Adhesion of periodontal pathogens to self-ligating orthodontic brackets: An in-vivo prospective study.

INTRODUCTION: Our aims were to analyze adhesion of periodontopathogens to self-ligating brackets (Clarity-SL [CSL], Clippy-C [CC] and Damon Q [DQ]) and to identify the relationships between bacterial adhesion and oral hygiene indexes. METHODS: Central incisor brackets from the maxilla and mandible were collected from 60 patients at debonding after the plaque and gingival indexes were measured. Adhesions of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), and Tannerella forsythia (Tf) were quantitatively determined using real-time polymerase chain reactions. Factorial analysis of variance was used to analyze bacterial adhesion in relation to bracket type and jaw position. Correlation coefficients were calculated to determine the relationships between bacterial adhesion and the oral hygiene indexes. RESULTS: Total bacteria showed greater adhesion to CSL than to DQ brackets, whereas Aa, Pg, and Pi adhered more to DQ than to CSL brackets. CC brackets showed an intermediate adhesion pattern between CSL and DQ brackets, but it did not differ significantly from either bracket type. Adhesion of Fn and Tf did not differ significantly among the 3 brackets. Most bacteria were detected in greater quantities in the mandibular than in the maxillary brackets. The plaque and gingival indexes were not strongly correlated with bacterial adhesion to the brackets. CONCLUSIONS: Because Aa, Pg, and Pi adhered more to the DQ brackets in the mandibular area, orthodontic patients with periodontal problems should be carefully monitored in the mandibular incisors where the distance between the bracket and the gingiva is small, especially when DQ brackets are used.

Effect of Nd: YAG laser on the apical seal after root-end resection and MTA retrofill: a bacterial leakage study.

Laser irradiation has been investigated in terms of preventing leakage in retrofilled root canals. The aim of the present study was to evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on the bacterial leakage of mineral trioxide aggregate (MTA)-retrofilled roots. In this ex vivo experimental study, 90 single-rooted incisor teeth were filled with gutta-percha and AH26 sealer. The apical 3 mm of all the roots were resected and 3-mm retrocavities were prepared by an ultrasonic device. The specimens were randomly divided into two experimental (n = 25), one positive control (n = 10), and two negative control (n = 10) groups. In the laser + MTA group, the cavity walls were irradiated by Nd: YAG laser prior to MTA placement. In the MTA group, MTA was placed without laser irradiation. The root surfaces were covered with two layers of nail varnish except for the apical 2 mm. The specimens were then embedded in a bacterial leakage test system and examined daily for 90 days. Contamination periods were recorded. Data were analyzed by Kaplan-Meier and Mann-Whitney U tests (α = 0.05). Five teeth with and five teeth without laser irradiation underwent scanning electron microscopic evaluation. The specimens in the laser + MTA group were contaminated earlier than those in the MTA group (p < 0.05). Comparison of survival times between the two groups showed significant differences (p < 0.05). Nd: YAG laser irradiation can decrease the sealing capacity of MTA in comparison to the apical seal achieved by MTA without laser irradiation. Further studies are recommended to provide a better seal for the MTA-retrofilled teeth after laser irradiation.

Probiotics and their effect on oral bacteria count in children: a pilot study.

AIM: To assess the effect of the daily ingestion of a mixture of probiotics on the amount of Streptococcus mutans in the oral cavity of preschool-age patients with a high risk of caries. MATERIALS AND METHODS: Forty patients, aged between 4 and 6 years, with a high risk of dental caries were included in this pilot study. Patients were randomly assigned to two study groups: the Experimental Group (A) included patients who brushed their teeth and used fluoridated toothpaste in addition to consuming probiotics daily, and the Control Group (B) inclused patients who brushed their teeth and used fluoridated toothpaste but did not consume probiotics. Using the CariScreen, the microorganism count was determined at different times: baseline, 7, 14, 21 and 30 days. To identify the differences between both groups, a Mann-Whitney U test was performed, with a significance level of 0.05. RESULTS: It was observed that both groups showed similar microbial counts at the beginning of the trial (p>0.05), and a significant decrease in the count at the end of the study was found in the experimental group (p<0.05) 15 days after suspending ingestion. CONCLUSION: We found a significant reduction of RLU values in preschool children who ingested the tested probiotics in relation to the baseline values and 15 days after ceasing consumption.

