Reduction of microorganisms in carious dentin by photodynamic therapy mediated by potassium iodide added to methylene blue and red laser.

OBJECTIVE: To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model. METHODS: A microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO2). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm2), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level. RESULTS: CX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log10 for CX for all microorganisms' groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log10 for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively. CONCLUSION: aPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.

Translation and cultural adaptation of the Children's Experiences of Dental Anxiety Measure (CEDAM) to Brazilian Portuguese / Tradução, adaptação cultural e análise das propriedades psicométricas da "Children's Experiences of Dental Anxiety Measure" para uso em crianças brasileiras

Objetivo: A escala Children's Experiences of Dental Anxiety Measure (CEDAM) foi originalmente desenvolvida em Inglês para avaliar importantes aspectos da ansiedade odontológica em crianças. Os objetivos do estudo foram traduzir e realizar a adaptação cultural da CEDAM para o Português Brasileiro. Material e Métodos: A CEDAM consiste de 14 itens, medidos por escala Likert de 3 pontos, que indica a intensidade da ansiedade odontológica. O questionário foi traduzido para o Português Brasileiro, retraduzido para o Inglês, revisado por um Comitê de Especialistas e pré-testado em 10 escolares de oito a doze anos. Resultados: O Comitê Revisor de Especialistas comparou as versões original, traduzida (T1, T2) e retraduzida (BT1, BT2) e recomendou algumas mudanças a fim de obter uma boa compreensão dos itens. No pré-teste, somente a questão 8 não foi compreendida por uma criança, isto é, a versão traduzida foi bem compreendida por mais de 85% dos participantes. Conclusão: A versão brasileira da CEDAM foi culturalmente adaptada para a população avaliada de crianças.(AU)

Objective: The Children's Experiences of Dental Anxiety Measure (CEDAM) was originally developed in English to assess important aspects of dental anxiety for children. The aims of the study were to translate and perform the cultural adaptation of the CEDAM to Brazilian Portuguese. Material and Methods: The CEDAM consists of 14 items, measured by a Likert scale of 3 points, that indicates the intensity of dental anxiety. The questionnaire was translated to Brazilian Portuguese, back-translated to English, reviewed by an Expert Committee and pretested in 10 eight- to twelve-year-old schoolchildren. Results: The Expert Committee Review compared the original, translated (T1, T2) and back-translated (BT1, BT2) versions and recommended some changes in order to achieve good understanding of the items. In the pretest, only question 8 was misunderstood by one child, i.e., the translated version was well-understood by more than 85% of the participants. Conclusion: The Brazilian CEDAM was culturally adapted for the evaluated population of children(AU)

Influence of the Salivary Acquired Pellicle on the Inhibition/Progression of In Vitro Carious Dentin Treated with Silver Diamine Fluoride.

Purpose: To evaluate, in vitro, whether the presence of the acquired pellicle (AP) interferes with the effect of 38 percent silver diamine fluoride (SDF) on the inhibition or progression of carious dentin. Methods: Carious dentin specimens were divided into groups: C-no treatment control; FV-fluoride varnish; AP-acquired pellicle formation; SDF only, and APSDF-SDF plus acquired pellicle formation. After AP formation (AP and APSDF groups), all groups were subjected to pH cycling. Dentin mineral gain or loss was quantified using surface microhardness (SM). Concentrations of fluoride calcium (CaF2) and fluorapatite (FAp) fluoride retained in dentin and fluoride concentrations in de- and remineralizing solutions were determined. Results: Groups AP, FV, SDF, and APSDF showed reduced demineralization compared with the C group, but the AP group showed greater surface loss than the fluoridated groups. Groups FV, SDF, and APSDF showed greater mineral recovery than C and AP groups (P<0.05), but no differences were observed between the FV, SDF, and APSDF groups (P>0.05). The retained CaF2 and FAp were greater in the groups treated with fluoride, but there was no difference between the SDF and APSDF groups. Conclusion: The presence of the acquired pellicle reduced the progression of carious dentin lesion but did not influence its remineralization when associated with silver diamine fluoride.

CO2 laser irradiation combined with fluoridated dentifrice improved its protective effect on caries lesion progression regardless of the acidulated phosphate fluoride gel application: An in situ study.

