The effect of light compressive and tensile mechanical forces on SOST and POSTN expressions in human periodontal ligament cells: an in vitro study.

Periodontal ligament (PDL) cells play an important role in mechanosensing and secretion of signaling molecules during bone remodeling. However, the regulatory mechanism is unknown. The aim of the present study is to investigate the expression pattern of periostin and sclerostin in response to orthodontic forces in periodontal ligament cells in vitro. PDL cells were isolated from extracted teeth and treated with compressive forces of 25 gr/cm2 or equiaxial tension forces at frequency 1 Hz for 0, 24, 48, and 72 h. qRT-PCR was applied to evaluate the gene expressions. The secretion of sclerostin and periostin was assessed using ELISA. DAPI staining was used to evaluate apoptosis. The expression of sclerostin elevated significantly at protein and gene levels under compression forces after 24 h, while the application of tensile forces induced the expression of periostin and its upstream regulator RUNX2 (p < 0.05). Gene expression up-regulation was significant for POSTN and RUNX2 after 48 and 72 h tensile forces. Also, the gene expression of sclerostin reduced in a time-dependent manner after application of tensile force. The compression forces enhanced apoptosis to 7.5 ± 3.5% and induced gene expression of apoptotic markers of CASP9, and BCL2 within 72 h of exposure. Periostin and sclerostin play an important role in orthodontic loads and their expressions are affected oppositely by compressive and tensile forces that might be suggested as a biomarker for assessment of bone remodeling during orthodontic treatment.

Erratum: Effect of amitriptyline on orthodontic tooth movement in rats: An experimental study.

[This corrects the article DOI: 10.34172/joddd.2020.033.].

In Vitro Effect of Photobiomodulation Therapy with 980 nm Diode Laser on Gene Expression of Key Regulators of Bone Remodeling by Human Periodontal Ligament Cells under Mild Orthodontic Forces.

This study investigated the effect of photobiomodulation (PBM) with 980 nm diode laser as monotherapy and in combination with compressive and tensile orthodontic forces on expression of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), sclerostin (SOST) and periostin (POSTN), by human periodontal ligament cells. Isolated cells were cultured and subjected to either tensile (10% elongation) or compressive forces (25 g cm-2 ) for 24 and 48 h. Subsequently, the cells received PBM (100 mW power, 3 or 6 J cm-2 energy density) immediately after load cycle. RT-PCR was applied to assess the genes expression. Data were analyzed by one-way ANOVA, followed by post hoc Tukey test (P ≤ 0.05). We found that PBM in combination with orthodontic forces led to upregulation of bone resorption genes (RANKL and SOST) at the pressure side and their downregulation at the tension side. The expression of osteogenic genes (OPG and POSTN) increased at the tension side and decreased at the pressure side. PBM alone did not affect gene expression. In conclusion, these findings suggest that this PBM protocol may be effective in enhancement of the gene expression in favor of bone remodeling acceleration that should be confirmed in future animal and human studies.

Effect of Hemostatic Agents on Shear Bond Strength of Orthodontic Eyelets Bonded with Conventional and Self-etch Adhesives.

Statement of the Problem: The risk of debonding of the orthodontic eyelets due to blood contamination from the impacted tooth is a clinical problem that orthodontists face routinely. Purpose: This study aimed to assess the effect of hemostatic agents (Viscostat clear and Astringedent X) on shear bond strength (SBS) of orthodontic eyelets bonded with conventional (Transbond XT) and universal adhesive (GC-G Premio bond) adhesives. Materials and Method: In this experimental study, 84 freshly extracted bovine lower incisors were randomly divided into 7 groups namely TBXT, Blood, SEP, VISCO + TBXT, VISCO + SEP, ASTX + TBXT, and ASTX + SEP groups. In the TBXT group, teeth were etched with phosphoric acid gel, and then, the Transbond XT primer was applied and eyelets were bonded with Transbond XT. In the blood group, first, contamination with blood was done followed by the same procedure as TBXT. In other groups, the teeth were etched with phosphoric acid and based on their group allocation, Transbond XT primer (in TBXT groups), GC-G Premio Bond (in SEP groups), ViscoStat Clear gel (in VISCO groups), or Astringedent X (in ASTX groups) were applied. The SBS was measured for each group and the adhesive remnant index (ARI) was determined. Results: The mean SBS was 20.79 MPa in VISCO+SEP group, 19.2 MPa in the TBXT group, 16.06 MPa in the SEP group, 15.43 MPa in VISCO+TBXT group, 9.39 MPa in AST-X+TBXT group, and 1.62 MPa in the blood group. The SBS of ASTX+SEP, blood and TBXT+ASTX groups had significant differences from the SBS of the control group (p< 0.05). The ARI score of 0 had the highest frequency in the blood group. Conclusion: Due to the high coagulative effect of Astringedent X and acceptable SBS of Astringedent X in combination with GC-G Premio bond, this combination can be recommended for exposure of impacted teeth that are at high risk of blood contamination.

