Calcium Hydroxide Cement Research Articles

Evaluation of Microstrain in the Regions Surrounding Morse Taper and External Hexagon Implants.

The aim of this study was to compare the Morse taper (MT) + titanium base (Ti-Base) abutment with the external hexagon (EH) + Ti-Base abutment by using the strain gauge method in the mesial, distal, and apical-buccal areas around these types of implants. This study investigated two groups, MT and EH, each comprising five polyurethane samples with a dental implant (3.75 × 11.5 mm) in the area of artificial tooth 15. The strain gauges were glued to the mesial, distal, and apical-buccal polyurethane areas of all samples in relation to the implant. Ti-Base nonangled abutments were installed on the implants in each group. Ten identical zirconia crowns were constructed by scanning and milling and were subsequently cemented onto the Ti-base abutments with calcium hydroxide cement. Then, an axial load of 100 N was applied to the occlusal region of the zirconia crowns, and strain gauge measurements were taken. Strain gauge data were assessed by a two-way analysis of variance (ANOVA) with "implant connection" and "strain gauge position" factors, followed by the Bonferroni test (p < 0.05). The MT group showed significantly lower microstrain values in the mesial and apical strain gauges compared to the EH group. The MT group exhibited less microstrain in the mesial and apical areas of the polyurethane samples near the implant. Consequently, the MT connection was considered more biomechanically advantageous.

Solubilidade e pH dos cimentos forradores de hidróxido de cálcio

ABSTRACT Objective: To analyze the solubility and the potential of hydrogen ions in calcium hydroxide-based lining cements used in dentistry to protect the dentin-pulp complex during rehabilitation treatments. Methods: The evaluated cements bear the commercial names Dycal (Dentsply Sirona), Hydcal (Maquira), Hydro C (Dentsply Sirona), and light-cured Biocal (Biodinâmica). Solubility measurements followed the methodologies proposed by the American National Standards Institute and the American Dental Association, while the potential of hydrogen was determined using a digital pH meter. Results: Solubility exhibited no significant differences either individually or between the groups. Regarding the potential of hydrogen, the results were as follows: Dycal 12.06, Hydcal 12.06, Hydro C 10.5, and light-cured Biocal 8.48, highlighting disparities between the groups. Conclusion: There were no statistically significant differences in the descriptive analysis of the solubility of the tested calcium hydroxide cements. However, the descriptive analysis of the pH of the cements revealed statistically significant variances between the groups.

Calcium Ions Released from Light - Cured Calcium Hydroxide Cement using Argon - Based Induction Coupled Mass Spectroscopy

Calcium Ions Released from Light - Cured Calcium Hydroxide Cement using Argon - Based Induction Coupled Mass Spectroscopy

Selective Removal to Soft Dentine versus Full Pulpotomy for Management of Proximal Deep Carious Lesions: A Randomized Controlled Non-Inferiority Trial

The management of the deep carious lesion with reversible pulpitis is a dilemma for the dentist. The current study compared selective removal to soft dentine (SRSD) and full pulpotomy (FP) for treating proximal deep carious lesions in teeth with reversible pulpitis. Visual-tactile examination and bitewing radiographs were used to determine the depth of carious lesion, and American Association of Endodontists recommendations were used to formulate pulp diagnosis. Sixty mandibular molar teeth from healthy patients between the ages of 16–35 years and a diagnosis of proximal deep carious lesion with reversible pulpitis were included. Teeth were randomly allocated to two study groups. SRSD group (n = 30): soft dentine was preserved over the pulpal aspect. A hard-setting calcium hydroxide cement liner and resin-modified glass ionomer cement base were applied over the remaining soft carious dentine. FP group (n = 30): complete caries removal followed by mineral trioxide aggregate FP was performed. The teeth in both groups were restored with composite resin restoration. The established criteria for outcome assessment of SRSD and pulpotomy were used. Accordingly, only asymptomatic teeth with no radiological evidence of periapical rarefaction were considered successful at the 12-month follow-up. Two-sample t test, Pearson χ² test/Fisher’s exact test, and percentage agreement were used for statistical evaluation. According to the per-protocol analysis, the success rate of both SRSD and FP treatment was 95.45% and 95.65%, respectively, and the actual difference between the two treatments was 1% (95% CI: [−10, 9]). The data suggests that both treatments (SRSD and FP) appear to have a good success rate (>95%) when used to manage permanent mandibular molar teeth with proximal deep carious lesion and reversible pulpitis. As SRSD is a noninvasive procedure, it should be favored over FP in these instances.

