Journal of Dental Medicine

Background and Aims: Periodontitis is one of the most common oral diseases with the various incidence rates in different populations. A number of bacteria are considered as the major etiologic agents of periodontitis. The aim of the present study was to determine the prevalence of periodontopathogen bacteria in patients using both PCR and culture techniques.
Materials and Methods: In this study, one-hundred patients (including 62 females and 38 males with an average age of 49±11.5 years) with adult periodontitis referred to periodontics department of School of Dentistry/Tehran University of Medical Sciences were investigated. The samples were taken and sent immediately to the laboratory for culture and molecular evaluation. The PCR was performed using specific primers and the statistical analysis of data was performed using SPSS statistic software and McNemar test.
Results: The results demonstrated that the total detection rate in culture method was 64%. The rate of Aggregatibacter actinomycetemcomitans (Aa) was 28% which was significantly higher than that of Porphyromonas gingivalis (Pg) (6%) and Prevotella intermedia (Pi) (3%). 27% of cases showed mixed bacterial growth. 65% of patients were positive using molecular method. The rate of Aa (30%) was significantly higher than that of Pg (7%) and Pi (5%). The mixed PCR positive rate containing of Aa, Pg and Pi was (23%).
Conclusion: In this study, it was found that most of the bacteria isolated using culture and molecular methods were Aa, Pg and Pi, respectively. Although the detection frequencies of both techniques were similar, the specificity, sensitivity and bacterial detection speed of the PCR technique is obviously higher. Therefore, the use of molecular techniques is strongly recommended. However, both techniques seem to be suitable for microbiological diagnostics.

Background and Aims: There is concern that leached components from dental composites may cause adverse changes in the reproductive health. This study aimed to assess the effects of leached components from a hybrid resin composite on the reproductive system of male mice.
Materials and Methods: In the present animal study, twenty adult Syrian male mice were divided into two groups of 10 mice each. In the test group, components which leached from samples made from Filtek Z250 resin composite into 75% ethanol were daily administered to the mice for 28 days. In the control group, the procedure was repeated in the same way as the test group but without placing composite samples in the solution. Then, the body weight, weights of paired testes, Gonado Somatic Index, sperm viability, sperm motility, epididymal sperm reserve and daily sperm production were recorded. Four male mice in each group were mated with untreated female mice for 10 days. After that, the number of pregnant females and number of infants were recorded. The data were analyzed using repeated measures ANOVA, Chi-square test and t-test.
Results: There was a significant reduction in the sperm viability and sperm motility of male mice in the test group compared to the control group (P=0.001). There was no any significant differences in other parameters between two groups (P>0.05).
Conclusion: This study showed that the leached components from resin composites cannot cause infertility but they could potentially cause some adverse effects on the reproductive system of male mice.

Background and Aims: This study was conducted to assess the psychological health status of dentists in Shiraz city.

Materials and Methods: In this cross-sectional study, subjects consisted of 106 dentists and 94 general practitioners (comparison group) from private and public clinics in Shiraz city. Subjects were requested to complete the standard general health questionnaire and a questionnaire on demographic variables. The data were analyzed by appropriate statistical tests. Chi-Square test and independent sample t-test were used to compare demographic and occupational variables of both groups. The questionnaires were scored and the overall score of each individual determined his/her psychological health status. Means of GHQ scores of both groups were compared using statistical tests.

Results: Both groups were similar in all demographic variables, except for age. The mean total score of GHQ-28 for both dentists (17.9) and physicians (16.34) groups were significantly lower than the cut-off point value of 23 (P <0.01). The means of scores for somatic problems, depression, anxiety and insomnia as well as unusual social performance scales were significantly different between both groups (P<0.05). A significant positive association was found between GHQ total score and job tenure.

Conclusion: Our findings revealed that psychological health status of dentists was poorer than that of physicians. Additionally, dentists' scores were significantly different from those of their counterparts in all GHQ sub-scales.

Background and Aims: Nursing Caries (NC) is a destructive form of caries because of incorrect nutritional habits in infants that affects deciduous teeth after eruption. Familiarity with the pattern of this type of caries and evaluation of its symmetrical or asymmetrical pattern is necessary for effective and scientific diagnosis and treatment. The aim was to assess the symmetrical or asymmetrical aspects of Nursing Caries in children between 3-5 years old.