OBJECTIVE: This in situ study aimed to investigate the efficacy of CO2 laser at a 10.6-µm wavelength combined with 1.23% acidulated phosphate fluoride (APF) and fluoridated dentifrice with 1100 µg F/g (FD) to control enamel caries progression. MATERIALS AND METHODS: Sixteen volunteers wore palatal appliances containing eight demineralized enamel specimens for four 14-day phases under sucrose exposure. These specimens were submitted to CO2 laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO2 laser, NFD + APF, NFD + CO2 laser + APF, FD, FD + CO2 laser, FD + APF, and FD + CO2 laser + APF. Mineral loss, calcium fluoride (CaF2), fluorapatite (FAp), and fluoride in the biofilm were analyzed by analysis of variance followed by the Student-Newman-Keuls test, p < 0.05. RESULTS: The highest mineral loss inhibition was noted when FD and CO2 laser irradiation were combined, which did not significantly differ from the FD + CO2 laser + APF group. The CaF2, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO2 laser irradiation promoted a slightly higher concentration of CaF2 in the enamel and F in the biofilm. CONCLUSION: Although APF promotes the high formation of CaF2 and FAp, the combined use of FD with CO2 laser overcomes the APF effect in inhibiting the progression of artificial caries-like lesions in situ. CLINICAL SIGNIFICANCE: Under the in situ design of this study, remineralization of white spot lesions was achieved through CO2 laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.

Effect of antimicrobial photodynamic therapy on the reduction of bacteria and virulence factors in teeth with primary endodontic infection.

OBJECTIVE: To evaluate the effectiveness of supplemental photodynamic therapy for improving the bacterial removal and the levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) by conducting a clinical trial. METHODOLOGY: Twenty-four root canals with pulp necrosis and periapical lesion were selected and randomly divided into conventional group using endodontic treatment with chemo-mechanical preparation (CMP) alone (n = 12) and a group using antimicrobial photodynamic therapy (aPDT) after CMP (n = 12). The samples were collected before and after CMP (conventional group) and after photodynamic therapy (aPDT group). A photosensitizer (0.005% methylene blue) was applied to the root canal for 3 minutes after CMP, whereas aPDT was performed by using a red laser with a power of 30Mw and energy density of 9J/cm2 for 90 s per root canal. Culture technique was performed to determine the bacterial colony forming units. LPS and LTA levels were quantified by using limulus amoebocyte lysate (LAL) assay and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: All samples showed growth of viable bacteria on Fastidious Anaerobe Agar (FAA), with an average of 5.19 × 105 CFU/ mL. CMP was effective in decreasing viable bacteria (p < 0.05), whereas there was a significant decrease (p < 0.05) in the samples treated with aPDT compared to those submitted to CMP. LPS and LTA were detected in all initial samples, with mean values of 20.561 EU/mL and 430.91 pg/mL, respectively. Both CMP and aPDT groups significantly decreased the levels of LPS and LTA (p < 0.05), with a statistical difference between the groups regarding aPDT (p < 0.05). CONCLUSION: Photodynamic therapy as an adjunct to CMP proved to be effective in improving root canal disinfection and reducing the LPS and LTA levels in teeth with primary endodontic infection.

Does potassium iodide help in the microbial reduction of oral microcosm biofilms after photodynamic therapy with methylene blue and red laser?

OBJECTIVE: To evaluate the efficacy of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) doped with potassium iodide (KI) against oral microcosms biofilms cultured in dentin. METHODS: A saliva-glycerol stock formed from pooled human saliva was diluted in McBain artificial saliva with 1% sucrose (1:1), inoculated on bovine dentin blocks, and refreshed daily for 5 days. The biofilms were divided (n = 9/group) and treated with 0.9% NaCl (C), 0.2% chlorhexidine (CX), 0.01% MB + low-power laser 15 J, 88 mW, 180 s (PL), and 0.01% MB + 50 mM KI + laser (PKIL). Serial dilution was performed, and cellular viability (CFU/mL) was evaluated for total microorganisms, total lactobacilli, total streptococci, and S. mutans. Additional biofilms were cultured and treated (n = 4) for biomass determination (%BMR). The microscopic structure of the biofilms was observed by SEM. One-way ANOVA and Tukey tests were conducted (α=5%). RESULTS: Total microorganisms and total streptococci significantly reduced in biofilms treated with CX and PKIL when compared to C, but the CX, PKIL, and PL treatments did not differ from each other. Total lactobacilli and S. mutans showed a significant reduction in the CX, PL, and PKIL groups when compared to C, but with no difference between them. Biomass analysis showed a significantly reduction for CX and PKIL compared to C. SEM micrographs showed noticeable changes in bacterial membrane integrity for the PKIL and CX groups. CONCLUSION: The addition of KI to methylene blue-mediated aPDT in microcosm biofilms was effective in reducing oral microorganisms, but the effect was group dependent.