Antimicrobial effects and mechanical properties of poly(methyl methacrylate) as an orthodontic acrylic resin containing Curcumin-Nisin-poly(L-lactic acid) nanoparticle: an in vitro study.

BACKGROUND: The porous surface of acrylic orthodontic removable appliances creates a niche for microbial plaque accumulation, and changes the oral flora by raising cariogenic bacteria including Streptococcus mutans. In this study, we evaluated the mechanical properties and antimicrobial activities of incorporating different concentrations of Curcumin-Nisin-poly(L-lactic acid) nanoparticle (CurNisNps) into orthodontic acrylic resin against Streptococcus mutans and Candida albicans. METHODS: Following synthesis and characterization of CurNisNps, acrylic resin specimens with different concentrations of CurNisNps (0, 1, 2, 5, and 10% w/w) were fabricated. Flexural strength values, antimicrobial effects, anti-biofilm potential, and anti-metabolic activity against S. mutans and C. albicans were assessed at different time intervals. Also, the expression of the virulence-factor-related genes of S. mutans and C. albicans was assessed by quantitative real-time polymerase chain reaction following treatment with CurNisNps. RESULTS: Acrylic resin containing 10% CurNisNps (30.76 ± 3.91 MPa) showed flexural failure in comparison with acrylic resin specimens without CurNisNps (50.67 ± 1.82 MPa) as the control group (P < 0.05). There was no significant decrease in the flexural strength values in samples containing 1, 2, and 5% of CurNisNps in comparison to the control group (P > 0.05). Acrylic resin with 5% CurNisNps showed the highest concentration of CurNisNps and clinically accepted flexural strength value (14.89 ± 3.26 MPa, P < 0.05) simultaneously. In the disc agar diffusion assay, 5% CurNisNps showed a high level of inhibitory activity for the test microorganisms. The reduction of growth inhibition zones of the different concentrations of CurNisNps against test microorganisms was positively associated with the time, in such a way that it was reduced significantly after 60 days. The anti-biofilm and anti-metabolic activities of acrylic resin specimens containing a 5% concentration of CurNisNps against S. mutans and C. albicans could significantly decrease the expression levels of gtfB (6.8-fold) and HWP (3.4-fold) in S. mutans and C. albicans, respectively. CONCLUSIONS: Our data support that 5% (w/w) of CurNisNps can serve as an excellent orthodontic acrylic resin additive against S. mutans and C. albicans biofilm without adverse effects on its mechanical property.

The ethical attitude of dentists scale: development and psychometric properties.

One critical tactic that leads to a better understanding of the ethical status of dentists is to assess their ethical attitude by using an appropriate scale. This study aimed to design and evaluate the validity and reliability of the ethical attitude of dentists scale (EADS). This study was conducted based on a mixed-method design. The first qualitative part of the study was conducted in 2019 and the items of the scale were produced from the ethical codes compiled in a previous study. In this part, the psychometric analysis was conducted. The reliability was evaluated by Cronbach's alpha coefficient and intraclass correlation coefficient. Factor analysis was used to assess the construct validity (n = 511), and the following three factors were extracted with a total variance of 48.03. 1) Maintaining the standing of the profession in relationships. 2) Providing dental services while maintaining trust in the profession, and 3) Providing information for the benefit of the patient. In confirmatory factor analysis, appropriate values were obtained for the goodness of fit indices, and Cronbach's alpha was 0.68 - 0.84 for the various factors. Based on the results mentioned above, this scale showed an appropriate validity and reliability for measuring the ethical attitude of dentists.