Materials and Methods: In this cross-sectional study, 10 kindergartens were randomly selected by the Tehran Welfare Organization. 115 children with NC caries entered to study after examination. Written consents were obtained from the parents. The dmfs in upper primary incisors and upper and lower primary canines, as well as the first primary molars were assessed and the caries pattern in terms of symmetrical or asymmetrical aspects was evaluated. The data were analyzed by ANOVA, LSD, Chi-square and Fisher tests.

Results: In 53.9% of the children with NC, the anterior teeth were affected symmetrically, while 46.1% indicated an asymmetrical pattern. In general, 32.2% of the teeth were affected in a symmetrical pattern and 67.8% of them in an asymmetrical pattern. About the relationship between the breastfeeding from the right or left breast and the symmetrical pattern of the NC, 51% of the children were equally breastfed from both breasts. However, in the asymmetrical NC pattern with more impact in the right side of dentition, 50% of the children had been breastfed from the left side and in children with more caries  in the left side of dentition, 50% of them had been breastfed from the right side (P=0.01).

Conclusion: NC has symmetrical and asymmetrical patterns. Direction of mother for breastfeeding affects the symmetrical and asymmetrical pattern of NC.

Background and Aims: Re-application of microbrush may affect the micro tensile bond strength of adhesives to dentin. The aim of this study was to evaluate the effect of re-application of microbrushes on the micro tensile bond strength of an adhesive to dentin.

Materials and Methods: Thirty freshly extracted molars teeth were collected and enamel of occlusal surface were removed to expose superficial dentin. Then superficial dentin was etched, washed and partially air dried. According to the times of application of microbrush, teeth were divided into two test groups. In group 1, new microbrushs were used, but in group 2, the ones that were already used for twice were included. Ambar dentin bonding agent (FGM/Brazil) was applied to the etched dentin with microbrushes according to the manufacturer's instructions. Then the crown of teeth was built up with LLiss (FGM/Brazil) composite resin. The teeth were sectioned in buccolingual direction to obtain 1mm slabs. Then 50 hourglass- shape samples were made from 30 teeth (25 Specimens per group). The microtensile bond strength of the specimens was tested using MTD500 (SD Mechatronik, Germany). The data were statistically analyzed by T-test.

Results: The mean values for the microtensile bond strength were 30.49±7.18 and 23.61±9.06 MPa±SD for the first and second groups, respectively. There was significant difference between the groups (P=0.005).

Conclusion: Microbrushes should not be used for more than one cavity preparation.

Background and Aims: One of the decisive factors on the final esthetic results of implant treatment is the abutment material. Ceramic abutments are nowadays very popular in this regard. The purpose of this study was to compare the fracture resistance of three zirconia abutments with titanium abutment.

Materials and Methods: Four groups of abutments (five specimens in each) were prepared. The abutments were prefabricated titanium, prefabricated zirconia, zirconia-metal, and copy-milled zirconia abutment. After securing the abutments to the implant using a torque of 24 Ncm, they were mounted into a mounting jig using the 30º tilt. The force was applied on the assembly till the failure occured. Facture resistance and mode of failure were recorded for each specimen. The data were analyzed using One-way ANOVA.

Results: The mean values recorded for fracture resistance of different zirconia abutments varied between 426 to 688 N however, there was no significant differences among the groups (P=0.14). Body fracture was observed only in prefabricated zirconia abutments. Screw fracture and screw bending were the common failures observed in other groups.

Conclusion: Zirconia abutments of any type could be successfully used in regular plateform implants.

Background and Aims: Different mechanisms have been developed for connecting abutment to implant. One of the most popular mechanisms is Tapered Integrated Screw (TIS), which is a Tapered Interference Fit (TIF) with a screw integrated at the bottom of that. The aim of this study was to investigate the mechanism of TIS and effective factors in employing TIS during design and implementation processes using an analytic method.

Materials and Methods: Relevant equations were developed to predict tightening and loosening torques, contact pressure and preloads with and without bone tissue in this analysis. The efficiency is defined as the ratio of the loosening torque to the tightening torque. The effects of the change in elastic modulus and thickness of the bone on operation of this mechanism were investigated.

Results: In this study, 14 independent parameters such as taper angle, friction coefficient, abutment and implant geometry that are effective on performance of TIS mechanism were presented. The role of some factors was shown in the performance of ITI implant using sensitivity analysis.

