Subsequent Caries Research Articles

Subtypes of early childhood caries predict future caries experience.

To test whether postulated subtypes of early childhood caries (ECC) are predictive of subsequent caries experience in a population-based cohort of Swedish children. The study included children aged between 3 and 5 years at study entry with dental records available for at least 5 years of follow-up. Dental record data were retrieved from the Swedish Quality Registry for Caries and Periodontal disease (SKaPa) for the initial and follow-up visits. Participants who had ECC at study entry were assigned to one of five ECC subtypes (termed classes 1-5) using latent class modelling of tooth surface-level caries experience. Subsequent experience of caries was assessed using the decayed, missing and filled surfaces indices (dmfs/DMFS) at follow-up visits, and compared between ECC subtypes using logistic and negative binomial regression modelling. The study included 128 355 children who had 3 or more dental visits spanning at least 5 years post-baseline. Of these children, 31 919 had caries at the initial visit. Baseline ECC subtype was associated with differences in subsequent disease experience. As an example, 83% of children who had a severe form of ECC at age 5 went on to have caries in the permanent dentition by the end of the study, compared to 51% of children who were caries-free at age 5 (adjusted odds ratio of 4.9 for new disease at their third follow-up). ECC subtypes assigned at a baseline visit are associated with differences in subsequent caries experience in both primary and permanent teeth. This suggests that the development and future validation of an ECC classification can be used in addition to current prediction tools to help identify children at high risk of developing new caries lesions throughout childhood and adolescence.

Age of First Oral Health Examination and Dental Treatment Needs of Medicaid-Enrolled Children.

Early childhood caries (ECC), despite being preventable, remains the most prevalent disease of childhood, particularly in children between the ages of 2 and 5 y. The association between the type of health care provider completing initial oral health examinations and subsequent dental caries in children under 6 y of age is unclear. The objective of the current study is to longitudinally assess the association between age at first oral health examination and provider type at first oral health examination on dental treatment for children under 6 y of age. Deidentified administrative claims data were used from the IBM Marketscan Multi-State Medicaid Database (n = 2.41 million Medicaid-enrolled children younger than 6 y in 13 states from 2012 to 2017). A Kaplan-Meier survival analysis was used to examine the association between age at first oral health examination and provider type with first treatment of dental caries at follow-up. The adjusted hazard ratio (HR) of dental caries for children whose first oral health examination at 4 y of age is 5.425 times higher than for children whose first oral health examination was before 1 y of age (95% confidence interval [CI], 5.371-5.479). The adjusted HR of dental caries for children seen by pediatric dentists (HR = 1.215; 95% CI, 1.207-1.223) and physicians (HR = 2.618; 95% CI, 2.601-2.635) was higher than those seen by a general dentist. Findings from this study highlight the importance of children having their first oral health examination no later than 12 mo of age in accordance with existing guidelines and referrals from physicians to prevent the need for invasive treatment. Results of this study emphasize the need for a child's first oral health examination to be completed no later than 12 mo of age to prevent dental caries. Reinforcement and referrals by physicians based on this recommendation facilitate early establishment of a dental home in young children.

The vicK gene of Streptococcus mutans mediates its cariogenicity via exopolysaccharides metabolism

Streptococcus mutans (S. mutans) is generally regarded as a major contributor to dental caries because of its ability to synthesize extracellular polysaccharides (EPS) that aid in the formation of plaque biofilm. The VicRKX system of S. mutans plays an important role in biofilm formation. The aim of this study was to investigate the effects of vicK gene on specific characteristics of EPS in S. mutans biofilm. We constructed single-species biofilms formed by different mutants of vicK gene. Production and distribution of EPS were detected through atomic force microscopy, scanning electron microscopy and confocal laser scanning microscopy. Microcosmic structures of EPS were analyzed by gel permeation chromatography and gas chromatography-mass spectrometry. Cariogenicity of the vicK mutant was assessed in a specific pathogen-free rat model. Transcriptional levels of cariogenicity-associated genes were confirmed by quantitative real-time polymerase chain reaction. The results showed that deletion of vicK gene suppressed biofilm formation as well as EPS production, and EPS were synthesized mostly around the cells. Molecular weight and monosaccharide components underwent evident alterations. Biofilms formed in vivo were sparse and contributed a decreased degree of caries. Moreover, expressional levels of genes related to EPS synthesis were down-regulated, except for gtfB. Our report demonstrates that vicK gene enhances biofilm formation and subsequent caries development. And this may due to its regulations on EPS metabolism, like synthesis or microcosmic features of EPS. This study suggests that vicK gene and EPS can be considered as promising targets to modulate dental caries.