Comparative assessment of the orthodontic wire's friction coated with zinc oxide nanoparticles by two methods of chemical precipitation and hydrothermal process.

INTRODUCTION: In orthodontic treatment with sliding technique, reduction of frictional forces could result in a more effective treatment. Recently, wire coating with nanoparticles were proposed to reduce frictional forces.

Effect of amitriptyline on orthodontic tooth movement in rats: an experimental study.

Background. Orthodontic tooth movement (OTM) occurs in the alveolar bone; therefore, any condition affecting bone quality can alter OTM. This study aimed to evaluate the effect of amitriptyline on OTM in rats. Methods. Forty-five male Wistar rats were randomly divided into three groups: (I) no injection, (II) injection with saline solution, and (III) injection of amitriptyline. Next, a 60-gr force was applied to the maxillary left first molar tooth of all the rats, using a nickel‒titanium closed-coil spring ligated between the maxillary incisors and the left first molar tooth. The rats were sacrificed after 21 days to measure OTM and perform histological analysis to determine the number, width, and depth of resorptive lacunae, osteoclast counts, and periodontal ligament (PDL) width. Results. The highest and the lowest OTM rates were found in the control and amitriptyline groups, respectively; however, there was no significant difference between the study groups in this regard. Histological analysis showed a significantly lower number of resorption lacunae in the amitriptyline group than the saline group. Conclusion. Although no significant difference was noted in OTM after amitriptyline administration, a reduction in the number of resorptive lacunae in rats injected with amitriptyline suggests that amitriptyline affects the bone tissue at the cellular level.

Evaluation of the Shear Bond Strength and Adhesive Remnant Index in Debonding of Stainless Steel Brackets Assisted with Nd:YAG Laser Irradiation.

OBJECTIVES: The purpose was to compare shear bond strength (SBS), pulp temperature, and adhesive remnant index (ARI) in debonding of stainless steel brackets from enamel surface using neodymium-doped yttrium aluminum garnet (Nd:YAG) laser versus the conventional debonding method. MATERIALS AND METHODS: Forty-eight extracted premolars were bonded to stainless steel brackets. The samples were divided into three experimental groups and one control group. In the first three groups, Nd:YAG laser was used for debonding with the power of 1, 1.5, and 2 W, respectively, for 10 seconds. The SBS and ARI of the samples were assessed. Pulp temperature was recorded before and after irradiation. Two samples from each group were used for determining enamel morphology after debonding using scanning electron microscopy (SEM). RESULTS: The mean SBS in the groups was 33.05, 28.69, 24.37, and 31.53 MPa, respectively, with no statistically significant differences (P=0.205). Significant differences in post-irradiation temperature were noted among the lased groups (P=0.000). Debonding mainly occurred at the adhesive-enamel interface in the 1-W laser and control groups and at the bracket-adhesive interface in the 1.5-W and 2-W laser groups. Enamel structure was amorphous and irregular following laser irradiation. CONCLUSION: Based on the results of this study, the use of Nd:YAG laser could not significantly affect the SBS. Therefore, this laser would not be suitable for debonding of metal brackets. The use of a 2-W laser could significantly raise the pulpal temperature. Nd:YAG laser renders a more heterogeneous enamel morphology compared to conventional debonding methods.

Design and Development of Dentistry Ethical Codes: Proposed for National Implementation in Iran.

OBJECTIVES: The dental profession has a special place of trust in the society, and dental clinicians must adhere to ethical standards in all dental procedures. Ethical conduct is one of the main expectations of individuals from this profession. The aim of this study was to design and develop dental ethical codes for national implementation in Iran. MATERIALS AND METHODS: This qualitative study was performed using directed content analysis method and purposive sampling. Data were collected until saturation through 15 semi-structured face-to-face individual interviews and two expert panels with academic staffs from dental faculties in Tehran, Iran. RESULTS: Data were classified into five principles and 90 codes. The principles included consideration of patients' interest as a priority, respect for human dignity and patient autonomy, confidentiality of patient information, the excellence of knowledge and skills, and building trust. CONCLUSION: The ethical codes for Iranian dentists were drafted considering Islamic teachings and the prevailing culture. Some codes were exclusively developed for the cultural atmosphere of Iran especially on topics such as interaction with patients previously treated by other dentists. Some codes addressed the principles of consultation and continuing the therapeutic communication with such patients. Some items have not been considered in codes released by other associations, such as religious considerations in Islamic cover and alcohol consumption that were taken into consideration in this draft. These codes can serve as a guide for professional practice of dentists. It seems that these sets can help us reach the standardized code.