Early childhood caries, obesity and anthropometric measurements: Is there a relationship?

This brief research report explored the relationship among obesity, anthropometric measurements, and early childhood caries (ECC), in 3-5 years-old children. Three hundred and ninety-one Brazilian preschoolers were given anthropometric examinations for the assessment of general, peripheral, and central adiposity, by the following measures: body mass index (BMI), hip circumference, and waist circumference. Obesity status was determined by BMI according to WHO standards. Parent's age and BMI were assessed by questionnaire, and sucrose exposure was tracked by means of a food diary. For the assessment of ECC, dental examinations were performed according to modified WHO criteria. Also, the presence of dental biofilm in maxillary incisors was detected. A direct association between BMI and ECC was found in the bivariate analysis and the best possibility of logistic regression model showed that hip circumference (HC) values ≥62 centimeters (OR = 1.63; p = 0.033) jointly with the presence of dental biofilm (OR = 2.38; p = 0.000), children's ages ≥37 months (OR = 5.09; p = 0.012), and mothers younger than 35 years (OR = 1.96; p = 0.004) were significantly connected with ECC. In conclusion, peripheral adiposity (represented by HC) in young children was in fact associated with ECC. Thus, hip circumference might be a valuable tool for exploring the relationship between caries and obesity in the early years of life.

Biofilm accumulation and sucrose rinse modulate calcium and fluoride bioavailability in the saliva of children with early childhood caries.

This study aimed at investigating the combined effect of biofilm accumulation and 20% sucrose rinse on the modulation of calcium (Ca2+), phosphate (Pi), and fluoride (F-) bioavailability in the saliva of children with early childhood caries (ECC). Fifty-six preschoolers of both genders were evaluated according to caries experience and activity: caries-free (CF, n = 28) and with ECC (n = 28) and then, submitted to biofilm intervention (biofilm accumulation). In each situation, saliva samples were collected before and five minutes after a 20% sucrose rinse to determine the concentrations of Ca2+, Pi, and F-. Calcium concentration was significantly lower in the biofilm accumulation situation compared to the situation of biofilm mechanical control (p ≤ 0.01), except for CF children after sucrose rinse. Biofilm accumulation increased salivary calcium concentration in children with ECC after sucrose rinse (p = 0.04), whereas mechanical biofilm control reduced it in both groups (p = 0.000). Phosphate concentration was influenced by mechanical control of biofilm in CF children (p = 0.03). The fluoride bioavailability was reduced by sucrose rinse and biofilm accumulation in CF and ECC children (p ≤ 0.002). In conclusion, the combined effect of biofilm accumulation and sucrose rinse modifies the bioavailability of calcium and fluoride in the saliva of children with early childhood caries.

Potassium iodide enhances inactivation of Streptococcus mutans biofilm in antimicrobial photodynamic therapy with red laser.