Prevalence of Canal Variations in Mandibular 1st Molar in South Indian Population and Association with Age and Gender

Mandibular first molars are amongst the most common teeth requiring endodontic treatment due to their early emergence in the oral cavity and subsequent caries. Proper knowledge and understanding of the root canal morphology and anatomy of mandibular first molars, will help the clinician in developing a proper and standard treatment protocol by predicting possible variations that potentially challenge the treatment outcome. The main objective of the present study was to know the prevalence of canal variations in mandibular 1st molar among the South Indian population and its association with age and gender. All the patients who reported during June 2019 to March 2020 for mandibular 1st molar endodontic therapy were chosen for the study. Information was collected from the dental hospital record system and the resulting data was tabulated in excel and imported to SPSS for correlation and association. Within the limits of the study, the results obtained are: prevalence of canal variations is 7.6% and 2.2% in single and multi visit root canal treatment respectively with a higher incidence among the male patients and it is primarily seen in the age group of 21 to 40 years. This knowledge about the canal variations in the South Indian population will be helpful to the clinician to look for any unusual anatomy while performing endodontic therapy which will prevent any unwanted procedural errors. It necessitates the careful negotiation and cleaning of all accessible canal spaces.

Dental anxiety and caries experience from late childhood through adolescence to early adulthood.

To assess the association between dental anxiety and caries experience from late childhood through adolescence and into early adulthood (12, 15 and 18 years old, respectively). A prospective cohort study was conducted among a population-representative sample of Chinese in Hong Kong. A baseline survey was conducted at age 12 and follow-up assessments were completed at ages 15 and 18. Caries experience was assessed as the number of decayed, missing and filled teeth (DMFT). Dental anxiety was assessed using the Modified Dental Anxiety Scale (MDAS). Participants' socio-economic status and oral health-related behaviours were ascertained using a self-complete questionnaire. Negative binomial regression was used to explore the association between dental anxiety and subsequent caries status, controlling for other factors. At baseline, 668 children participated; 279 (41.8%, comprising 57.0% females) completed all three phases of data collection. MDAS scores at age 18 were lower than at age 12. Caries experience increased as participants aged. At age 15 and 18, females had higher MDAS and DMFT scores than males. Reported frequency of snacking between meals was associated with MDAS scores at age 18. In regression analyses, dental anxiety at age 12 was not significantly associated with dental caries experience at age 15, controlling for socio-demographic and oral-health behaviour factors at age 12. Likewise, dental anxiety at age 15 was not significantly associated with dental caries experience at age 18, controlling for the same factors at age 15. Dental anxiety assessed by MDAS in late childhood and adolescence appears not to predict dental caries experience later in life in this population.

Prevalence of Iron Deficiency Anemia in Children with Severe Early Childhood Caries

Dental caries is an international public health challenge, especially amongst young children. Early childhood caries (ECC) is a serious public health problem in both developing and industrialised countries. ECC can begin early in life, progresses rapidly in those who are at high risk, and often goes untreated. Its consequences can affect the immediate and long-term quality of life of the child's family and can have significant social and economic consequences beyond the immediate family as well. ECC can be a particularly virulent form of caries, beginning soon after dental eruption, developing on smooth surfaces, progressing rapidly, and having a lasting detrimental impact on the dentition. Children experiencing caries as infants or toddlers have a much greater probability of subsequent caries in both the primary and permanent dentitions. Iron deficiency being the most common nutritional deficiency in childhood is often seen associated with severe caries destruction. Lack of iron is one of the most common dietary deficiency observed worldwide particularly in developing countries. In some instances this deficiency is alleviated by supplementary foods with added iron salts. In many countries where the iron deficiency is apparent, the prevalence of dental caries is high.

