Brazilian pre-school children.

Caries examination and collection of paraffin wax-stimulated saliva samples were performed in 37 children, 3-6 years old, in a child-care facility at the Vidigal slum, Rio de Janeiro, Brazil. The levels of mutans streptococci and lactobacilli in saliva were estimated by the Cariescreen and by the Dentocult tests and the saliva secretion rate was determined. Statistical analysis was performed on surface-based and patient-based caries prevalence rates (SBCPR and PBCPR), and related to bacterial and salivary parameters. The results show that 31 of the 37 children were caries active. The SBCPR for the primary dentition was 6.7% +/- 1.0%. Occlusal surfaces were the most affected by decay. Regression analysis revealed that mutans streptococci salivary levels were significantly associated with the SBCPR (P = 0.0001). Similarly, lactobacilli salivary levels were significantly associated with the SBCPR (P = 0.0001). No significant association could be found between the saliva secretion rate and the SBCPR. When regression analysis was used to model dependence of the SBCPR on both organisms, the mutans streptococci and lactobacilli salivary levels were significantly associated with the SBCPRs (P = 0.0021 and 0.0118, respectively), and salivary levels of these organisms accounted for 57% of the SBCPR variability. These findings indicate that the levels of mutans streptococci and lactobacilli in saliva are significantly related to the SBCPRs on the primary dentition of these children.