[Clinical and laboratory rationale for galvanophoresis of hydroxide copper-calcium by root canals treatment].

Double blind study presents clinical and laboratory estimation of root canal system (RC) cleaning by endodontic treatment of apical periodontitis by means of galvanophoresis of hydroxide copper-calcium (GP HCC). In 60 patients the amount and composition of RC fluid from incisors and canines by GP HCC were estimated within 2 weeks with three different galvano-pair and the efficiency of RC decontamination were compared by standard report irrigation and GP HCC. The intensity of electroosmotic allocation of RC liquid by GP HCC is gradually increased at 4-5 day, and then slowly reduced at 10-12 day. The RC liquid contained proteins and carbohydrates - typical rests of pulp and biofilm. GP HCC suppresses aerobic and anaerobic microflora in RC 65.5% more effectively than standard irrigation and may be seen as an alternative method of endodontic treatment of apical periodontitis.

The effects of different orthodontic appliances upon microbial communities.

OBJECTIVES: Orthodontic appliances can promote accumulation of dental plaque, with associated enamel decalcification or gingival inflammation. The aim of this study was to examine longer-term microbiological changes during orthodontic treatment with fixed appliances. MATERIALS AND METHODS: Twenty-four orthodontic patients aged 11-14 years undergoing fixed appliance therapy were recruited into the study. Each was randomized for cross-mouth assignment of molar bands and bonded molar tubes to contralateral quadrants of the mouth. All patients received self-ligating brackets, but again using randomization, one upper lateral incisor bracket (left or right) also received an elastomeric ligature. Plaque samples from the molars and upper lateral incisors were obtained at intervals during treatment and up to 1 year after appliance removal. Denaturing gradient gel electrophoresis and 16S rDNA microarray were used to compare plaque microbial fingerprints. RESULTS: Plaque populations changed within 3 months of commencing treatment at all sites. The greatest differences in plaque composition were seen with self-ligating brackets with an elastomeric ligature. Post-treatment plaque associated with both types of molar attachment contained increased levels of periodontal pathogens Porphyromonas gingivalis, Tannerella forsythia, and Eubacterium nodatum, while Campylobacter rectus, Parvimonas micra, and Actinomyces odontolyticus were also elevated with bonds. CONCLUSIONS: The results suggest that orthodontic treatment may cause sustained changes in plaque microbiotas and that molar bond-associated plaque may have raised disease potential.

Antimicrobial activity of short- and medium-term applications of polyhexamethylene biguanide, chlorhexidine digluconate and calcium hydroxide in infected immature bovine teeth in vitro.

AIM: To compare the antimicrobial activity of polyhexamethylene biguanide (Prontosan wound gel, Pr) and chlorhexidine digluconate (CHX) after short- and medium-term application with the disinfection ability of calcium hydroxide (Ca) in a model using immature bovine teeth. METHODS: Sixty immature bovine roots were infected with Enterococcus faecalis and randomly assigned to six groups (n = 10). Disinfectants were applied into the root canal for 10 min (CHX-10 min and Pr-10 min) or 7 days (CHX-7d, Pr-7d and Ca-7d(g) ). In the negative control group (Co-n), no disinfectant was used. Dentine samples were collected, and the total count of bacteria and colony-forming units were determined. The log10 -transformed Colony-forming units (CFU) data were analysed using a Kruskal-Wallis test with post hoc Wilcoxon multiple-comparison tests. RESULTS: The application of disinfectants led to a significant reduction in CFUs in all groups compared with group Co-n. When compared to Ca-7d(g) , CHX-7d (P = 0.290), CHX-10 min (P = 0.963) and Pr-7d (P = 0.095) revealed no significant differences. Pr-10 min had a significantly higher CFU value than Ca-7d(g) (P = 0.0004), CHX-10 min (P = 0.0009) and Pr-7d (P = 0.0006). CONCLUSIONS: Within the limitations of this study, sufficient antimicrobial effect may be reached by a short-term application of CHX. For the application of 1% Prontosan wound gel, a medium-term use (7 day) is required, while short-term use (10 min) is less effective.