Dental treatment under general anesthesia in adults with special needs at the University Hospital of Dental Prosthetics and Restorative Dentistry of Innsbruck, Austria: a retrospective study of 12\xa0years

ObjectivesSpecial needs patients are prone to insufficient oral care and subsequent caries or periodontitis. The aim of this retrospective study was the assessment of demand for restorative therapy and tooth extractions under general anesthesia in adults with intellectual and/or physical disablement (IPD) or psychiatric disorders (PDs) with inherent dentist phobia at the University Hospital of Innsbruck with regard to demographic factors.Materials and methodsA total of 444 consecutive cases of scheduled dental general anesthesia (DGA) in adults from 2003 to 2014 were included. From patient files, demographic data, the presence of either IPD or a PD, attested by a mandatory certificate, and restorative therapy and tooth extractions performed under DGA were obtained. Data analysis was carried out by means of descriptive and comparative statistics.ResultsFour hundred two cases (mean age 37.5 ± 13.87 years) assigned to 283 individuals with IPD and 42 cases (mean age 36.09 ± 13.03 years) assigned to 39 individuals with PDs arose in the observed period. Patients with PDs required significantly more restorations (in 7.98 ± 5.4 versus 5.34 ± 4.41 teeth; p = 0.002; Mann-Whitney U test) and extractions (of 4.86 ± 4.51 versus 2.6 ± 3.96 teeth; p < 0.001; Mann-Whitney U test) than patients with IPD.ConclusionsDemand for dental treatment was high in the collective of special needs patients. Oral health status was worse in patients with PDs than in patients suffering IPD.Clinical relevanceWhile in patients with severe disablement, DGA presents the only treatment option, specific preventive programs should be implemented for patients with minor disablement or dentist phobia. In these patients, alternative approaches should be promoted.

Knowledge, Attitude, and Practices of Dental Practitioners in Thiruvananthapuram on Oral Health Care for Children with Special Needs.

ABSTRACTThe objective of this study was to investigate knowledge, attitude, and practices of dental practitioners in Thiruvananthapuram, India regarding dental management of children with special healthcare needs (CSHCN).Materials and methodsA structured questionnaire was given to 400 dental practitioners. The data were analyzed using SPSS software (version 23.0) and Chi-square test was used.ResultsThe response rate was 94%. An estimated 73.8% treated children, 66.5% showed willingness to treat CSHCN, and 70.8% had attended CSHCN in their practice. A partial knowledge in dental management of CSHCN was reported by 67.5%. An estimated 36% had undergone training in special care dentistry (SCD) but 45% were not sure whether they can provide dental care with the graduate-level training. Knowledge regarding guidelines for CSHCN was known to 19.5% and that regarding timing of the first dental visit was known to 69% of participants. Tooth extraction (43.1%) and a subsequent caries treatment (39.1%) were the most frequently done procedures, and nonpharmacological management (46.5%) was the mostly used behavior management technique. Among the barriers faced by dentists in treating CSHCN, time consumption (55.6%) and lack of training (55.1%) were commonly enlisted. Further training and improved facilities would motivate the respondents in providing better care to CSHCN.ConclusionThis study suggests that majority of the dentists participated had a partial knowledge on SCD and were willing to treat CSHCN. Insufficient training in the field of SCD was a major drawback, which prevented most general dentists from effectively managing CSHCN. Additional training and improving facilities can improve dental care to CSHCN.How to cite this articleRajan S, Kuriakose S, et al. Knowledge, Attitude, and Practices of Dental Practitioners in Thiruvananthapuram on Oral Health Care for Children with Special Needs. Int J Clin Pediatr Dent 2019;12(4):251–254.