PH, Ion Release Capability, and Solubility Value of Premixed Mineral Trioxide Aggregates

The current study aimed to compare the pH, solubility value, and ion release capability of premixed mineral trioxide aggregates (MTAs) versus conventional pulp capping materials before and after setting. The following materials were used: resin-modified calcium silicate cement (TheraCal LC&lt;sup&gt;®&lt;/sup&gt;, TLC), resin-modified calcium hydroxide cement (Ultra-Blend&lt;sup&gt;TM&lt;/sup&gt; plus, UBP), and 2 kinds of premixed MTA (Endocem MTA&lt;sup&gt;®&lt;/sup&gt; premixed regular 〔EMPR〕 and Well-Root&lt;sup&gt;TM&lt;/sup&gt; PT 〔WRP〕). The specimens of each material were prepared before and after setting and were immersed in distilled water. The materials’ pH and solubility value were assessed. Next, three kinds of ion (calcium, sulfide, and strontium) released by pulp capping materials were evaluated via inductively coupled plasma atomic emission spectrometry. In the after-setting group, the pH of TLC and UBP decreased. However, the pH of the premixed MTAs increased with time. TLC released a higher concentration of strontium ion compared with the other materials. Meanwhile, EMPR released a significantly high concentration of sulfide ion (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). In the after-setting group, the 2 kinds of premixed MTAs released a significantly higher concentration of calcium ion compared with the other materials (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). In the after-setting group, EMPR had a significantly low solubility value (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). The Kruskal-Wallis test, followed by the Mann-Whitney U test with Bonferroni correction, was used in statistical analysis. In conclusion, resin-modified calcium silicate cement, modified calcium hydroxide cement, and the 2 kinds of premixed MTAs had an alkaline pH and low solubility value and they released various concentrations of ions after setting.

Development and physical-mechanical characterization of experimental self-adhesive calcium-based cements for pulp capping

This study aimed to evaluate the bond strength (BS), degree of conversion (DC), calcium release (CR), and viscosity (VS) of experimental self-adhesive calcium-based cements for pulp capping purposes. Three resin-based experimental cements containing no calcium (CONTROL), calcium hydroxide (HYDROCAL), and calcium chloride (CLORECAL) were synthesized and compared with a commercial resin-based calcium hydroxide cement (Ultra-Blend Plus® - ULTRAPLUS). For the BS, a testing machine performed in bovine dentin (n = 10). The DC (n = 5) was measured through Fourier Transform Infrared Spectroscopy coupled to an attenuated total reflectance device (FTIR/ATR). The CR (n = 5) was analyzed through an atomic absorption spectrophotometer at 3 h, 24 h and 72 h. A rheometer was used to obtain the VS (n = 5). The data were statistically analyzed using one and two-way ANOVA/Tukey tests (α = 0.05). For BS, all experimental materials showed statistically higher values than the commercial material (p < 0.01). For the DC, the CONTROL and HYDROCAL cements showed statistically higher values than the others (p < 0.01). CLORECAL and ULTRAPLUS showed statistically higher CR values after 72 h (p < 0.01). The HYDROCAL and CLORECAL cements showed statistically higher VS values than the others (p < 0.01). Therefore, the experimental calcium chloride-based cement presented a better overall behavior.

Invasive Cervical Resorption of a Mandibular Molar Managed with Vital Pulp Therapy: Exemplar Case Study

This exemplar case highlights the importance of conservative treatment to protect the pulpal health of an invasive cervical resorption of a mandibular molar tooth with pulpal exposure. The resorptive site was explored and trichloroacetic acid (TCA) was placed on the localized defect. Following curettage of the resorptive tissue, a small pulp exposure occurred. Direct pulp capping with Dycal, a calcium hydroxide-based material, was used, and the molar was restored with glass ionomer cement. At the 18-month review, the molar tooth demonstrated both clinical (positive pulpal response) and radiographic (absence of any periapical radiolucency) success. Clinical relevance Direct pulp capping with calcium hydroxide cement is an inexpensive, conservative, and easy treatment option for pulpal exposure during the management of a Class 2 invasive cervical resorption case. Objective To demonstrate the importance of preserving the pulp in the management of a Class 2 invasive cervical resorption lesion.

