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.

Microbial acid production (Clinpro Cario L-Pop) and dental caries in infants and children.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic utility of the Clinpro Cario-L-Pop test as it relates to dental caries rates and severity in infants and children. METHOD AND MATERIALS: The study population was comprised of 771 infants and children who were on average 5.2 years of age (range of 1.5 to 8 years of age). Examiners conducted dental caries clinical examination using established criteria. In addition, lesion severity was determined be measuring its depth. An indicator swab was applied to the tongue dorsum until completely moistened with saliva. The indicator swab was processed according to the manufacturer's instructions, and acid production was assessed with the aid of a color chart. RESULTS: Twenty-three percent of children were caries free, and 7% (n = 50) of participants were categorized as having low production of lactic acid (scores 1 to 3), 17% (n = 135) moderate production of lactic acid (scores 4 to 6), and 76% (n = 586) high production of lactic acid (scores 7 to 9). There was a tendency for moderate and high lactic acid formers to exhibit higher surface-based caries prevalence rates, higher rates for deep dentinal lesions, and increased lesion severity. There was a linear increase of white spot surface-based lesions from low to high lactic acid formers and for initial dentinal lesions. Clinpro Cario-L-Pop test results, when controlling for age and gender, significantly distinguished caries-free participants from those exhibiting any form of decay. CONCLUSION: These results suggest that Clinpro Cario-L-Pop test was useful in explaining elevated frequency and severity of dental caries in spite of the high levels of decay and of microbial acid production observed in this population.

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.

Mutans streptococci in preschool twins.

OBJECTIVE: The purpose of this study was to determine whether genetic factors influence variation in salivary levels of the mutans streptococci (MS) in preschool twins. DESIGN: The study population consisted of 48 pairs of monozygotic (MZ) twins and 54 pairs of dizygotic (DZ) twins. Genotyping eight highly polymorphic DNA markers determined zygosity. Demographic data and antibiotic exposure as reported by mothers were obtained by a face-to-face interview. Salivary levels of MS were determined by the Stripmutanstrade mark test. Test results are reported on a scale of 0-3. Regression analysis, two sample t-tests and structural equation modeling were applied to analyse the data. RESULTS: Only 6% of the participants ever visited a dentist (F component of the DMFS was 0 for this population). Average salivary scores for the mutans streptococci were significantly different between MZ (1.1+/-0.1) and DZ (0.8+/-0.1) twins (p=0.021). High salivary levels of MS (scores 2 and 3) were observed in 42% of MZ twins and in 26% of DZ twins. Regression analysis on the MS salivary levels revealed no significant effects of age, gender and antibiotic intake for MZ or DZ twins. The heritability of mutans streptococci colonisation in 48 pairs MZ and in 26 pairs of DZ twins was estimated to be 52%. The non-shared environment contribution was estimated to be 48%. CONCLUSIONS: These results suggest that variation in the salivary levels of the mutans streptococci is significantly contributed by genetic factors.

Xerostomia, xerogenic medications and food avoidances in selected geriatric groups.

OBJECTIVE: To study the relationship between complaints of xerostomia and salivary performance and food avoidances in four geriatric groups chosen to reflect a broad spectrum of individuals along the health-disease continuum. To determine whether xerogenic medications taken by these individuals could be associated with either complaints of xerostomia or with food avoidances. DESIGN: Cross-sectional survey. Clinical examinations and interview. SETTING: A VA dental clinic and a retirement home. PATIENTS AND OTHER PARTICIPANTS: Subjects were 529 individuals older than 56 years of age, living both in institutions and in the community (average age 70 years). Two hundred eight persons were recruited from a VA Dental Clinic, 114 from a residential retirement home, and 132 from a nursing/long-term-care facility; 75 were from an acute care ward and had a diagnosis of a cerebral vascular accident or other neurological condition. OUTCOME MEASURES: Prevalence of xerostomia, dental morbidity, salivary flow, and food avoidances. RESULTS: About 72% of the subjects experienced xerostomia sometime during the day. Stimulated salivary flow was found to be significantly lower in individuals who complained of xerostomia than in those who did not. Fifty-five percent of participants reported using one or more xerogenic medications, with an 86% prevalence in the nursing/long-term-care facility. Individuals with xerostomia had difficulty in chewing and in starting a swallow and were significantly more likely to avoid crunchy foods such as vegetables, dry foods such as bread, and sticky foods such as peanut butter in their diets. Specific medications such as the inhalants ipratropium and triamcinolone and the systemic agents oxybutynin and triazolam could be statistically associated with xerostomia and/or low salivary flow, and/or specific food avoidances. CONCLUSION: Xerostomia apparently affects the ability to chew and start a swallow. This leads to avoidance of certain foods, which raises the possibility that xerostomia could contribute to undernutrition in older persons. The topically applied ipratropium and triamcinolone and the systemic agents amitriptyline, oxybutynin and triazolam could be statistically associated with one or more complaints of xerostomia.