Horizontal transmission of Streptococcus mutans in children attending kindergarten

Background: Transmission of Streptococcus mutans (S. mutans), the main pathogen found in dental caries, is particularly prevalent during the first two years of infancy. Numerous children are reportedly infected with S. mutans by their mothers with early initial acquisition of the condition considered to carry a higher risk of subsequent dental caries. Purpose: This research aimed to examine the possibility of horizontal transmission of S. mutans in children attending Surabaya-based kindergartens. Methods: The number of subjects who satisfied the inclusion criteria totaled 146. Dental plaque was collected for one minute with a sterile toothbrush. After completion of an isolation process, 25 S. mutans colonies were identified in Tripticase Cysteine Yeast (TYC) media by means of morphological, microscopic and biochemical tests using API 20 Strept (bioMerieux France). A polymerase chain reaction with OPA-2 and 13 was subsequently used to determine the genotype of S. mutans. Primary data collection was completed by the administering of a questionnaire intended to elicit information regarding the gender, age, diet and medical history of subjects. Results: An arbitrarily primed polymerase chain reaction (AP-PCR) fingerprint profile of the strains isolated from the subjects indicated similarities in five genotypes of S. mutans and differences in 18 genotypes. Conclusion: The study indicated that certain children are similarly infected by S mutans bacteria which might be due to horizontal transmission between classmates.

Prevention of Enamel Adjacent to Bracket Demineralization Following Carbon Dioxide Laser Radiation and Titanium Tetra Fluoride Solution Treatment: An In Vitro Study.

Introduction: The aim of this study was to assess the caries-preventive potential of carbon dioxide (CO2) laser application in conjunction with the use of titanium tetra fluoride solution on the enamel adjacent to bracket. Methods: Seventy-five freshly extracted bovine incisors were used. In order to attach the brackets, the area of examination was covered with adhesive tape to limit acid etching of the entire enamel surface. Metal orthodontic brackets for upper central were bonded to all the teeth following the manufacturer's instruction. Then all the teeth were painted with 2 layers of acid-resistant nail varnish on all surfaces except the boxes area cervical to the brackets. The teeth were then randomly divided into five groups (n = 15): control group (C); laser group (L); titanium group (T); laser-titanium group (LT) and titanium-laser group (TL). The laser-titanium group was first irradiated with CO2 laser (same as the L group) then TiF4 solution was applied on the enamel (same as the T group). Samples in the TL group were first treated with TiF4 solution (same as the T group) and then irradiated with CO2 laser on the surface (same as the L group). Then, the teeth were immersed in pH-cycling solutions. After that, the amount of calcium released into the two solutions (de- and re-mineralization) was measured with an atomic absorption spectroscopy. The data were analyzed by one-way Analysis of var-iance (ANOVA) and Tukey test. Results: Calcium loss in LT, TL and T groups were significantly lower than those in the L and C groups (P < 0.05). Conclusion: The application of Titanium tetra fluoride 4% solution on enamel can inhibit as much as 87% of subsequent caries like lesion progression.

Identification of anti-biofilm components in Withania somnifera and their effect on virulence of Streptococcus mutans biofilms.

The aim of this study was to identify components of the Withania somnifera that could show anti-virulence activity against Streptococcus mutans biofilms. The anti-acidogenic activity of fractions separated from W. somnifera was compared, and then the most active anti-acidogenic fraction was chemically characterized using gas chromatography-mass spectroscopy. The effect of the identified components on the acidogenicity, aciduricity and extracellular polymeric substances (EPS) formation of S. mutans UA159 biofilms was evaluated. The change in accumulation and acidogenicity of S. mutans UA159 biofilms by periodic treatments (10 min per treatment) with the identified components was also investigated. Of the fractions, n-hexane fraction showed the strongest anti-acidogenic activity and was mainly composed of palmitic, linoleic and oleic acids. Of the identified components, linoleic and oleic acids strongly affected the acid production rate, F-ATPase activity and EPS formation of the biofilms. Periodic treatment with linoleic and oleic acids during biofilm formation also inhibited the biofilm accumulation and acid production rate of the biofilms without killing the biofilm bacteria. These results suggest that linoleic and oleic acids may be effective agents for restraining virulence of S. mutans biofilms. Linoleic and oleic acids may be promising agents for controlling virulence of cariogenic biofilms and subsequent dental caries formation.