Conclusion: It was shown that friction coefficient, contact length, and implant radius play major roles on tightening and loosening torques and efficiency of the mechanism. Furthermore, the results revealed that the change in the elastic modulus and thickness of the bone influenced the efficiency of the mechanism less than 15%.

Background and Aims: The purpose of this study was to evaluate the sealing ability of different thicknesses of orthograde MTA plugs in comparison with 5 mm gutta-percha.

Materials and Methods: Fifty extracted single rooted human teeth were collected. After root canal preparation, the samples were randomly divided into 4 experimental (n=10) and two control groups (n=5). In group 1, the apical 5 mm of the canals were obturated using laterally condensed gutta-percha and sealer AH26. Groups 2, 3 and 4 received 2, 3 and 4-mm thick orthograde MTA plug, respectively. Thereafter, the coronal portion of specimens was exposed to the microbial solution containing streptococcus sanguis and the root tips were placed in phenol red lactose broth. The color changes were observed within 60 days. The data were analyzed with Fisher exact test.

Results: The leakage was found in all samples (100%) in group 1 and 72.7%, 30.8% and 50% of the samples in groups 2, 3 and 4, respectively. Significant difference was found between 3 mm thickness of MTA plug and gutta percha and sealer (P=0.02).

Conclusion: According to the findings, it seems that 3 mm thickness of orthograde MTA plug had better sealing ability than the other thicknesses of MTA plug as well as the 5 mm of gutta-percha.

Background and Aims: Today, use of adhesive systems is the most common materials in restorative dental procedures. The aim of this study was to evaluate the effect of different air-drying periods on the microtensile bond strength of composite to dentin using adhesive.

Materials and Methods: 15 sound molar teeth were selected. The an occlusal surfaces of teeth were removed with silicon carbide disks (3M/USA) to reach flat surface of dentin. Then according to the air drying of solvent, the teeth were divided to five groups. After 5 sec etching and rinsing for 15 sec , the teeth were air dried for 3 sec . Then Singlebond (3M) was used with different air-drying times (0s, 2s, 5s, 10s, 30s) and cured. Then after insertion and curing of Saremco (microhybrid low shrinkage/Switzerland) composite, the teeth were thermocycled for 500 cycles. Then hour glass slabs with 1 mm² interface was created. Specimens were then subjected to µTBS force until fracture. Data were analyzed using ANOVA and Bonferroni tests.

Results: Statistical tests showed that there were significant differences between bond strength of groups (P=0.002). The mean of µTBS for the 2 Sec and 30 Sec evaporating time was the most and the least vawes, respectively.

Conclusion: An optimum air-drying time for solvent evaporation was the lowest time recommended by the manufacturer. Over and under evaporation time decreased µTBS significantly.

  Background and Aims: The purpose of this study was to evaluate the tissue responses to octacalcium phosphate (OCP) and calcium hydroxide (CH) used as direct pulp capping (DPC) materials in cat teeth.

  Materials and Methods: 72 premolar teeth of 9 cats were selected and divided into 3 groups (Two experimental and one control group). After the cats had been anesthetized, the pulp were exposed and capped directly with OCP, CH or no capping material as control group. The cavities of all three groups were filled with Glass ionomer cement (GI). Histological evaluations were performed at two, four and eight weeks after pulp capping. After tissue preparation procedures, paraffin blocks were prepared. After preparation and staining of the sections, the relevant variables were measured by optical microscope. The results were analyzed using Mann-Whitney U and Chi-square tests ( α =0.05).

  Results: Two weeks after pulp capping, all specimens in three groups showed mild to sever inflammation. The formation of hard tissue (dentinal bridge) at in the exposed areas of the experimental groups was more noticeable for calcium hydroxide than that of octacalcium phosphate group. These differences were statistically significant (P<0.001). At four weeks, hard tissues were observed in both groups which were more evident for the CH group and there were statistically significant difference between two experimental groups (p<0.003). At eight weeks, continuous hard tissues were observed in both groups and there were no statistically significant difference between them (P>0.05), but hard tissues continuity were better for in the OCP than that of the CH.

  Conclusion: It seems that the formation of hard tissue in CH because of its porosities had a worse percentage in sealing of the pulp than the OCP .

  Background and Aims: Different adhesives with different solvents may have different solvent evaporation rates. The purpose of this study was to evaluate the solvent evaporation in the self etch and total etch adhesive in different air drying times.