Characteristics of trypsin-like activity in subgingival plaque samples.

Previous studies have demonstrated that the hydrolysis of the trypsin substrate N-benzoyl-DL-arginine-2-naphthylamide (BANA), by subgingival plaque obtained from a single site, correlates best with the numbers and proportions of spirochetes in plaque samples and may serve as an indicator of clinical disease. In this investigation, we determined whether the association between BANA hydrolysis and spirochetes could be obtained in pooled subgingival plaque samples. Concomitantly, the characteristics of this reaction in terms of substrate type and concentration, microbial numbers needed to give a positive reaction as assessed by microscopic counts, rapidity of hydrolysis, and the effect of pH and various additives on the plaque BANA hydrolytic activity have been studied in pooled plaque samples from patients who were periodontally healthy or diseased. In addition, it was determined whether BANA hydrolytic activity found in subgingival plaque reflected contributions from saliva and supragingival plaque. Results indicated that the assay can best be performed with 0.67 mmol/L BANA at pH 7.0. EDTA and CaCl2 gave a slight inhibition and DTT a slight enhancement of the BANA reaction by the pooled plaque suspensions. The majority of the reactions (85%) developed their full color after overnight incubation. BANA hydrolysis was not found in saliva and occurred with much greater frequency in subgingival plaque as opposed to supragingival plaque. Analysis of the data indicated that BANA hydrolysis by pooled subgingival plaque samples is a suitable test for the detection of spirochetes when two or three spirochetes per high microscopic field are present in the sample.

Presence of Treponema denticola and Porphyromonas gingivalis in children correlated with periodontal disease of their parents.

Considerable evidence exists suggesting that periodontal disease is due to the overgrowth of a finite number of specific bacteria such as Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Treponema denticola, Bacteroides forsythus, and Prevotella intermedia, among others. Three of these organisms-P. gingivalis, T. denticola, and B. forsythus-can be easily detected in plaque samples by the hydrolysis of the synthetic trypsin substrate benzoyl-DL-arginine-naphthylamide (BANA). The aim of the present study was to determine if a relationship could be found between the presence of either these organisms of periodontitis in the parent and the presence of BANA-positive species in the child. Thirty-four mothers or fathers and 34 children were examined for plaque scores, papillary bleeding scores, and the presence of P. gingivalis and T. denticola in four subgingival or marginal gingival plaque samples as assayed by the BANA test or specific polyclonal antibodies using an ELISA. Children whose parents were colonized by BANA-positive bacteria were 9.8 times more likely to be colonized by these BANA-positive species. Children whose parents had clinical evidence of periodontitis were 12 times more likely to be colonized by these BANA-positive species. These data are compatible with the hypothesis that children may acquire the BANA-positive species from their parents, especially if the parent has periodontitis.

Detection of two anaerobic periodontopathogens in children by means of the BANA and ELISA assays.

The mouths of young children become colonized by a variety of bacteria, but there have been only a few studies that have sought the presence of periodontopathic species in this population. Almost all of these studies used culturing techniques rather than the newer detection methodologies for various periodontopathogens. Studies in adults have shown that Treponema denticola and Porphyromonas (Bacteroides) gingivalis can be detected in dental plaque by use of the BANA and ELISA diagnostic tests. In the present study, plaque samples from four subgingival sites in each of 157 children (aged from two to 18 years) were tested for BANA hydrolysis with a BANA reagent card, and for T. denticola and P. gingivalis with an ELISA assay. Anaerobic periodontopathogens hydrolyzing the BANA substrate were found to be present in at least one of four plaque samples in 88 children (56%). T. denticola and/or P. gingivalis were detected by ELISA in at least one plaque sample in each of 135 children (86%). This study shows that children are widely colonized by these micro-organisms. A higher proportion of Black children than Caucasian children was colonized by these BANA-positive organisms. Also, children having a parent with a documented history of periodontal disease were more likely to be BANA-positive than were children of parents with unknown periodontal status.

Correlation of the hydrolysis of benzoyl-arginine naphthylamide (BANA) by plaque with clinical parameters and subgingival levels of spirochetes in periodontal patients.