Children’s self-reported discomfort of restorative treatments for deep caries lesions in primary teeth: Results from a randomized clinical trial

The aim of this study was to evaluate the impact of different restorative techniques to treat deep caries lesions of primary molars on children’s self-reported discomfort. A randomized clinical trial with two parallel arms (1:1) was conducted in São Paulo, Brazil. 4-8 years-old children with at least one occlusal or occlusoproximal deep caries lesion in primary molars were selected. Molars were randomly allocated into two groups: (1) restoration performed with calcium hydroxide cement followed by high-viscosity Glass Ionomer Cement (CHC+HVGIC), and (2) HVGIC restoration. Immediately after the intervention, children reported the experienced discomfort during restoration to an external examiner using a Wong-Baker face-scale. Children’s self-reported discomfort was analyzed using Poisson regression comparing both groups and assessing other variables’ influence (α=5%). One hundred and eight children fulfilled the eligibility criteria and were randomized in the two groups (n=54). Most of the children who received CHC+HVGIC restorations reported none or minimal discomfort (83.3%). Similar scores (92.6%) were reported for those treated with HVGIC (p=0.758). The mean reported discomfort in children with CHC+HVGIC restorations was 0.37(1.01), and 0.41(1.01) for those with HVGIC restorations. Children’s self-reported discomfort was associated with age, sex, children’s cooperation, and intervention duration. We can conclude that CHC+HVGIC or HVGIC restorations result in none or minimal discomfort in the management of deep caries lesions, being considered a reliable option.

The effect of mineral trioxide aggregate on dental pulp healing in the infected pulp by direct pulp capping.

This study aimed to clarify the effect of mineral trioxide aggregate (MTA) on pulp healing in the infected pulp by direct pulp capping (DPC). Thirty-six male ICR mice were divided into infected and uninfected groups. The pulp tissue was exposed to the oral flora for 24 h after pulp exposure in the infected group, or not exposed in the uninfected group, followed by sealing with MTA, calcium hydroxide cement (CH), or no DPC. Pulpal healing process was analyzed by hematoxylin-eosin staining and immunohistochemistry for nestin and Ki67. The active cell proliferation occurred on 1 week in the both MTA and CH groups, followed by the differentiation of odontoblast-like cells on 2 weeks in the MTA group, whereas their differentiation were not facilitated in the CH group. MTA is suggested to be a useful material for DPC with the infected and uninfected pulp tissue.

Cellular response of human apical papilla cells to calcium hydroxide and tricalcium silicate-based cements

BackgroundThis study aimed to evaluate the biological response of human apical papilla cells to different calcium hydroxide formulations and three tricalcium silicate-based materials.MethodsPrimary cells were obtained from explants of young immature premolars. 20,000 cells adhered for 24 h over discs of Biodentine™, ProRoot®MTA, BioRoot®RCS and calcium hydroxide mixed either with sodium chloride 0.9%w/v or polyethylene glycol and UltraCal® were used to evaluate cell adhesion by scanning electron microscopy and cell viability by MTT assay.ResultsCells adhered to ProRoot®MTA showed an increase of F-actin like protrusions, suggesting bioactivity. Cells adhered to UltraCal® show protrusion such as filopodia. On the contrary, cells adhered to BioRoot®RCS showed no signs of any cellular protrusion. Regarding viability between the materials, we found a higher percentage of viability in cells cultured over discs of Biodentine™ and ProRoot®MTA.ConclusionProRoot®MTA and Biodentine™ exhibit a better cellular response of human apical papilla cells in vitro conditions compared to BioRoot® and calcium hydroxide diluted in sodium chloride.

Pulp liner materials in selective caries removal: study protocol for a randomised controlled trial

IntroductionThe literature shows that selective carious tissue removal (SCTR) decreases the number and diversity of bacteria, stops the caries process and reduces the risk of pulp exposure. However, no consensus...