  Materials and Methods: Five adhesives were used in this study: Excite, Prime & Bond NT, UNO, Single Bond, SE Bond Primer. Twelve drops of each adhesive were used for each period of air drying (5, 15, 30 sec). The percentage of mass loss was measured during each test. Data were analized using two-way ANOVA and Tukey.

  Results: Acetone base adhesives showed more loss of mass than other adhesives (P<0.01). P&B NT showed more loss of mass than other adhesives in all air drying times (P<0.01). Adhesives showed different evaporation rates in different air times (P<0.01).

  Conclusion: Adhesives with acetone/water or alcohol/water solvent shows more stable behavior in comparison with adhesives containing pure aqueous solvents.

  Background and Aims: Bleaching agents not only affect the tooth structure, but also may alter the properties of restorative materials. The aim of this in vitro study was to evaluate the effect of different bleaching regimens on the microhardness of four tooth-colored restorative materials.

  Materials and Methods: Eighty specimens of four restorative materials (Microhybrid resin composite (Z250 (3M, ESPE), nanohybrid composite Z350 (3M, ESPE), packable composite P60 (3M, ESPE), and resin modified glass ionomer Vitremer (3M, ESPE)) were fabricated and were polished after 24 h with Soflex discs (3M,ESPE). Then the specimens were divided into two groups: In office bleach group, 40 specimens (10 of each restorative material) were bleached with hydrogen peroxide 37.5% for 30 min in two sessions with 7 days interval. In home bleaching group, 40 specimens were bleached with carbamid peroxide 22%, 6 h a day for 14 days. Vickers microhardness test were done before and after bleaching (baseline). Finally data were evaluated using analysis of Variance.

  Results: Two bleaching regimens were significantly decreased the microhardness values. In Z250 resin composite, the microhardness values before and after bleaching were 95.30 and 92.67 kg/mm², respectively. for office bleaching (P=0.011) and 95.38 and 92.39 kg/mm² for home bleaching (P<0.001). In Z350 resin composite, the microhardness values before and after bleaching were 98.29 and 92.41 kg/mm², for office bleaching (P<0.001) and 97.35 and 93.44 kg/mm² for home bleaching (P<0.001) respectively. In P60 resin composite, the microhardness values before and after bleaching were 103.10 and 96.16 kg/mm², respectively. for office bleaching (P=0.045) and 102.61 and 98.16 kg/mm² for home bleaching (P=0.001). In resin modified glass ionomer (Vitremer), the microhardness values before and after bleaching were 56.79 and 49.41 kg/mm², respectively. for office bleaching (P=0.004) and 54.17 and 46.50 kg/mm² for home bleaching (P<0.001). There was no significant difference between two bleaching agents (P=0.365).

  Conclusion: Dental bleaching agents decrease the microhardness of tooth-colored restorative materials.

  Background and Aims: Iatrogenic damage to adjacent tooth during proximal cavity preparation is one of the most common side effects in operative dentistry. The aim of this study was to determine prevalence of iatrogenic damages to adjacent tooth during the preparation of proximal Class II cavities among undergraduate students at dental faculty of Tehran University of Medical Sciences in 2010 .

  Materials and Methods: 106 posterior permanent teeth which had Class II decay with sound proximal surfaces of adjacent teeth were selected and restored by dental students awarding the aims of the present study. After finishing restoration, proximal surfaces were completely dried by air and evaluated with dental chair light. In doubtful cases, surfaces were evaluated with × 3 magnification. Damages were classified into 2 groups abrasion and groove. Data were analyzed using Fishers exact and Pearson chi square tests .

  Results: The frequency of adjacent surfaces damage were 57.5%, with 31.1% damages as abrasion and 26.4% as groove. Students who used matrix band and wedge in proximal area as preventive instruments showed 53.4% damages and other students showed 57.3% damages (P>0.05). A significantly higher number of females and students at restorative course level (3) used wedge and matrix band than males and students at restorative course level (4) for protecting adjacent teeth (P<0.05).

  Conclusion: According to the high percentage of iatrogenic damages on adjacent sound teeth in class II cavity preparation, teaching of preventive methods and using proper techniques is necessary for dental students as future dentists.

  Background and Aims: One of the important aspects for evaluating an organization is assessing the level of satisfaction of the clients. This study was conducted to compare the level of satisfaction between traditional and new methods of delivering dental care in the clinic of Tehran University of Medical Sciences.