Recent studies have shown that the extent of hydrolysis by plaque of the trypsin substrate, N-benzoyl-DL-arginine-2-naphthylamide (BANA), correlates with the numbers and proportions of spirochetes in subgingival plaque samples, and appears to be an indicator of clinical disease. In this study, BANA hydrolysis by subgingival plaque was evaluated in a blind manner for its ability to reflect both clinical parameters and subgingival levels of bacteria and spirochetes. Subgingival plaque samples were collected from periodontally healthy and diseased sites in 23 untreated periodontal patients and in 13 treated and maintained periodontal patients. In untreated patients, BANA hydrolysis was statistically associated with the total number of spirochetes and bacteria in the plaque sample, but in the treated patients BANA hydrolysis was statistically associated only with the spirochetes. Most BANA-positive reactions in both patient groups were from the sites which were clinically diseased and high in spirochetes. The majority of the negative reactions for BANA hydrolysis in both patient groups was among the sites which were periodontally healthy and low in spirochetes. Specificity and sensitivity of the test were above 80% for disease status in untreated patients. The predictive value of a positive and negative test was above 83%. Slightly lower sensitivity, specificity, and predictive values were found in the treated group. The BANA reaction appears to be an accurate and simple indicator of both clinical disease status and plaque levels of spirochetes in individual tooth sites in untreated and treated periodontal patients.

The effects of incubation length and temperature on the specificity and sensitivity of the BANA (N-benzoyl-DL-arginine-naphthylamide) test.

A previous multi-center study examining patients diagnosed as having at least four periodontally diseased teeth showed that when BANA (N-Benzoyl-DL-Arginine-Naphthylamide) hydrolysis by periodontal pathogens such as Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus was evaluated versus clinical parameters such as clinical judgment of disease, bleeding on probing, and pocket depth, the sensitivity of the test was 84%, 82%, and 87%, respectively, while the specificity was only 42%, 41%, and 32%, respectively. The purpose of the present investigation was to improve the specificity of the test while retaining a high level of sensitivity in both gingivally healthy and periodontally diseased groups. One hundred forty-nine patients participated in this study providing 3,497 interproximal plaque samples. Gingival health was measured using the papillary bleeding score and this was compared with the presence or absence of detectable trypsin-like activity, as determined by the BANA hydrolysis of interproximal plaque samples, using a commercially-available test. Sensitivity and specificity were measured by varying the incubation time and temperature of the enzymatic assay. Using the correlated binomial model to analyze site-specific data within a patient, the specificity was highest at 35 degrees C and 5 minutes incubation (94%), and lowest at 45 degrees C and 15 minutes incubation (33%). Sensitivity was highest at 45 degrees C or 55 degrees C and 15 minutes incubation (90%) and lowest at 35 degrees C and 5 minutes incubation (47%).(ABSTRACT TRUNCATED AT 250 WORDS)

Multi-center clinical evaluation of a chairside method for detecting certain periodontopathic bacteria in periodontal disease.

The association of bacteroides gingivalis, Bacteroides forsythus, Treponema denticola, and Actinobacillus actinomycetemcomitans among others with periodontal disease offers the opportunity for the development of diagnostic tests that are based upon the detection and/or quantification of one or more of these organisms or their by-products in the plaque. Three of the putative periodontal pathogens namely, T. denticola, B. gingivalis, and B. forsythus, can hydrolyze the synthetic trypsin substrate, N-benzoyl-DL-arginine-2-naphthylamide (BANA) forming a color reaction. The present investigation evaluated a commercially developed solid state assay for BANA hydrolysis that can be read after 15 minutes incubation at chairside. A total of 702 subgingival plaque samples were collected from 117 patients seen at four university dental clinics and placed on reagent cards. The color development on the cards was compared to the presence of T. denticola and B. gingivalis in the plaque, and with the clinical appearance of the sampled sites. This multi-center study demonstrated that antibodies to B. gingivalis and T. denticola could detect these organisms by an ELISA in the majority of the subgingival plaque samples. Comparable information could be obtained when the same plaques were evaluated by the reagent card format for BANA hydrolysis. The ELISA and reagent card were comparable in their ability to distinguish between clinically healthy and diseased sites. Both diagnostic procedures detected the periodontopathogens in plaques from sites that were judged clinically healthy.(ABSTRACT TRUNCATED AT 250 WORDS)

Medication usage and dental caries outcome-related variables in HIV/AIDS patients.

The purpose of this study was to access current medication usage by HIV/AIDS patients and its effects on dental caries and on unstimulated salivary flow rates. Thirty females and 127 males (mean age = 39.6 +/- 7.4 years), of whom 46% were White/Non-Hispanic, 39% African-American, and 15% Hispanic, were examined and interviewed at the Bering Dental Clinic, Houston, Texas. The mean time in years after seroconversion was 5.4 +/- 4.1. Calibrated examiners performed dental caries examination (DMFS) with dental explorers and bitewing radiographs. Interviews were carried out with pretested questionnaires, and medication usage was assessed by illustrative examples of HIV/AIDS medications. Salivary flow rates were determined gravimetrically (mL/min). Bivariate analysis and analysis of variance (ANOVA) were used to analyze the data. Because there were no race or gender effects on dental caries outcome variables or salivary flow rates, separate logistic regression models for medication usage were generated, which were adjusted for age and CD4+ cell counts. Patients who, currently, were receiving antiretroviral therapy (ART) had a lower occurrence of dental caries than patients not taking these medications. An unexpected finding in the lower caries rate group was a decrease in salivary flow rates, which was a probable oral side effect of ART. It appears from this cross-sectional study that systemic medication for the management of HIV disease has no significant detrimental effect on the dentition.