Changes in the supragingival microbiota surrounding brackets of upper central incisors during orthodontic treatment.

OBJECTIVE: The aim of this study was to determine how fixed orthodontic appliances affect microbiota of supragingival plaque over 5 months. MATERIALS AND METHODS: Twenty individuals of Scandinavian origin, aged 10-16 years, were included. All subjects were fitted with fixed orthodontic appliances in both the maxillary and mandibular tooth arches. Pooled supragingival plaque samples from the labial surface of the two maxillary central incisors were collected before bonding (T1) and afterwards at 4 weeks (T2), 3 months (T3) and 5 months (T4). The plaque index (PI) was recorded for each sampling. The gingival status was documented at T1 and T4 by using clinical photographs. Plaque microbiota was identified using the Human Oral Microbe Identification Microarray (HOMIM). RESULTS: Increased plaque levels were recorded after bonding, however the increase was not significant. The prevalence of gingivitis at the maxillary central incisors increased from 25% at T1 to 74% at T4. No significant changes of the plaque microbiota from the sample area were detected during the 5-month period. Trends toward a microbiota containing more periodontitis- and caries-associated bacteria were detected. CONCLUSIONS: Although trends toward a microbiota containing more periodontitis- and caries-associated bacteria were detected, the changes were not severe enough to be significant. Treatment with fixed orthodontics does not necessarily shift the microbiota to a more pathogenic composition.

Effect of clinical factors on bacterial contamination of bone chips collected during implant surgery.

PURPOSE: The objective of this study was to investigate the relationship between various clinical factors and bacterial contamination of bone chips (BC) collected during dental implant surgery and to elucidate how bacterial contamination might be minimized. MATERIALS AND METHODS: Implants were installed in 55 partially edentulous patients (36 men and 19 women), among whom the relationship between various clinical factors and bacterial contamination of BC collected by bone trap was investigated in 37. The effect of rinsing with a saline on BC was determined in 18 patients. Number of contaminating microorganisms was expressed as colony-forming units (CFUs). RESULTS: CFUs in the maxilla were lower than those in the mandible (P < 0.01). CFUs at the incisors or canines were lower than those at the premolars or molars (P < 0.01). Logistic regression analysis revealed a relationship between average bacterial count and duration of surgery (odds ratio, 1.046; 95% CI, 1.012-1.081). Rinsing of BC reduced bacterial contamination. CONCLUSION: Duration of surgery is a major clinical factor affecting contamination risk in BC, and rinsing of BC with a sterile saline solution reduces bacterial number.

Systemic consumption of probiotic curd and use of probiotic toothpaste to reduce Streptococcus mutans in plaque around orthodontic brackets.

INTRODUCTION: The objectives of the study were to evaluate and compare the effects of the systemic consumption of probiotic curd and the topical application of probiotic toothpaste on the Streptococcus mutans levels in the plaque of orthodontic patients. METHODS: The study consisted of 60 orthodontic patients divided into 3 groups of 20 each. Group 1 was the control group. The patients in group 2 were given probiotic curd, and those in group 3 were asked to brush twice daily with probiotic toothpaste (GD toothpaste; Dental Asia Manufacturing, Shah Alam, Selangor, Malaysia). Samples were collected at 2 times: before the study began and after 30 days. Plaque specimens were collected from the labial surfaces immediately surrounding the orthodontic brackets of the maxillary lateral incisors using a 4-pass technique. The presence of S mutans was evaluated using real-time polymerase chain reaction. Statistical analysis was performed, and comparisons were made using a 2-tailed chi-square test for categorical data (P <0.05). RESULTS: At the end of the study, there were reductions in S mutans concentration in groups 2 and 3 that were statistically significant compared with group 1, but there was no statistically significant difference between groups 2 and 3. CONCLUSIONS: The consumption of probiotic curd and the use of probiotic toothpaste cause a significant decrease in the S mutans levels in the plaque around brackets in orthodontic patients. Although the probiotic toothpaste was more effective than systemic consumption, this was not statistically significant.