A Bacteriological study on mineral trioxide aggregate and calcium hydroxide as materials against Streptococcus mutans

Background: Streptococcus mutans play an important role in occurrence of dental caries objective: to compare the clinical and microbiological antibacterial outcomes of Mineral trioxide aggregate (MTA) and Calcium hydroxide cement Ca(OH)2. Methodology: 20 primary molars in 10 children with year’s 5-9 y .For each child one tooth was treated with Ca(OH)2 and the other with MTA. Finally, all the cavities were restored using compomer restorative material, and then microbiological parameters were recorded. Results: MTA treated teeth did not show any clinical sign or symptoms of failure. While three teeth treated with Ca(OH)2 were excluded because of necrosis. Changes in color and consistency of dentin were nearly the same for both groups. Microbiological evaluation showed a decrease in the count of Str. mutans with calcium hydroxide and complete killing of bacteria with MTA. Conclusion: The treatment showed satisfactory results of MTA as it was more potent inhibitor of bacterial-growth than Ca(OH)2

Responses of oral-microflora-exposed dental pulp to capping with a triple antibiotic paste or calcium hydroxide cement in mouse molars.

IntroductionResponses of oral-microflora-exposed dental pulp to a triple antibiotic paste (TAP), a mixture of ciprofloxacin, metronidazole, and minocycline in ointment with macrogol and propylene glycol, remain to be fully clarified at the cellular level. This study aimed to elucidate responses of oral-microflora-exposed dental pulp to capping with TAP in mouse molars.MethodsA cavity was prepared on the first molars of 6-week-old mice to expose the dental pulp for 24 h. The exposed pulp was capped with TAP (TAP group) or calcium hydroxide cement (CH group), in addition to the combination of macrogol (M) and propylene glycol (P) (MP, control group), followed by a glass ionomer cement filling. The samples were collected at intervals of 1, 2, and 3 weeks, and immunohistochemistry for nestin and Ki-67 and deoxyuride-5′-triphosphate biotin nick end labeling (TUNEL) assay were performed in addition to quantitative real-time polymerase chain reaction (qRT-PCR) analyses.ResultsThe highest occurrence rate of pulp necrosis was found in the control group followed by the CH group at Weeks 2 and 3, whereas the highest occurrence rate of healed areas in the dental pulp was observed in the TAP group at each time point. Tertiary dentin formation was first observed in the dental pulp of the TAP group at Week 2. In contrast, bone-like and/or fibrous tissues were frequently observed in the CH group. qRT-PCR analyses clarified that TAP activated the stem and dendritic cells at Weeks 1 and 2, respectively.ConclusionsThe use of TAP as a pulp-capping agent improved the healing process of oral-microflora-exposed dental pulp in mouse molars.

The influence of carboxylated styrene butadiene rubber coating on the mechanical performance of vegetable fibers and on their interface with a cement matrix

Carboxylated styrene butadiene rubber (XSBR) coating was applied on several vegetable fibers and its effect on physical–chemical and mechanical performance were evaluated. Curauá, jute and sisal fibers were used in this study. The influence of coating treatment was evaluated by water absorption capacity test, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetry (TGA). Pullout tests were performed in order to evaluate the fiber–matrix bonding. Fiber embedment lengths of 25 mm was used. A free calcium hydroxide cement mortar was used as matrix. Furthermore, direct tensile tests were performed in the treated and virgin natural fibers. The treatment creates a polymer layer surrounding the fiber, reducing the water absorption capability. The results indicate an increase of the tensile strength of all studied fibers. The interaction between the polymer and natural fibers may be ruled by the cellulose amount of fibers and their crystallinity. An increase in maximum load was observed during fiber pullout, as a consequence of the increase of chemical bonding between treated fibers and the cementitious matrix.

Influence of exposure to phosphoric and polyacrylic acids on selected microscopic and physical/chemical properties of calcium hydroxide cements

This study aimed to evaluate if the contact of calcium hydroxide cements with polyacrylic and phosphoric acids would alter selected microscopic and physical and chemical properties. Chemically activated (Hydro C and Dycal Advanced Formula II) and resin-modified photoactivated (Ultra-blend Plus) calcium hydroxide cements were examined after exposure to the following different strategies: contact with no substance (control group); rinsing with water and drying; contact with polyacrylic acid, rinsing with water, and drying; and contact with phosphoric acid, rinsing with water, and drying. Surface morphology, determined by scanning electron microscopy (SEM), water sorption and solubility, and the release of hydroxyl ions were evaluated. SEM showed a greater impact of the conditioning acids on the surface of the chemically activated cements. Ultra-blend Plus obtained the highest value of sorption (516.8 μg/mm3) and solubility (381.1 μg/mm3) and Hydro C had the lowest values 251.9 μg/mm3 and 206.3 μg/mm3 respectively. Considering the release of hydroxyl ions in comparison with time, Hydro C and Ultra-blend Plus presented significant statistical difference for polyacrylic and phosphoric acid subgroups. Hydro C and Dycal presented intensification of surface irregularities after contact with conditioning acids. The chemically activated materials suffered a decrease in sorption and solubility. The action of the conditioning acids promotes greater increase of the release of hydroxyl ions for Hydro C and Dycal.