  Materials and Methods: A cross-sectional study was conducted on 308 patients received dental care at the dental clinics of Tehran University of Medical Sciences in spring 2010. Data were collected from Comprehensive Care Unit (CCU) in addition to 7 isolated clinics including restorative, periodontics, endodontics, radiology, and prosthodontics (fix and removable) using translated version of the Dental Satisfaction Questionnaire (DSQ), consisted of 19 questions in three main domains in addition to demographic questions. Descriptive statistics was used as percentage of answers. In order to compare the mean score between domains ANOVA test was used.

  Results: The standardized mean scores in each domain were: pain control 58±17, access 59±12, quality 68±11 and total Dental Satisfaction Index (DSI) score of 62±10. 92.5% of the respondents reported that students were very careful when examining their patients. 96.8% reported that they treat their patients with respect . The most common reasons for dissatisfaction apart from waiting time and getting appointments were not providing preventive care and pain control.

  Conclusion: The results of this study shows acceptable level of satisfaction with dental care in teaching clinics of this dental school, however efforts on implementing preventive care and pain control strategies are suggested.

  Background and Aims: Retention and stability of the post and core system is the key factor for success of final restoration . The aim of this study was to evaluate the microtensile bond strength of the different composite core materials and bonding systems to a fiber post.

  Materials and Methods: To evaluate the bond strength of the composite resins to a fiber post ( DT light post) 60 posts were divided into six groups : group A: Heliomolar Flow + Seal Bond, group B: Heliomolar Flow + SE Bond , group C: Valux Plus + Seal Bond , group D: Valux Plus + SE Bond , group E: Corecem + Seal Bond, group F: Corecem + SE Bond. All samples were thermocycled for 5000 cycles (5-55 ⁰C) and cut into four bars for the microtensile bond strength test. Failure modes were identified using a stereomicroscope. Data were analysed using One-way ANOVA and Tukey HSD post hoc test (P<0.05).

  Results: The interaction between composite resin materials and bonding systems were positive. The conventional hybrid composite (Valux Plus) had significantly higher bond strength compared with the core specific flowable composite (Corecem) when Seal Bond was applied as bonding agent (P<0.05). However, when SE Bond was utilized hybrid composite demonstrated significantly lower bond strength than that of other two groups (P<0.05).

  Conclusion: The performance of a particular composite is affected by the bonding system that is applied. A single composite resin may have different bond strength when combined with different bonding system.

  Background and Aims: Dental implants have been studied for replacement of missing teeth for many years. Productivity of implants is extremely related to the stability and resistance under applied loads and the minimum stress in jaw bone. The purpose of this study was to study numerically the 3D model of implant under thermal loads.

  Materials and Methods: Bone and the ITI implant were modeled in “Solidworks” software. To obtain the exact model, the bone was assumed as a linear orthotropic material. The implant system, including implant, abutment, framework and crown were modeled and located in the bone. After importing the model in Abaqus software, the material properties and boundary conditions and loads were applied and after meshing, the model was analyzed. In this analysis, the loads were applied in two steps. In the first step, the mechanical load was applied as tightening torque to the abutment and the abutment was tightened in the implant with 35 N.cm torque. In the second step, the thermal load originated from drinking cold and hot water was applied as thermal flux on the ceramic crown surface in this model.

  Results: Thermal analysis results showed that the thermal gradient in the bone was about 5.5 and 4.9 degrees of centigrade in the case of drinking cold and hot water respectively , although the maximum gradient of the whole system was reduced to 14 degrees, which occurred, in the crown by drinking cold water.

  Conclusion Thermal stresses were so small and it was because of the low thermal gradient. Maximum stresses occurred in the abutment were due to the tension preloads which were originated from the tightening torque.

  Background and Aims: Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to root resorption of the adjacent tooth. The purpose of this study was to determine this resorption using panoramic and periapical radiographs.

  Materials and Methods: In this cross-sectional descriptive study 54 patient (28 men, 26 women) above 15 years old with the average of 22 years in Oral and Maxillofacial Department of Tehran University were studied. A periapical radiography from the third molar and a panoramic radiograph were taken from each patient (Because of their routine use and evaluation of accuracy of panoramic compared with periapical), and the magnitude of the root resorption for the second molar was determined by 2 observers and written in a questionnaire. Data were analyzed using Fisher test.