Amplification of oral streptococcal DNA from human incisors and bite marks.

Challenges to the evidentiary value of morphometric determinations have led to a requirement for scientifically substantiated approaches to the forensic analysis of bite marks. Human teeth support genotypically distinctive populations of bacteria that could be exploited for forensic purposes. This study explored the feasibility of directly amplifying bacterial DNA from bite marks for comparison with that from teeth. Samples from self-inflicted experimental bite marks (n = 24) and human incisors were amplified by PCR using primers specific for streptococcal 16S ribosomal DNA. Amplicon profiles (resolved by denaturing gradient gel electrophoresis) from bite mark samples aligned significantly more closely with profiles generated from the teeth responsible than with those from other teeth. Streptococcal amplicons were generated from dental samples applied to excised porcine skin for up to 48 h. These findings indicate that streptococcal DNA can be amplified directly from bite marks, and have potential application in bite mark analysis.

Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

PURPOSE: Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites. MATERIALS AND METHODS: Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present. RESULTS: Two thousand three hundred two clones from the plaque of 12 patients carried bacterial sequences from 63 genera belonging to 11 phyla, including members of the uncultivable TM7, SR1, and Chloroflexi, and difficult-to-cultivate Synergistetes and Spirochaetes. Dialister invisus, Filifactor alocis, Fusobacterium nucleatum, Porphyromonas endodontalis, Prevotella denticola, Tannerella forsythia, and Treponema denticola, which have been associated with periodontal disease, were found in significantly greater abundance in pericoronal compared with incisor sites. Dialister invisus and F nucleatum were found in greater abundance in sites exhibiting clinical symptoms. The archaeal species, Methanobrevibacter oralis, which has been associated with severe periodontitis, was found in 3 symptomatic patients. CONCLUSIONS: These findings have provided new insights into the complex microbiota of pericoronitis. Several bacterial and archaeal species implicated in periodontal disease were recovered in greater incidence and abundance from the plaque of partially erupted third molars compared with incisors, supporting the hypothesis that the pericoronal region may provide a favored niche for periodontal pathogens in otherwise healthy mouths.

Quantitative molecular and culture analyses of bacterial elimination in oval-shaped root canals by a single-file instrumentation technique.

AIM: Bacterial reduction in oval-shaped root canals by a single-instrument technique was compared ex vivo with a conventional nickel-titanium rotary technique. Data obtained from two quantification methods, quantitative real-time polymerase chain reaction (qPCR) and culture, were also compared. METHODOLOGY: Oval-shaped canals of extracted teeth contaminated with Enterococcus faecalis were instrumented using either a single Reciproc instrument or the BioRaCe instrument series. Bacteriological samples were taken before (S1) and after instrumentation (S2). Bacterial quantification was performed using qPCR and culture. RESULTS: Intragroup analysis showed that both protocols promoted a highly significant bacterial reduction (P < 0.001). Intergroup analysis (S2 samples) showed no significant differences between the two instrumentation systems (P > 0.05). As for the quantification methods, qPCR revealed significantly higher counts of E. faecalis in S1 than culture (P < 0.05), but no significant differences occurred for S2 (P > 0.05). CONCLUSION: The single-file technique was comparable with the conventional technique in oval-shaped canals provided the width of apical preparation, volume of irrigants and duration of irrigation are kept similar. No significant difference was observed for qPCR and culture in post-instrumentation samples, indicating that both methods can be reliably used for studies of antibacterial effectiveness.