Cytotoxicity and Bioactivity of Dental Pulp-Capping Agents towards Human Tooth-Pulp Cells: A Systematic Review of In-Vitro Studies and Meta-Analysis of Randomized and Controlled Clinical Trials.

Background. In the era of biology-driven endodontics, vital pulp therapies are regaining popularity as a valid clinical option to postpone root-canal treatment. In this sense, many different materials are available in the market for pulp-capping purposes. Objectives. The main aim of this systematic review and meta-analysis was to examine literature regarding cytotoxicity and bioactivity of pulp-capping agents by exposure of human dental pulp cells of primary origin to these materials. A secondary objective was to evaluate the inflammatory reaction and reparative dentin-bridge formation induced by the different pulp-capping agents on human pulp tissue. Data sources. A literature search strategy was carried out on PubMed, EMBASE and the Web of Science databases. The last search was done on 1 May 2020. No filters or language restrictions were initially applied. Two researchers independently selected the studies and extracted the data. Study selection included eligibility criteria, participants and interventions, study appraisal and synthesis methods. In vitro studies were included when human dental pulp cells of primary origin were (in) directly exposed to pulp-capping agents. Parallel or split-mouth randomized or controlled clinical trials (RCT or CCT) were selected to investigate the effects of different pulp-capping agents on the inflammation and reparative bridge-formation capacity of human pulp tissue. Data were synthesized via odds ratios (95% confidence interval) with fixed or random effects models, depending on the homogeneity of the studies. The relative risks (95% confidence interval) were presented for the sake of interpretation. Results. In total, 26 in vitro and 30 in vivo studies were included in the systematic review and meta-analysis, respectively. The qualitative analysis of in vitro data suggested that resin-free hydraulic calcium-silicate cements promote cell viability and bioactivity towards human dental pulp cells better than resin-based calcium-silicate cements, glass ionomers and calcium-hydroxide cements. The meta-analysis of the in vivo studies indicated that calcium-hydroxide powder/saline promotes reparative bridge formation better than the popular commercial resin-free calcium-silicate cement Pro-Root MTA (Dentsply-Sirona), although the difference was borderline non-significant (p = 0.06), and better than calcium-hydroxide cements (p < 0.0001). Moreover, resin-free pulp-capping agents fostered the formation of a complete reparative bridge better than resin-based materials (p < 0.001). On the other hand, no difference was found among the different materials tested regarding the inflammatory effect provoked at human pulp tissue. Conclusions. Calcium-hydroxide (CH) powder and Pro-Root MTA (Dentsply-Sirona) have shown excellent biocompatibility in vitro and in vivo when tested on human cells and teeth. Their use after many years of research and clinical experience seems safe and proven for vital pulp therapy in healthy individuals, given that an aseptic environment (rubber dam isolation) is provided. Although in vitro evidence suggests that most modern hydraulic calcium-silicate cements promote bioactivity when exposed to human dental pulp cells, care should be taken when these new materials are clinically applied in patients, as small changes in their composition might have big consequences on their clinical efficacy. Key findings (clinical significance). Pure calcium-hydroxide powder/saline and the commercial resin-free hydraulic calcium-silicate cement Pro-Root MTA (Dentsply-Sirona) are the best options to provide a complete reparative bridge upon vital pulp therapy. Systematic review registration number. PROSPERO registration number: CRD42020164374.

Physical-Mechanical Properties of a Resin-Modified Calcium Silicate Material for Pulp Capping.