Early childhood caries update: A review of causes, diagnoses, and treatments

Dental caries (decay) is an international public health challenge, especially amongst young children. Early childhood caries (ECC) is a serious public health problem in both developing and industrialized countries. ECC can begin early in life, progresses rapidly in those who are at high risk, and often goes untreated. Its consequences can affect the immediate and long-term quality of life of the child's family and can have significant social and economic consequences beyond the immediate family as well. ECC can be a particularly virulent form of caries, beginning soon after dental eruption, developing on smooth surfaces, progressing rapidly, and having a lasting detrimental impact on the dentition. Children experiencing caries as infants or toddlers have a much greater probability of subsequent caries in both the primary and permanent dentitions. The relationship between breastfeeding and ECC is likely to be complex and confounded by many biological variables, such as mutans streptococci, enamel hypoplasia, intake of sugars, as well as social variables, such as parental education and socioeconomic status, which may affect oral health. Unlike other infectious diseases, tooth decay is not self-limiting. Decayed teeth require professional treatment to remove infection and restore tooth function. In this review, we give detailed information about ECC, from its diagnosis to management.

Streptococcus salivarius meningitis after dental care: case report

Introduction. Streptococcus salivarius is a common commensal of the oral mucosa, associated with infections in different sites. Meningitis due to this species are described in a few occasions . In this study refer to a case recently diagnosed in our hospital for treatment of a subsequent dental caries. Case report. A man of 35 years, presents to the emergency room with fever, headache, confusion, marked nuchal rigor.Anamnesis is the treatment of dental caries on the previous day.The blood count showed 24.7x109 / L with WBC 22.9x109 / L (92.9%) neutrophils. The lumbar puncture CSF noted cloudy with 15.0 x 109 / L WBC, glicorrachia 5 g / L, protidorrachia 6.5 g / L. Microscopic examination showed numerous granulocytes and prevalence of Gram-positive cocci.The pneumococcal antigen was negative.The blood cultures before starting antibiotic therapy, were negative. CSF was isolated from the culture of a Streptococcus salivarius. To antibiotic therapy started in the ED, after lumbar puncture is associated with the Ampicillin Ceftriaxone and continued for 15 days to improve the patient’s general condition, then resigned in the 17 th day. Materials and methods. From CSF inoculated in blood agar plates and chocolate agar alpha hemolytic colonies were isolated, catalysis negative, optochin resistant. The biochemical identification performed with Phoenix (BD) and confirmed by PCR Pan bacterial (16S rDNA) bacterial strain identified as Streptococcus salivarius.The antibiogram performed with Phoenix (BD) according to the CLSI guidelines indicated sensitivity to penicillin, vancomycin, cefotaxime, cefepime, and chloramphenicol. Conclusions. Meningitis by Streptococcus salivarius was found in a few cases, mainly related to the transmission of health personnel from the oral cavity during lumbar punctures performed without the use of surgical masks. The following bacterial meningitis in dental treatment having a low incidence and often fatal course be suspected by history.The patient should be further investigated because the infection may indicate a compromised immune unknown (Diabetes, HIV...).

PS24 Nutritional Status in Relation to Caries Experience Among Primary School Iraqi Children in the Middle Region of Iraq

BackgroundMalnutrition when occurs during development period may cause irreversible effect on developing dental tissues leading to dental caries. The aims of the present study were to evaluate the nutritional status...