OBJECTIVE: To evaluate the effect of potassium iodide (KI) addition on antimicrobial photodynamic therapy (aPDT) mediated by red laser (λ = 660 nm) and methylene blue in Streptococcus mutans biofilm model. METHODS: S. mutans biofilms were cultured in 96-well plates containing BHI broth with 1% sucrose for 18 h, 10% CO2 and 37 °C and divided in groups (n = 3, in triplicate): C (NaCl 0.9%); CX (0.2% chlorhexidine); P (photosensitizer); KI (10, 25 and 50 mM); PKI (10, 25 and 50 mM); L (L1: 100 J/cm2, 9 J; L2: 200 J/cm2, 18 J); PL (photosensitizer + L1 or L2); KIL (KI at 10, 25 and 50 mM + L1 or L2); and PKIL (photosensitizer + 10, 25 and 50 mM KI + L1 or L2). Biofilms were submitted to three pre-irradiation (PI) times (5, 10, and 15 min). After the treatments, microbial counting's reduction was analyzed by Kruskal-Wallis and post-hoc Dunn's tests, respectively, and the interaction between light parameters and the PI times by two-way ANOVA (p < 0.05). RESULTS: The S. mutans viability significantly reduced in all aPDT groups, in the presence or absence of KI (p < 0.05). For all PI times, PKIL groups (10, 25, and 50 mM) significantly differed from PL groups (p < 0.05) with a reduction of 9.0 logs reached at 50 mM of KI with 15 min of PI, irradiated at 18 J. We found no significant interaction between PI time and irradiation (p > 0.05). CONCLUSION: The addition of KI to PDT mediated by methylene blue and red laser promoted an additional effect in reducing the microbial viability of S. mutans biofilm.

Debonding of orthodontic appliance changes salivary physicochemical properties and favors regression of active caries lesions: A 13-week follow-up study.

AIM: This prospective cohort study aimed to investigate whether orthodontic appliance removal (OAR) combined with caries-preventive strategies and fluoride varnish treatments alters salivary physicochemical properties, changes the activity of carbonic anhydrase VI (CA VIACT ) and α-amylase (α-AMLACT ), and favors the regression of active caries lesions (ACL). DESIGN: Twenty-two individuals aged between 13 and 24 years were assessed for the presence of visible biofilm, daily sugar exposure, caries activity, salivary flow rate (SFR), pH, buffering capacity (BC), and CA VIACT and α-AMLACT activity at baseline, and 1, 5, and 13 weeks after OAR. Variables were assessed using repeated-measures analysis of variance, Cochran's Q and McNemar's test, and Pearson's correlation. RESULTS: We observed a significant decrease in the number of ACL at the 5-week (29% reduction) and 13-week follow-ups (58% reduction). At the 5- and 13-week follow-ups, the percentage of visible biofilm and sugar exposure decreased, whereas the salivary pH and α-AMLACT activity significantly increased. BC and CA VIACT remained unchanged throughout the follow-up. CONCLUSION: OAR combined with caries-preventive strategies and fluoride varnish treatments favored the regression of ACL and increased salivary pH and α-AMLACT activity, whereas BC and CA VIACT remained stable.

The effect of photodynamic therapy on postoperative pain in teeth with primary endodontic infection.

INTRODUCTION: The objective of this study was to investigate the action of photodynamic therapy on pain control after endodontic treatment in asymptomatic teeth with a primary infection, within a single visit. METHODS: Sixty (60) single-rooted teeth with pulp necrosis and periapical lesions were selected and randomly divided into two (2) groups (n = 30), according to the protocol; a control group (CG) and a group using photodynamic therapy (aPDT). The canals were instrumented with Reciproc files # 25 up to 40 along the entire length of the canal, using 2% chlorhexidine gel as the auxiliary chemical substance, followed by irrigation with sterile saline. aPDT consited of 0.005% methylene blue as photosensitizer, using AsGaAl diode laser, 660 nm wavelength, 100 mW of power and 9 J of energy, using optical fibers with 365 µm in diameter. The canals were filled with Endomethasone N cement. RESULTS: Pain intensity was assessed at 8, 12, 24, 48, 72 h and 1 week after endodontic treatment using a visual analogue scale. The level of pain was classified as none (0), mild (1-3), moderate (4-7) or severe (8-10). The data were at a significance level of 5%. There was a statistically significant difference (p<0.05) in the periods of 8, 12, 24, 48 and 72 h between the control group and the aPDT group. After 1 week, there was no statistically significant difference. CONCLUSIONS: It is concluded that photodynamic therapy had a significant effect on decreasing post-endodontic treatment pain in teeth with necrotic pulp and asymptomatic periapical lesions.

Early Manifestation of Periodontal Disease in Children and Its Association with Familial Aggregation.

Aggressive periodontitis is a disease that causes severe destruction of periodontal tissues, showing early development and rapid progression in both primary and permanent dentitions. Due to familial aggregation, children of parents with periodontitis are considered to be at higher risk for disease occurrence, which suggests that they should be evaluated and monitored as early as possible. The purpose of this case report is to describe aspects related to early diagnosis of periodontitis in two children and their relationship with the parent's periodontal condition, exploring the familial component as a crucial factor that can lead to an early diagnosis and better clinical management in their offspring.