The purpose of this study was to investigate and to compare the physical-mechanical properties of a resin-modified calcium silicate material (TheraCal LC), used for pulp-capping, to MTA (Angelus) and a calcium hydroxide cement (Dycal). Specimens of each material (n=12) were prepared in Teflon molds (3.58 mm x 3 mm) and measured before and after immersion in distilled water for 24 h and 30 days to evaluate the dimensional change. The same specimens were submitted to compressive strength test on a Universal Testing Machine (Instron) (1 mm/min). Root canals were filled with the cements (n=8), and after 24 h, the bond strength (push-out test) to dentin was also assessed on a Universal Testing Machine (1 mm/min). Eight additional specimens of TheraCal LC were prepared to evaluate the bond strength immediately after light curing. Data were analyzed using One-Way ANOVA, and Tukey or Bonferroni post hoc tests (p<0.05). Percentage expansion of TheraCal LC was above the Specification No. 57 of ANSI/ADA, in both periods. The dimensional change for TheraCal LC was higher than MTA in 24 h and 30 days; and Dycal in 30 days (p<0.05). TheraCal LC had higher compressive and bond strength to dentin in comparison with MTA and Dycal (p<0.05). Although TheraCal LC expanded more than the ANSI/ADA recommendation, its compressive and push-out bond strength to dentin were satisfactory and superior to MTA and Dycal.

Hot air stream reduces cytotoxicity of light-cured calcium hydroxide based cements.

BackgroundThe light-cured calcium hydroxide based cements have incomplete polymerization and unconverted monomers can cause pulp cell damage. The aim of this study was to evaluate the influence of a warm and hot air stream on the cytotoxicity of light-cured calcium hydroxide based cements. Material and MethodsThe materials Dycal (conventional cement), Biocal, Hidrox-Cal, and Ultra-Blend Plus (light-cured calcium hydroxide cements) were submitted to cytotoxicity analysis after polymerization, without vs. with previous heat treatment with a warm (37°C) and a hot (60°C) air stream. Following polymerization, cements were maintained in culture medium for 24 hours and 7 days, and subjected to the MTT test. Data were analyzed using analysis of variance (ANOVA) followed by post-hoc Student-Newman-Keuls (<0.05). ResultsThe results indicated significant differences between the materials according to their composition, i.e., light-cured cements treated with a jet of warm air showed similar cytotoxicity levels to those observed for conventional cement, suggesting that they may be considered alternatives in cases requiring pulp-capping treatment. ConclusionsApplication of a hot air stream reduced cytotoxicity of materials tested. Key words:Dental pulp capping, dental cements, calcium hydroxide, cell survival.

The effect of three different pulp capping cements on mineralization of dental pulp stem cells.

This study evaluated the osteogenic differentiation of human dental pulp stem cells in response to substances released by the pulp capping agents, Biodentine (BD), mineral trioxide aggregate (MTA) and two-paste calcium hydroxide cement (CHC), along with their physicochemical characteristics. The dimensional stability test showed that of the materials studied, only BD met the standards recommended by the International Organization for Standardization (ISO) for pulp capping materials and thus can be used safely. In the chemical tests, BD was the most stable material. In the Alizarin red S test, BD formed the higher amount of mineralized nodules in the mineralizing medium and also formed mineralized nodules in a non-mineralizing medium. BD releases substances that can significantly induce formation of the human dental pulp stem cell-mineralized extracellular matrix, with physicochemical characteristics that are more conducive to pulp repair than those of MTA and CHC.

Maintenance of the aseptic working field during endodontic treatment

Objective: The aim of this clinical quality study was to determine whether the aseptic working field is maintained during the endodontic procedure.Materials and methods: Bacterial samples were collected from the rubber dam of 27 patients during endodontic treatment performed by postgraduate students at the Department of Endodontics, University of Oslo. A bacterial sample was first obtained immediately after disinfection of the working field (A), and the second sample was collected just before obturation or dressing with calcium hydroxide cement (B). Aerobic cultivation technique and PCR were used for detection of bacterial growth and species.Results: All samples were negative on culturing except in one case, which showed positive results with cultivation in both sample A and B. Specie detected with cultivation technique were Streptococcus mitis. With PCR technique, 6 samples in 5 patients (11%), showed positive results. Species detected with PCR technique were Bacteroidales spp. Propionibacterium spp., Bacteroidetes spp., Prevotella nigrescens, Haemophilus parainfluenzae, Neisseria elongata, Alloprevotella tannerae, Capnocytophaga granulosa, Cardiobacterium hominis, Fusobacterium nucleatum and Streptococcus mitis.Conclusion: The present study showed that an aseptic working field was maintained throughout the endodontic procedure in 81% (22/27) of the cases after disinfection of the rubber dam.