Decreased bone density induced by antiepileptic drugs can cause accelerated orthodontic tooth movement in male Wistar rats.

PURPOSE: The aim of the present study was to evaluate the effect of the carbamazepine and valproic acid on orthodontic tooth movement in male Wistar rats. METHODS: Evaluation of tooth movement after 21 days of drugs infusion was carried out by feeler gauge. Bone densitometry on lateral cephalograms was conducted on days 1 and 21. After dissection of the maxillae, histologic parameters were evaluated. RESULTS: Orthodontic tooth movement was accelerated in experimental groups rather than controls. Optical density was significantly increased in these groups. In histologic sections, mesioapical portion of the PDL (Periodontal Ligament) was wider in experimental groups. Also, distoapical portion of the PDL was wider only in valproic acid group. CONCLUSION: Valproic acid and carbamazepine can decrease the bone density which may induce the accelerated orthodontic tooth movement in rats.

Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study.

OBJECTIVES: In clinical conditions, orthodontic brackets are exposed to periodic stresses mainly induced by mastication and intraoral forces. The objective of the present study was to evaluate the effects of cyclic loading to simulate masticatory forces on shear bond strength (SBS) of metal brackets bonded to teeth using self-etch and total-etch bonding systems. MATERIALS AND METHODS: Eighty-four caries- and crack-free bovine mandibular incisors were selected and randomly assigned to two groups based on the type of bonding system. After bonding, all samples were thermocycled (500 cycles) followed by cyclic loading of the half of the specimens in each group by applying 40 N load with 2 Hz frequency for 10,000 cycles. The SBS was measured using a universal testing machine. The adhesive remnant index (ARI) score was calculated subsequently. Data were analyzed using Kolmogorov-Smirnov test, two-way ANOVA and Mann-Whitney test. RESULTS: The SBS was 10.09±3.78 MPa and 14.44±6.06 MPa for self-etch and total-etch bonding systems in cyclic loading group, respectively. The SBS was 9.43±5.3 MPa and 11.31±5.42 MPa in self-etch and total-etch groups without cyclic loading, respectively. Cyclic loading did not cause any significant difference in SBS (P>0.05). The ARI scores of the groups were significantly different (P<0.05). CONCLUSIONS: The present results demonstrated that low masticatory forces at 10,000 cycles did not have a significant impact on bracket-adhesive SBS; however, they significantly changed the ARI score. Even though the total-etch bonding system yielded higher SBS than the self-etch system, the performance of both was clinically acceptable.

Comparison of Enamel Morphologic Characteristics after Conditioning with Various Combinations of Acid Etchant and Er:YAG Laser in Bonding and Rebonding Procedures: A SEM Analysis.

OBJECTIVES: Many studies have evaluated re-etched enamel by using scanning electron microscopy (SEM); however, there is no evidence regarding the use of Erbium-doped yttrium aluminium garnet (Er:YAG) laser at primary and secondary bonding instead of acid etching with regards to enamel surface changes. The purpose of the present study was to determine that whether or not the methods of primary and secondary enamel preparation affect enamel characteristics after rebonding, by using SEM analysis. MATERIALS AND METHODS: Twelve freshly extracted premolars were divided into 4 groups. The samples in each group were conditioned by acid etchant or Er:YAG laser at primary conditioning, according to the instructions. Afterwards, they were bonded with orthodontic brackets. After debonding, the samples were prepared for second conditioning. Also, two samples were conditioned only once with acid etchant or laser, to compare enamel morphology changes with those after re-etching. Finally, buccal enamel surfaces were evaluated using SEM. RESULTS: Enamel etching patterns were observed in the samples which had been acid-conditioned at first or at both conditionings. The samples irradiated by Er:YAG laser showed amorphous and irregular surfaces, with no signs of typical etching patterns. A large deep gap was seen in one of the samples irradiated with laser at primary and secondary conditionings, which might have penetrated the underling layers of enamel and dentin. CONCLUSIONS: Enamel surface preparation with Er:YAG laser produces irregular and indistinct morphologic changes, completely different from those produced after acid etching at both conditioning and reconditioning. Therefore, it is recommended to use this laser with caution to avoid permanent enamel damage.