Clinical Evidence for Polyol Efficacy

Xylitol is a safe dental caries preventive when incorporated into chewing gum or confections used habitually. The goal of this paper is to identify and assess the work on xylitol and other polyols and dental caries since 2008. Xylitol is effective when used by the mother prenatally or after delivery to prevent mutans transmission and subsequent dental caries in the offspring. One new completed trial confirmed that children of mothers who used xylitol lozenges after delivery had less dental caries than a comparison group. A similar study confirmed that the use of xylitol gum by the mother either prevented or postponed MS transmission to the offspring. Xylitol use among schoolchildren delivered via a gummy bear confection reduced S. mutans levels, but a once per day use of xylitol-containing toothpaste did not. Randomized trials, with caries outcomes, assessing xylitol-containing lozenges in adults and xylitol-containing gummy bears in children will release results in the coming year. Other studies are ongoing but are not systematic and will fail to answer important questions about how xylitol, or other polyols, can address the global dental caries problem.

Vaccine against Dental Caries- An Urgent Need

Dental caries, the disease that causes tooth decay, is infectious, and the mutans streptococci bacteria have long been identified as the primary disease-causing agents. Most treatments are now aimed at either elimination of this bacterium or suppression of its virulence. Thanks to numerous scientific advances, tooth decay is not as rampant as it once was, but it is still five times more common in children than asthma and seven times more common than hay fever. And about 25% of the population (in the United States) carries about 80% of the disease burden. So it is still a serious problem, especially for those populations who are very young, very old, economically disadvantaged, chronically ill, or institutionalized. Contemporary research is aimed at evolving a potent and effective caries vaccine to prevent dental caries. Various experimental trials have been conducted utilizing rat and primate models with protein antigens derived from S. mutans or S. sobrinus to prevent oral colonization by S. mutans and subsequent dental caries. Numerous strategies have been developed to induce high levels of salivary antibodies that can persist for prolonged periods and to establish immune memory by through different routes of administration. Therefore elimination of caries is the main objective of the health professionals. Still more clinical trials are needed to evaluate the safety of these vaccines so that potential risks are eliminated.

Isolation of Dental Caries Bacteria from Dental Plaque and Effect of Tooth Pastes on Acidogenic Bacteria

Destruction of calcified tissue was caused by acids which are by product of carbohydrate metabolism of acidogenic bacteria consequent to dental caries. The purpose of this study was to assess the existence of acidogens potentially causing the dental caries and comparatively evaluation of efficacy of different toothpastes. The dental plaques of fifty persons belong to three age groups (1 - 20, 21 - 40, 41 - 60 year and above) were examined to identify microorganisms by the culture method. Thirty nine bacteria were isolated by spread plate method on BSMY I minimal media. Thirteen out of thirty nine, acidogens colonized in the dental plaques. Seven potentially acidogens CD17, CD26, CD27, CD28, CD29, CD34 and CD35 were treated with five different toothpastes. Inhibition effect of Triclosan and Fluoride containing tooth pastes were found more efficient. The results of the present study revealed that bacteria that commonly cause dental caries colonized in dental plaques of children and alcoholic person. Therefore, dental plaques must be considered a specific reservoir of colonization and subsequent dental caries. To reduce the dental problem triclosan and fluoride containing product should be recommended.

Glycan-binding specificities of Streptococcus mutans and Streptococcus sobrinus lectin-like adhesins