Biofilm retention by 3 methods of ligation on orthodontic brackets: a microbiologic and optical coherence tomography analysis.

INTRODUCTION: The aim of this study was to evaluate biofilm retention around orthodontic brackets related to the method of ligation by using optical coherence tomography (OCT) and microbiologic sampling. METHODS: Seventy-five plastic central incisors for dentures were divided into 3 groups and used with metal brackets with a 0.022-in slot with elastomeric ligature (n = 25), metal brackets with a 0.022-in slot with steel wire ligature (n = 25), and self-ligating brackets with a 0.022-in slot (n = 25). The samples were submersed in a suspension of Streptococcus mutans, genetically engineered to express green fluorescent protein, at 37°C for 72 hours to allow biofilm formation. The samples were then submitted to microbiologic analysis and OCT imaging. RESULTS: The microbiologic analysis and the OCT showed significant differences in biofilm formation depending on the ligating method. Brackets ligated with elastomeric rings held more S mutans biofilm, and steel wire ligation had less biofilm retention compared with the other brackets. CONCLUSIONS: This study provided validation that OCT can be used as a potential qualitative marker of total plaque bacteria that can be rapidly and reliably visualized around orthodontic brackets.

Molar incisor hypomineralization. Morphological and chemical aspects, onset and possible etiological factors.

UNLABELLED: OVERALL AIM: The general objective of this thesis was to enhance the understanding of Molar Incisor Hypomineralization (MIH) in areas of the histological, chemical and mechanical properties of the hypomineralized enamel, objective and subjective clinical symptoms in relation to bacteria findings. Further, to estimate a time for onset of the disturbance and investigate possible etiological factors. MATERIAL & METHODS: 22 teeth diagnosed with MIH were used in the histological and chemical studies. A number of analytical methods were used; Light microscopy, Polarized light microscopy, Scanning electron microscopy, X-ray microanalysis, Vickers hardness test and X-ray Micro Computed Tomography. Decalcified sections were stained with bacterial staining. An ozone device was tested for the ability to kill strains of oral bacteria. In collaboration with the prospective ABIS study, 17.000 individuals were examined and possible etiological causes of severe demarcated opacities were tested. RESULTS & CONCLUSIONS: The hypomineralized enamel was mainly located in the buccal enamel of the teeth and had a high degree of porosity extending from enamel-dentin-junction with a distinct border to the normal cervical enamel. Teeth diagnosed MIH had lower hardness values in hypomineralized enamel and differences in the chemical composition. Bacteria were observed in the enamel and deep into the dentin. Ozone treatment for 20 seconds or more was effective to kill oral microorganisms. Significant relations were found between MIH in first molars and breast feeding more than 6 months, late introduction to gruel and infant formula (later than 6 months). The onset for the hypomineralized enamel was estimated to around 200 days from start of the enamel mineralization.

Regional differences within the dentition for plaque, gingivitis, and anaerobic bacteria.