The role of mechanical control of biofilm in the salivary pH after sucrose exposure in children with early childhood caries.

This quasi-experimental study sought to investigate if the mechanical control of biofilm (3-times-a-day) modifies the saliva's ability to buffer the oral environment after 20% sucrose rinse (SR20%) in children with early childhood caries (ECC). Here, SR20% reduced the saliva's pH in both groups and the mechanical control of biofilm had a greater effect on this parameter after SR20% in CF children. The mechanical control of biofilm evidenced a higher buffering capacity in CF children before SR20%, which was not observed after SR20%. Otherwise, the absence of mechanical control of biofilm showed that buffering capacity was comparable in the two groups before SR20%, whereas after SR20% the saliva's buffering capacity of CF children was higher than ECC children. When biofilm was mechanically controlled, carbonic anhydrase VI activity did not change after SR20% whereas the absence of mechanical control of biofilm reduced this enzyme activity after SR20%. In conclusion, the mechanical control of biofilm did not change saliva's ability to buffer the oral environment after SR20% in children with ECC. On the other hand, CF children appeared to regulate more effectively the saliva's pH than ECC children while the absence of mechanical control of biofilm mediated their pH-modifying ability after SR20%.

Antimicrobial photodynamic therapy mediated by methylene blue coupled to ß-cyclodextrin reduces early colonizing microorganisms from the oral biofilm.

OBJECTIVE: To test the effect of antimicrobial photodynamic therapy (A-PDT) on the oral biofilm formed with early colonizing microorganisms, using the photosensitizer methylene blue coupled with ß-cyclodextrin nanoparticles and red light sources laser or LED (λ =660 nm). METHODS: The groups were divided into (n = 3, in triplicate): C (negative control, 0.9 % NaCl), CX (positive control, 0.2 % chlorhexidine), P (Photosensitizer/Nanoparticle), L (Laser), LED (light-emitting diode), LP (Laser + Photosensitizer/Nanoparticle) and LEDP (LED + Photosensitizer/Nanoparticle). A multispecies biofilm composed ofS. gordonii, S. oralis, S. mitis, and S. sanguinis was grown in microplates containing BHI supplemented with 1% sucrose (w/v) for 24 h. Light irradiations were applied with a laser at 9 J for 90 s (320 J/cm2), or with LED, at 8.1 J for 90 s (8.1 J/cm2). The microbial reduction was assessed by counting viable biofilm microorganisms in selective culture media, before and after the treatments. Data normality was assessed by the Shapiro-Wilk test, and the results were submitted to Kruskal-Wallis analysis, followed by Dunn's test, with a significance level of 5%. RESULTS: The groups LP and LEDP were able to significantly reduce the biofilm microorganism counts by as much as 4 log10 times compared to the negative control group (p < 0.05) and did not statistically differ from the positive control group (CX) (p > 0.05). CONCLUSION: The A-PDT mediated by encapsulated ß-cyclodextrin methylene blue irradiated by Laser or LED was effective in the microbial reduction of multispecies biofilm composed of early colonizing microorganisms.

Photodynamic therapy and Acyclovir in the treatment of recurrent herpes labialis: A controlled randomized clinical trial.

BACKGROUND: Herpes Simplex Virus Type 1 (HSV-1) is one of the most widespread infections that can effect the orofacial region. Recurrent infection is considered a life-long oral health problem, leading to pain, discomfort, and social restriction due to esthetic features when active. Effective therapies are needed. This study aimed to compare photodynamic therapy (PDT), Topical Acyclovir (AC), and the association of both in the healing process and self-reported symptomologies of HSV-1 recurrences. METHODS: Patients were randomly assigned into 3 groups (n = 25): PDT (low-power laser, 660 nm, 40 mW, 120 J/cm2, 4.8 J, 120 s per point) and methylene blue (0.005 %) as photosensitizer; AC (5%); PDT + AC.Data concerning lesion size, healing time, and self-reported healing parameters, such as pain, tingling, and edema were taken every day up to complete healing for all studied groups. RESULTS: There was no significant difference in healing time and pain between groups. AC group showed a significant minor reduction of the lesion compared to the AC-PDT group on day 1. Regarding edema and tingling, the comparison of treatments showed a statistical difference only on day 1, where PDT showed better results. CONCLUSION: With all the limitations of this study, it can be concluded that only on day 1 PDT showed positive effects in the treatment of herpes lesions in comparison to AC.