Since the adhesion of bacteria to the tooth surface is a prerequisite for dental plaque and subsequent caries development, a promising caries preventive strategy could be to block the lectin-glycan-mediated adherence of cariogenic bacteria. The aim of the study was to evaluate potential differences in glycan-binding specificities of two Streptococcus mutans strains (DSM 20523 and DSM 6178) and Streptococcus sobrinus (DSM 20381). A competitive enzyme-linked lectin-binding assay was used to identify the binding specificities of isolated bacterial surface lectins. Blotting of the microbial proteins on neoglycoprotein-coated PVP membranes enabled a qualitative protein analysis of all specific bacterial lectins. Different glycan-binding sites could be identified for the S. mutans strains in comparison to S. sobrinus. An earlier reported glycan-binding specificity for terminal galactose residues could be confirmed for the S. mutans strains. For the S. sobrinus strain, more than one glycan-binding specificity could be found (oligomannose and terminal sialyl residues). Each of the tested strains showed more than one surface lectin responsible for the specific lectin-binding with varying molecular weight (S. mutans, 90/155 kDa and S. sobrinus, 35/45 kDa). The established experimental setup could be used as future standard procedure for the identification of bacterial lectin-derived binding specificities. The findings from this study might serve as basis for the design of an individual 'glycan cocktail' for the competitive inhibition of lectin-mediated adhesion of mutans streptococci to oral surfaces.

Correlation of Osteoradionecrosis and Dental Events With Dosimetric Parameters in Intensity-Modulated Radiation Therapy for Head-and-Neck Cancer

Osteoradionecrosis (ORN) is a known complication of radiation therapy to the head and neck. However, the incidence of this complication with intensity-modulated radiation therapy (IMRT) and dental sequelae with this technique have not been fully elucidated. From December 2000 to July 2007, 168 patients from our institution have been previously reported for IMRT of the oral cavity, nasopharynx, larynx/hypopharynx, sinus, and oropharynx. All patients underwent pretreatment dental evaluation, including panoramic radiographs, an aggressive fluoride regimen, and a mouthguard when indicated. The median maximum mandibular dose was 6,798 cGy, and the median mean mandibular dose was 3,845 cGy. Patient visits were retrospectively reviewed for the incidence of ORN, and dental records were reviewed for the development of dental events. Univariate analysis was then used to assess the effect of mandibular and parotid gland dosimetric parameters on dental endpoints. With a median clinic follow-up of 37.4 months (range, 0.8-89.6 months), 2 patients, both with oral cavity primaries, experienced ORN. Neither patient had preradiation dental extractions. The maximum mandibular dose and mean mandibular dose of the 2 patients were 7,183 and 6,828 cGy and 5812 and 5335 cGy, respectively. In all, 17% of the patients (n= 29) experienced a dental event. A mean parotid dose of >26 Gy was predictive of a subsequent dental caries, whereas a maximum mandibular dose >70 Gy and a mean mandibular dose >40 Gy were correlated with dental extractions after IMRT. ORN is rare after head-and-neck IMRT, but is more common with oral cavity primaries. Our results suggest different mechanisms for radiation-induced caries versus extractions.

Evaluating the In-vitro Antibacterial Effect of Iranian Propolis on Oral Microorganisms.

Propolis has traditionally been used in curing infections and healing wounds and burns. Current researches have shown that propolis has antibacterial, antifungal and antiviral actions however, the pharmacological activity of propolis is highly variable depending on its geographic origin. There have been few studies on the effects of Iranian propolis on the oral microorganisms. In this in-vitro study, the antimicrobial activity of the ethanolic and water extracts of the Iranian propolis (10%, w/v) from north-east area of Tehran was evaluated. Susceptibility of the oral strains tested (Streptococcus mutans ATCC 35668; Streptococcus salivarius ATCC 9222; Staphylococcus aureus ATCC 25923; Enterococcus faecalis ATCC 9854 and Lactobacillus casei ATCC 39392) was evaluated using the agar diffusion method at a concentration of 20 mg/mL of propolis and the zones of growth inhibition were measured. Antibacterial activity was determined by using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at different concentrations of propolis. The ethanolic extract showed bacteriostatic and bactericidal activity against all the strains, with MIC and MBC ranges of 250-500 µg/mL. The MIC concentration of the water extract was 500 µg/mL against S. mutans and E. faecalis. The water extract showed bactericidal activity only against S. mutans (20 mg/mL). These results indicate that the ethanolic extract is probably more useful in the control of oral biofilms and subsequent dental caries development. However, to determine the consequence of the ethanolic extract of Iranian propolis on the oral mucosa, in-vivo studies of its possible effects are needed.