Effect of supplementary zinc on orthodontic tooth movement in a rat model.

INTRODUCTION: Osteoclasts and osteoblasts are responsible for regulating bone homeostasis during which the trace element zinc has been shown to exert a cumulative effect on bone mass by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption. OBJECTIVE: The aim of the present study was to investigate the effects of zinc (Zn) on orthodontic tooth movement (OTM) in a rat model. MATERIAL AND METHODS: A total of 44 male Wistar rats were divided into four groups of 11 animals each and received 0, 1.5, 20 and 50 ppm Zn in distilled water for 60 days. In the last 21 days of the study, nickel-titanium closed coil springs were ligated between maxillary right incisors and first molars of all rats, and tooth movement was measured at the end of this period. Histological analysis of hematoxylin/eosin slides was performed to assess root resorption lacunae, osteoclast number and periodontal ligament (PDL) width. RESULTS: Mean OTM was calculated as 51.8, 49.1, 35.5 and 45 µm in the 0, 1.5, 20 and 50 ppm zinc-receiving groups, respectively. There were no significant differences in neither OTM nor histological parameters among the study groups (p > 0.05). CONCLUSION: According to the results obtained in the current investigation, increase in supplementary zinc up to 50 ppm does not affect the rate of OTM neither bone and root resorption in rats.

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.

PubMed-Indexed Dental Publications from Iran: A Scientometric Study.

OBJECTIVES: Scientometric methods and the resulting citations have been applied to investigate the scientific performance of a nation. The present study was designed to collect the statistical information of dental articles by Iranian authors published in PubMed. MATERIALS AND METHODS: We searched the PubMed database for dental articles of Iranian authors until June 31, 2015. All abstracts were manually reviewed in order to exclude false retrievals. The number of articles per dental subspecialties, distribution of research designs, Scopus/Google Scholar citation of each article, number of authors and affiliation of the first/corresponding author were extracted and transferred to Microsoft Excel. The data were further analyzed to illustrate the related scientometric indicators. RESULTS: A total of 3,835 articles were retrieved according to the selection criteria. The number of PubMed-indexed publications between 2008 and 2015 showed a seven-fold increase. The majority of articles were written by four authors (24.56%). Systematic reviews and clinical trials constituted 9.20% of all publications. The number and percentage of articles with ≥4 citations from Google Scholar (n=2024; 52.78%) were higher than those from Scopus (n=1015; 26.47%). According to affiliated departments of the first authors, the top three dental subspecialties with the highest number of publications belonged to endodontics (19.82%), orthodontics (11.13%) and oral and maxillofacial surgery (10.33%). Moreover, the majority of articles originated from Shahid Beheshti- (14.47%), Tehran- (13.72%) and Mashhad- (12.28%) University of Medical Sciences. CONCLUSIONS: Analysis of PubMed-indexed dental publications originating from Iran revealed a growing trend in the recent years.

Assessment of the Role of NO-cGMP Pathway in Orthodontic Tooth Movement Using PDE5 Inhibitors: An Animal Study.

OBJECTIVES: Nitric oxide (NO) is a signaling molecule that mediates mechanical bone loading. Cyclic guanosine 3', 5' monophosphate (cGMP) is a NO-induced effector molecule. The aim of this study was to assess the effect of NO-cGMP pathway on orthodontic tooth movement (OTM) in rats by use of two phosphodiesterase 5 (PDE5) inhibitors namely sildenafil and tadalafil as chemical tools. MATERIALS AND METHODS: Forty-five male Wistar rats were divided into three equal groups (n=15) based on the substance they received. The first group received daily injections of tadalafil; the second group received daily injections of sildenafil and the third group received daily injections of normal saline. The orthodontic appliances consisted of nickel-titanium closed-coil spring ligated between the maxillary right incisor and the first molar of the animals for 21 days. The amount of tooth movement was measured in all three groups at the end of this period. Histological analysis was performed to assess root resorption lacunae, osteoclast number and periodontal ligament (PDL) thickness. RESULTS: All appliance-treated molars in the experimental and control groups showed evidence of tooth movement. The mean OTM was calculated to be 0.39±0.16, 0.32±0.16 and 0.26±0.16mm in tadalafil, sildenafil and control groups, respectively and there were no significant differences in OTM among the study groups (P>0.05). In the tadalafil group, significantly greater root resorption on the tension side was seen when compared with controls (P≤0.05). CONCLUSIONS: Tadalafil and sildenafil PDE-5 inhibitors affecting the NO-cGMP pathway did not affect OTM in rats.