Relationship Between Mutans Streptococci and Lactobacilli in the Oral Cavity and Intestine of Obese and Eutrophic Children With Early Childhood Caries-Preliminary Findings of a Cross-Sectional Study.

This brief communication assessed whether there was any relationship between the counts of lactobacilli (LB) and mutans streptococci (MS) in the oral cavity and intestine of obese and eutrophic children with early childhood caries (ECC). Seventy-eight preschoolers were assigned into the following groups: 1. obese children with ECC (OECC), 2. eutrophic children with ECC (EECC), 3. obese caries-free children (OCF), and 4. eutrophic caries-free children (ECF). The diagnosis of obesity and ECC was based on the World Health Organization criteria. Dental plaque and fecal samples were collected to assess the counts of MS and LB using selective media. Data were evaluated by Poisson regression analysis, Wilcoxon test, and Sign test. Microbial indicators of ECC in obese children were MS counts in the intestine [rate ratio (RR): 4.38] and presence of LB in the oral cavity (RR: 2.12). The indicators in eutrophic children were MS levels and the presence of LB, both in the oral cavity (RR: 6.35/1.50) and intestine (RR: 2.35/2.38) (p < 0.05). The comparison between MS levels in the mouth and in the intestine revealed significant differences only in the ECF group (p = 0.04). Regarding LB presence in the mouth vs. in the intestine, except for the OCF group (p = 0.03), no other statistical differences were found. Our preliminary findings highlighted that the levels of MS and the presence of LB in the oral cavity, as well as in the lower gastrointestinal tract were associated with ECC. Moreover, obesity was found to influence this relationship.

Plaque Fluoride Levels as a Predictor of Caries Development in Early Childhood with High Sugar Exposure - A Preliminary Study.

OBJECTIVE: This longitudinal study aimed to investigate if the plaque fluoride (PF) concentration can predict the early childhood caries onset. Design: As part of a larger study, 188 preschoolers were clinically evaluated for early childhood caries diagnosis, at baseline and after 1-year follow-up. After that, the final sample comprised: 1. children who had already caries at baseline (decayed, missing or filled surfaces, as well as white chalky white spot lesions adjacent to gingival margins) and developed at least one more cavitation after one year (n=16), and 2. children who never had or developed any caries lesions, including active white spots lesions (n=15). Before the clinical examinations, dental plaque was collected. PF concentration was determined with an ion-specific electrode. A chart was used to estimate the mean daily sugar exposure. The results were statistically analyzed by Spearman correlation and logistic regression analyses (α=0.05). RESULTS: After one year, a positive significant correlation between caries development and liquid sucrose, total sugar and total sucrose consumption increments was found (p<0.05). Moreover, the solid sugar, solid sucrose and total sugar exposure at baseline were positively correlated with the presence of dental plaque at follow-up (p<0.05). To top it all, children with PF concentrations ≤0.1 µg/mg at baseline were 10 times more likely to develop caries. CONCLUSION: In conclusion, this study demonstrated for the first time in vivo that low PF concentration is a predictor of caries development in primary teeth.

A high salivary calcium concentration is a protective factor for caries development during orthodontic treatment.

BACKGROUND: This research aimed to evaluate the salivary concentrations of fluoride (F-), calcium (Ca2+), and phosphate (Pi) after brackets bonding, and to identify the role of [F-], [Ca2+], and [Pi] on the development of active caries lesion (ACL) in individuals under fixed orthodontic treatment. MATERIAL AND METHODS: A longitudinal investigation with twenty-two individuals from 11 to 22 years of age was performed in four phases (baseline and after 1, 3, and 6 months). Analyses were carried out considering the salivary concentration of [F-], [Ca2+], and [Pi], as well as the caries index. Data were analyzed using the Friedman test, followed by the Wilcoxon test and the multivariate Cox model (p≤0.05). RESULTS: 1 and 3 months after appliance bonding, the [Ca2+] was statistically lower than after 6 months (p<0.0083). On the other hand, salivary [F-] and [Pi] did not show any significant difference during the follow-up. The Cox model demonstrated that the increase of 1 µg/mL in Ca2+ decreased the risk of ACL development by 27%. In conclusion, the levels of Ca2+ changed during orthodontic treatment. CONCLUSIONS: A high Ca2+ level in the saliva is a protective factor for ACL development over time. Key words:Adolescents, bioinorganic chemistry, dental caries, orthodontic appliances.