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.

Minor salivary gland secretion in the elderly.

OBJECTIVE: Very little information exists on minor salivary gland output (MSGO) in health and disease. We investigated the minor salivary gland output of elderly subjects with different medical backgrounds and the relationship of that output with life practices, demographic variables, complaints of dry mouth, medication usage, functional status, medical treatments, and dental and medical variables. STUDY DESIGN: MSGO was measured with a special moisture-detecting paper on the lip, cheek, and palate, which comprised the total MSGO. A parsimonious linear regression model was developed to determine which of the many measured variables influenced the MSGO. RESULTS: There were significant differences in MSGO between the recruitment sites, with the non-Veteran Affairs (VA) Independent Living participants having significantly lower MSGO than the VA groups. A secretion rate for MSGO based on median values from all subjects of <4.6 microL/min was categorized as being low, whereas a secretion rate for MSGO >/=4.6 microL/min was categorized as high. A regression model was used to examine variables that could be associated with MSGO variability. The results show that being older, a woman, a current smoker, and having a complaint of dry mouth were associated with lower MSGO rates. CONCLUSIONS: An association between subjective complaints of dry mouth and a decrease in MSGO measured objectively was demonstrated in this elderly population. Furthermore, age and sex effects on MSGO were also demonstrated.

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.

Dental findings in geriatric populations with diverse medical backgrounds.

OBJECTIVE: To determine whether there is a difference in the oral/dental health in older persons with different life styles and medical status. STUDY DESIGN: Survey (cross-sectional study) included four groups: (1) subjects (n = 123) living in a residential retirement home or community dwelling; (2) subjects (n = 218) seeking dental treatment at a Veterans Affairs Dental Outpatient Clinic; (3) subjects (n = 132) resident in a VA long-term care facility; and (4) subjects (n = 81) recently admitted to a VA acute care ward with a diagnosis of cerebral vascular accident or other neurologic problem. Each subject answered questions on medical and dental health and dietary preferences in a comprehensive interview. They were given a comprehensive dental examination that included measurements of stimulated salivary flow and minor salivary gland output. RESULTS: The data from groups 2 and 3 confirmed previous reports that independent living subjects have better oral/dental health than dependent living subjects. The data from groups 1 and 4, obtained from geriatric populations on the opposite ends of the medical health/disease continuum provide new information that suggests that good medical health and good oral/dental health are linked. The subjects in group 1 were very healthy as judged by their longevity; 54% were > or = 80 years and they had low reported prevalence of medical disease. Only 6% were edentulous and the dentate persons were missing 4.5 teeth. In contrast, over 50% of the patients in group 4 were < 70 years; they had an edentulous rate of 49% and among the dentate persons had an average 12 missing and 5 decayed teeth. CONCLUSIONS: The medically healthy persons had excellent dental health whereas the sickest persons were either edentulous or had many missing teeth.

The use of a rapid enzymatic assay in the field for the detection of infections associated with adult periodontitis.

There are few objective assays for studies of the epidemiology of periodontal diseases. The PerioScan is an assay capable of detecting three periodontal pathogens, namely T. denticola, P. gingivalis, and B. forsythus, which have been associated with adult periodontitis. The PerioScan was tested in a sample of 301 Brazilians. Clinical indices--bleeding, probing depth, gingival index, and periodontal index--were recorded from four sites in each subject. Subgingival plaque samples were collected from those sites and placed on the PerioScan card. Color results were scored in the field after 15 minutes. The plaque samples were screened with polyclonal antibodies for the three species by an ELISA system. The PerioScan, when compared with the ELISA system, yields a sensitivity of 91 percent, specificity of 89 percent, and an accuracy of 90 percent. When the PerioScan was compared to clinical indices, there was a high sensitivity (at least 93%) and a low specificity (no less than 47%), with an accuracy of at least 61 percent.

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.

Preliminary report on the effects of propolis on wound healing in the dental pulp.

The purpose of this investigation was to determine the antimicrobial and healing potential of propolis on direct dental pulp exposures. This study used 25 adult male rats. Pulp exposures were performed and animals were allocated to propolis and calcium hydroxide (Ca(OH)2 groups. Animals were killed on days 5, 7, 10, and 14. The teeth were routinely processed for histological evaluation. Non-parametric tests were employed to analyze the data. No significant differences were found between study groups on the wound healing of the dental pulp. Both substances were comparable in exhibiting normal reorganization of the pulp and no increased vascularity, and were equally efficacious in maintaining a low inflammatory and microbial cell population as well as in stimulating the formation of reparative dentin.

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.