OBJECTIVE: This investigation assessed regional differences in dental plaque and gingivitis within the human dentition in conjunction with microbiological analyses of dental plaque. METHODS: Forty-one adults (23 males and 18 females; age range 19-44 years) were enrolled, and a calibrated dental examiner completed whole mouth examinations for dental plaque (PI) and gingivitis (GI) using the Turesky modification of the Quigley-Hein Index (TMQH) and the L6e-Silness (LS) Index, respectively. Dental plaque samples were collected from the anterior surfaces and posterior teeth to determine viable anaerobic bacteria. During this visit, subjects underwent a whole mouth dental prophylaxis and were provided a marketed fluoride dentifrice for twice-daily oral hygiene. Subjects were recalled on day 15 and day 30 for whole mouth assessments of PI and GI, followed by the collection of dental plaque from the anterior and posterior teeth for microbiological analyses during these visits. RESULTS: Low plaque and gingival scores were common on anterior surfaces, in contrast to greater frequencies of higher PI and GI scores on the posterior regions or the entire dentition. Correspondingly, mean scores for PI and GI were significantly lower among the anterior surfaces in comparison to all other regions of the mouth (posterior, Ramfjord surfaces, or the entire dentition) over each phase of the study (p < 0.0001). While prophylaxis resulted in lower clinical scores from baseline to the day-15 recall visit (p < 0.05), anterior surfaces demonstrated lower scores than posterior regions during this recall visit (p < 0.05). Although dental plaque scores increased from the day-15 to the day-30 evaluations, gingival scores maintained broad reductions, with anterior scores consistently lower than the corresponding posterior regions (p <0.05). Microbiological analyses indicated significantly lower numbers of viable bacteria from the anterior surfaces in comparison to posterior regions at both recall visits (p < 0.05). CONCLUSION: Anterior surfaces routinely demonstrated lower levels of dental plaque scores than the other regions of the dentition. Higher gingival inflammation levels were also correlated with increased plaque deposits associated with posterior teeth. Microbiological analyses confirm clinical observations with significantly higher numbers of viable bacteria in the dental plaque collected from the posterior regions. The human dentition demonstrates significant regional differences in the prevalence of dental plaque, gingivitis, and corresponding anaerobic bacteria, with posterior surfaces consistently reporting higher scores than the anterior regions. These consistent differences should be taken into account in performing plaque and gingivitis studies when assessing the efficacy of oral health products for controlling dental health.

Cariogenicity and acidogenicity of human milk, plain and sweetened bovine milk: an in vitro study.

UNLABELLED: The objective of the present study was to determine the acidogenicity and cariogenicity of human breast milk and plain and sweetened packaged bovine milk. STUDY DESIGN: First all milk specimens were inoculated with a cariogenic strain of Streptococcus mutans (SM). The culture pH and number of colony forming units (cfus) was assessed. Second, the buffer capacity of all milk specimens was evaluated by mixing with acid. Finally, enamel windows were created on extracted primary maxillary incisors and colonized with SM. Enamel demineralization and caries progression were assessed visually, histologically, and radiographically at the end of twelve weeks. RESULTS: Plain and sweetened packaged bovine milk (BM) supported greater bacterial growth and caused more fermentation than human breast milk (HBM). The buffer capacity values for plain and sweetened bovine milk were highest; HBM, however had poor buffering capacity. The progression of the carious lesions into the dentin was most severe for the sweetened bovine milk. CONCLUSIONS: HBM and plain bovine milk are relatively cariogenic in an in vitro caries model in the absence of saliva. However, supplementation with sugar exponentially enhances the cariogenic potential of the natural milk.

Microbiologic changes in subgingival plaque after removal of fixed orthodontic appliances.

OBJECTIVE: To evaluate changes that occur in the subgingival microbiota after removal of fixed orthodontic appliances using polymerase chain reaction (PCR). MATERIALS AND METHODS: Thirty orthodontic patients (11 males and 19 females; aged 20 +/- 7.3 yr) were included in this study. Subgingival plaque samplings were gathered from the disto-buccal gingival crevice of the left upper central incisors and the left lower central incisors, and from the mesio-buccal gingival crevice of the left upper first molars and the left lower first molars, at two different times: 2 weeks before appliance removal (T1), and 3 months after appliance removal (T2). DNA was extracted from the samples and the 16S rRNA-based PCR detection method was used to determine the prevalence of Actinobacillus actinomycetemcomitans , Tannerella forsythia , Campylobacter rectus , Eikenella corrodens , Porphyromonas gingivalis , Prevotella intermedia , Prevotella nigrescens , and Treponema denticola , which are considered as putative periodontopathogens. RESULTS: The frequency of positive sites at T1 and T2 was 65% and 43.3% for C. rectus , and 53.3% and 30.8% for E. corrodens , respectively. For the other bacteria, the frequency tended to be reduced between times. CONCLUSION: Periodontopathogens during orthodontic treatment were significantly reduced within 3 months of appliance removal. However, how long it takes to return to the preorthodontic composition of the subgingival microbiota and whether it happens at all remain to be seen.