  Results: The prevalence of the root resorption of the second molar adjacent to the impacted third molar in the panoramic and the periapical radiographies, with respect to the limitation of the sample size were 46.3% and 31.5%, respectively, with 95% confidence(P>0.05). Most of these resorptions were in the cervical third of the second molar roots and in cases in which the third molars were mesially oriented or horizontal. There was also no significant difference between panoramic and periapical radiographs.

  Conclusion: Due to the increased risk of the resorption of the second molar adjacent to the third molar, extraction of the impacted third molars, especiall y mesially oriented or horizontal ones are recommended.

  Background and Aims: Application of fluoride products is known as one of the most successful interventions to prevent dental caries. This study aimed to compare the costs of in-office fluoride therapy versus salt fluoridation in Iranian population.

  Materials and Methods: In this study, the costs relating to the use of in-office fluoride therapy were analyzed using Activity Based Costing during 2011 from two perspectives. From the perspective of service provider, direct medical costs and indirect costs and from the view of service recipient, three parts: direct medical and non-medical costs and indirect costs, were considered. Costing for public consumption of salt fluoridation was estimated based on salt processing costs, including purchase, installation, monitoring, maintenance and repair of machinery, equipment, personnel expenses and cost of raw materials, used in this study.

  Results: Costs relating to performing a single in-office fluoride therapy was estimated to be 245,032 Rials from the perspective of service providers, and 239,600 Rials from the patient view. Estimated total cost to produce fluoridated salt for a unit of 10 million populations, was calculated to be 35 billion and 940 million Rials or 3, 594 Rials per person per year.

  Conclusion: It was concluded that per-capita costs of community based salt fluoridation was far less than in-office fluoride therapy. Salt fluoridation could be advised to be an affordable way to prevent dental caries in Iranian population.

  Background and Aims : As midwives are in frequent contact with pregnant mothers, they may play a key role in their oral health care (OHC). In this study, we aimed to evaluate the effect of an educational program on Tehran University of Medical Sciences midwifery students’ knowledge and preparedness on OHC in pregnant mothers. Materials and Methods: The midwifery third year students of central campus (n=29) were randomly selected as intervention group and their counterparts in Hemmat campus (n=33) as control. Students in both groups were asked to fill in a questionnaire included 8 demographic question and 18 OHC knowledge and one question on their preparedness to implement OHC. Then the educational intervention was implemented using lecture, demonstration of the correct methods of brushing and flossing on the models and role play method. The follow- up questionnaire was delivered 3 months later. Data were analyzed using Mann-Whitney test, T-test, Chi-Square test, ANOVA and Regression by SPSS software.

  Results: The mean OHC in pregnancy knowledge score in intervention and control group were 26.7 and 24.8 at baseline which were changed into 48.5 and 29.1, respectively (P<0.001). Among the students 52.6% in the intervention group and 36.4% in the control group reported very high preparedness to implement OHC in pregnancy. These figures were 68.2% and 41.7% in the post-test.

  Conclusion: The promising findings of this educational intervention comprising of both student and teacher-centered methods speak for possibility of improving these students knowledge and preparedness and implies on the necessity to incorporate the related course in midwifery education.

  Background and Aims: Since recurrent caries are one of the major causes of failure in resin restorations, the production of antibacterial resin composites was always under investigation. The aim of this study was to evaluate the efficacy of fissure sealants containing nanosilver particles against the Streptococcus mutans.

  Materials and Methods: In this experimental study, the antibacterial properties of two sealants (with fluoride (Clinpro 3M) and without fluoride (Concise 3M) was investigated with 0, 0.01, 0.02, 0.03, 0.04, 0.05% w/w after adding nano-silver using direct contact test. Sealants formed on the walls of 500ml micro tube and after curing, they left in contact with bacterial suspension. In periods of 3, 24, 48h, a 10 µl volume of liquid medium was placed in blood agar culture and after 24 h incubation at 37ºC, the number of S.mutans colony was counted by colony counter. Data were analyzed using ANOVA and
T-test.

  Results: Results reported sealants with fluoride comparing to non fluoride ones had significant effect on inhibition of S.mutans growth (P<0.001). The direct contact test demonstrated that by increasing the amount of nano particles, the bacterial growth was significantly diminished (P<0.001).

  Conclusion: While sealants with fluoride demonstrated antibacterial effect, sealants with incorporation of higher weight percentage of nanosilver particles, had stronger and more significant antibacterial effect in direct contact test.