Addition of hydrogen peroxide to methylene blue conjugated to ß-cyclodextrin in photodynamic antimicrobial chemotherapy in S. mutans biofilm.

OBJECTIVE: This study evaluated the effect of hydrogen peroxide addition on ß-cyclodextrin-conjugated methylene blue in antimicrobial photodynamic therapy(a-PDT) in S. mutans biofilm model using laser or light emitting diode (LED) (λ = 660 nm). METHODS: A preliminary assay was performed to evaluate the cytotoxicity of hydrogen peroxide in oral fibroblasts by the colorimetric method (MTT). Afterwards, groups were divided into (n = 3, in triplicate): C (negative control), CX - chlorhexidine 0.2% (positive control), P (methylene blue/ß-cyclodextrin), H (Hydrogen Peroxide at 40 µM), PH, L (Laser), LP, LH (Laser+Hydrogen Peroxide), LPH, LED, LEDP, LEDH, and LEDPH. The biofilm was formed in 24 h with BHI + 1% sucrose (w/v). Light irradiations were conducted with laser, 9 J, 323 J/cm2, 113 s or with LED, 8.1 J, 8.1 J/cm2 for 90 s. Microbial reduction was evaluated by counting the viable microorganisms of the biofilm after the respective treatments, in a selective culture medium, and laser confocal microscopy evaluation. RESULTS: LP, LH, LPH, LEDP, LEDH, and LEDPH groups statistically reduced the counts of S.mutans compared with the C group and the log reductions were of 1.87, 1.94, 2.19, 0.91, 0.92, and 1.33, respectively; the addition of hydrogen peroxide did not potentiate the microbial reductions (LPH and LEDPH) compared with the LP and LEDP groups. CONCLUSION: The association of hydrogen peroxide with the conjugated ß-cyclodextrin nanoparticle as photosensitizer did not result in an enhanced effect of a-PDT; hydrogen peroxide behaved as a photosensitizer, since it reduced the number of S. mutans when associated with laser light.

Combined Effectiveness of ß-Cyclodextrin Nanoparticles in Photodynamic Antimicrobial Chemotherapy on In Vitro Oral Biofilms.

Objective: This study aimed to investigate if ß-cyclodextrin nanoparticles potentiate the photodynamic antimicrobial chemotherapy (PACT) effects in single and microcosm oral biofilms using methylene blue (MB) and a red laser. Background data: Studies of PACT have demonstrated promising effects; however, the association of nanoparticles with photosensitizers could enhance the antimicrobial result. Materials and methods: Biofilms were grown on enamel blocks either with Streptococcus mutans or in a microcosm model (salivary microorganisms) supplemented with sucrose. PACT using 50 µM MB associated or not with 32 µM encapsulated ß-cyclodextrin with MB for 5 min, followed by irradiation with red laser (λ = 660 nm, 320 J/cm2), was conducted and the counts of viable microorganisms in proper selective media were determined. Data were analyzed by one-factor ANOVA, followed by Tukey's test, or Kruskal-Wallis test, followed by Dunn's post hoc test, all with a significance level of 5%. Results: In the single-species biofilm model, a significant reduction in S. mutans counts was found for all groups when light was present. In the microcosm biofilm model, no significant difference was found among the groups for total streptococci, but a significant reduction of S. mutans was observed for the PACT group of encapsulated ß-cyclodextrin+MB. However, no statistically significant difference was observed among the PACT groups. Conclusions: PACT with ß-cyclodextrin mediated with MB associated with a red laser reduced S. mutans in microcosm biofilms. However, the presence of ß-cyclodextrin nanoparticles did not potentiate the PACT effects in single or microcosm oral biofilms.