Surface characteristics of orthodontic materials and their effects on adhesion of mutans streptococci.

OBJECTIVE: To test the hypothesis that there are no significant differences in the adhesion of mutans streptococci (MS) to various orthodontic materials based on their surface characteristics. MATERIALS AND METHODS: Surface roughness (SR) and surface free energy (SFE) characteristics were investigated for nine different orthodontic materials (four orthodontic adhesives, three bracket raw materials, hydroxyapatite blocks, and bovine incisors) using confocal laser scanning microscopy and sessile drop method. Each material, except the bovine incisors, was incubated with whole saliva or phosphate-buffered saline for 2 hours. Adhesion assays were performed by incubating tritium-labeled MS with each material for 3 or 6 hours. RESULTS: Orthodontic adhesives had higher SFE characteristics and lower SR than bracket materials. Orthodontic adhesives showed a higher MS retaining capacity than bracket materials, and MS adhesion to resin-modified glass ionomer and hydroxyapatite was highest. Extended incubation time increased MS adhesion, while saliva coating did not significantly influence MS adhesion. SFE, specifically its dispersive and polar components, was positively correlated with MS adhesion, irrespective of saliva coating. CONCLUSIONS: The hypothesis is rejected. This study suggests that SFE characteristics play an important role in the initial MS adhesion to orthodontic materials.

In Vitro Caries Models for the Assessment of Novel Restorative Materials.

Due to the high failure rates of traditional dental restorations, there is an ongoing effort to develop modified and new restorative biomaterials in dentistry. Being the most commonly used restorative material, most of these efforts primarily aim to improve dental composite. Generally, the main objective of such modifications is to enhance the restorative physical and antimicrobial properties in order to limit micro-leakage and inhibit bacterial biofilm cultivation. Herein, we describe the process of designing a simple in vitro model to assess the physical and antimicrobial properties of novel restorative materials in addition to evaluating their effect on the fragile balance between enamel de- and remineralization.

Anticaries effect of compounds extracted from Galla chinensis in a multispecies biofilm model.

INTRODUCTION: Galla Chinensis is a leaf gall known to have some antibacterial effects. Using an in vitro biofilm model of dental plaque, the present study aimed to evaluate the anticaries effects of Galla Chinensis and its chemical fractions. METHODS: A four-organism bacterial consortium (Streptococcus sanguis, Streptococcus mutans, Actinomyces naeslundii, Lactobacillus rhamnosus) was grown on hydroxyapatite (HA) discs, bovine enamel blocks, and glass surfaces in a continuous culture system and exposed to repeated solution pulses. Galla Chinensis extracts, sucrose solutions, and sodium fluoride solutions were pulsed into different flow cells. The pH value of the planktonic phase in each flow cell was recorded and the bacteria colonizing the biofilm on the HA discs were counted. Enamel blocks were observed using a polarized microscope and lesion depth was evaluated. The biofilm morphology was examined with a fluorescence microscope and the images captured were analyzed on an image analysis system. RESULTS: When Galla Chinensis extract, its chemical fraction, or fluoride was added to the sucrose solution, the planktonic phase pH remained higher than that in the sucrose alone. A lower level of colonization on the HA surface was also observed in the groups to which Galla Chinensis and fluoride were added compared with the control sucrose group, and this was reflected in both the total viable count and the biofilm imaging, which showed fewer cariogenic bacteria and a less compact biofilm, respectively. Enamel demineralization in both the fluoride group and the Galla Chinensis group was significantly less than that in the sucrose group. CONCLUSIONS: Galla Chinensis and fluoride may inhibit the cariogenicity of the oral biofilm. Galla Chinensis appears to be a promising source of new agents that may prevent dental caries.