Prevalence of blood-borne viruses among Iranian dentists: Results of a national survey.

OBJECTIVES: Health care workers, including dentists, are at the front line for acquiring blood-borne virus infections. This study aimed to investigate the prevalence of hepatitis B, hepatitis C and human immunodeficiency viruses among Iranian dentists. MATERIAL AND METHODS: The survey included 1628 dental health care workers who attended the 51st annual Congress of the Iranian Dental Association. Data on the risk of blood-borne virus transmission during health care and infection control practices were gathered from self-administered questionnaires. Sera were screened serologically by enzyme-linked immunosorbent assay (ELISA). The positive samples were examined by polymerase chain reaction (PRC) followed by direct sequencing. RESULTS: Six (0.36%) and 81 (5.0%) were positive for hepatitis B surface antigen (HBsAg) and (anti-hepatitis B virus core antigen (anti-HBc), respectively. Only 1 (0.061%) was positive for anti-hepatitis C virus (anti-HCV). No case was positive for anti-human immunodeficiency virus (anti-HIV). One case was diagnosed as being occult hepatitis B virus (HBV) infection. One thousand five hundred thirty-five (94.3%) of participants had received at least 1 dose of HBV vaccine. One thousand three hundred fifty-nine (88.5%) contained hepatitis B surface antibody (anti-HBs) > 10 IU/ml, of whom 55 (4.0%) were anti-HBc positive, suggesting that they had been infected with HBV in the past. Anti-HBc positive cases had past histories of hepatitis, either their own or their spouses'. Individuals with inadequate anti-HBs levels (< 10 IU/ml) were significantly more prevalent among anti-HBc positive cases (p < 0.001). CONCLUSIONS: The prevalence of blood-borne viruses among dental HCWs found in this study was lower than past reports from Iranian dentists and general population. The implementation of HBV vaccination together with improvement in infection control procedures has reduced the potential for risk infection among Iranian dentists.

HBV vaccination status and response to hepatitis B vaccine among Iranian dentists, correlation with risk factors and preventive measures.

BACKGROUND: Studies showed that HBV vaccination and consequent level of antibody are not completely adequate among dentists despite performance of highly exposure prone procedures. OBJECTIVES: The objectives of the study were to evaluate the levels of responsiveness to HBV vaccine and to determine the occupational factors associated among dental staff. MATERIALS AND METHODS: In total, 1612 dental health care workers were recruited. The level of anti-HBs was tested using a commercially enzyme-linked immunosorbent assay (ELISA). Data on demographic, risk factors associated with dental practice and level of protective procedures and occupational exposure aspects were collected through self-reported questionnaires. RESULTS: Of 1538 vaccinated individuals, 55 (3.7%), 126 (8.4%) and 1309 (87.9%) had received one, two and full three doses of vaccine, respectively. One-hundred-seventy-six (11.5%) were nonimmune (anti-HBs < 10 IU/mL) and 1362 (88.5%) were immune (anti-HBs > 10 IU/ mL). 392/542 (72.3%) of dentists who received their third dose of vaccination less than five years before the commencement of study were completely immune compared to those who had completed all three recommended doses in a longer period (308/491, 64.3%) (P = 0.001). Fifty-eight (3.59%) of participants did not receive any HBV vaccine at all; however, they had positive results for anti-HBs, indicating a past HBV infection. Statistically, the levels of anti-HBs were significantly associated with gender, age, duration of dental practice engagement and regularly use of mask, glasses and shield. CONCLUSIONS: Since dental care workers have a high risk of exposure to hepatitis virus, they should be advised to receive hepatitis B vaccine and it should be confirmed if they have acquired immunity to HBV by testing the level of anti-HBs.