Journal of Dentistry, Shiraz University of Medical Sciences
Volume:19 Issue: 3, Sep 2018

Statement of the Problem: The rate of antibiotic resistance in bacteria and side effects of antibiotics and oral and teeth health care products are increasing. Therefore, researchers aim at finding new alternatives to control bacteria of dental caries.
The objective of this study was to investigate the inhibitory and bactericidal effects of different concentrations of zinc sulfate and zinc acetate solutions on the main recognized agent of dental caries, Streptococcus mutans.
In this experimental study, different concentrations of aqueous zinc sulfate and zinc acetate solutions were prepared and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these salts for Streptococcus mutans were determined in compare with penicillin, chlorhexidine by micro-serial dilution method. In addition, the diameters of zone of inhibition for these salt solutions in four concentrations along with chlorhexidine, as the control, were detected by the disc diffusion method.
MIC and MBC of zinc sulfate solution were higher than penicillin and chlorhexidine. There were not statistically significant differences between the MIC and MBC of zinc acetate solution, penicillin, and chlorhexidine. In 25 and 50 µg/mL concentrations, the diameters of inhibition zone for zinc sulfate were more than zinc ac
Zinc sulfate and zinc acetate salts with 37.19 and 31.25 µgr/mL concentration had inhibitory effect on Streptococcus mutans growth respectively, although, no priority in antibacterial activity of the studied zinc salts was determined in comparison with penicillin and chlorhexidine.

Statement of the Problem: After introducing digital radiography, practitioners started reading radiographs from computer monitors; however, many still prefer hard-copy radiographs.
This study aimed to assess the possible superiority of either type of radiograph recording media (computer monitor, film, or paper) in diagnosis and perception of the depth of the cariogenic lesions.
Twenty digital bitewing radiographs, obtained from 200 posterior extracted teeth, were displayed on an LG monitor and printed on paper and film using Kodak printers. Two observers independently measured lesions depth on the images. Serial sections of teeth were obtained and the sections were evaluated by a stereomicroscope to determine the actual depth of cariogenic lesions. The efficacy of the each medium was assessed by determining its specificity and sensitivity in comparison with those of histological images. Weighted kappa coefficients and the ROC analysis were used for the statistical analysis.
Strong intra- and inter-observer agreements (0.818 to 0.958, 0.77 to 0.85) were found for all detection methods. The highest Az value was obtained with the monitor-displayed images (Az: 0.879); however, differences between detection methods were not statistically significant (p> 0.05).
Monitor-displayed bitewing radiographs, paper, and film prints used in our study performed similarly in the detection of proximal caries.

Statement of the Problem: Reduced bone mineral density (BMD) generally affects postmenopausal women and it is classified into moderate (osteopenia) and significant osteoporosis. Based on digital panoramic radiographs (DPRs), several quantitative and qualitative assessment methods have been proposed for the diagnosis and evaluation of bone changes and as a predictor of BMD.
The aim of this study was to compare mandibular cortical width (MCW) and mandibular cortical index (MCI) derived from DPRs in evaluating the BMD in osteopenic and osteoporotic post-menopausal women.
In this cross-sectional study, the BMD assessment was performed using dual-energy X-ray absorptiometry (DEXA). Then, patients were divided into two groups: osteopenia and osteoporosis based on WHO criteria. Two types of T-scores including TT (trabecular) for lumbar spine, TC (cortical) for femoral neck and finally, MCW and MCI were measured based on DPRs.
Fifty females with the average age of 57.64±6.03 years were entered into the study. MCW significantly correlated with BMD (p The results showed that MCW is an appropriate index of osteoporosis in post-menopausal women. Although the prediction of osteoporosis is poorer at the femoral neck than lumbar.

Statement of the Problem: Extraction of the impacted third molar is often associated with severe postoperative pains, management of which are a big challenge. Lamotrigine is a new antiepileptic drug with pre-emptive analgesic properties, which is hypothesized to alleviate postoperative pain.
This study aimed to evaluate the efficacy of pre-operative administration of single oral 200 mg lamotrigine in reducing the postoperative pain of impacted third molar surgery.
In this randomized controlled trial, 100 adult patients were divided into two groups (n= 50) to receive either 200 mg oral lamotrigine or placebo 1 hour before the removal of impacted third molar. The patients were monitored for 4 hours in the recovery room and pain intensity was measured through visual analogue scale (VAS) for the next 12 hours at 30-minute intervals. The time and number of rescue analgesics used in 12 hours was also recorded.
Two groups were not statistically significantly different regarding the severity of postoperative pain. (p= 0.512)
Accordingly, pre-emptive administration of lamotrigine was not effective in diminishing the postoperative acute pain of impacted third molar extraction.

Statement of the Problem: It is postulated that attention deficit/hyperactivity disorder (ADHD) with or without medication has an inhibitory effect on the children’s growth and development.
This study aimed to assess the dental age and cervical vertebral maturation (CVM) stage in ADHD patients with or without medication.
This cross-sectional study evaluated the pretreatment panoramic and lateral cephalograms of 129 patients (70 males, 59 females aged 8-14 years). Demirjian index and Baccetti’s CVM index were used to determine the dental age and CVM stage, respectively. The subjects were evaluated in two groups of ADHD (case, n=59) and healthy individuals (control, n=70). The ADHD patients were divided into two groups of AWT (ADHD with Treatment, n=43) and AW (ADHD without treatment, n=16) based on the use of methylphenidate. Paired t-test was used to compare the mean dental age between the groups. Linear and ordered logistic regression models were used to detect differences between the groups. The association between dental and chronological age was assessed by using Pearson correlation coefficient (p After age and sex adjustment, the skeletal maturity stage was found to be similar to the control group based on the presence of the disorder or use of medication (p= 0.711 and p= 0.436, respectively). Similarly, the patients’ dental age was similar to the controls in AW and AWT groups (p= 0.180 and p= 0.421, respectively). The correlation between dental age and chronological age was 0.79 in AWT, 0.88 in AW, and 0.88 in control group (p After age and sex adjustment, the dental and skeletal age of ADHD patients with or without Methylphenidate treatment do no manifest a significant delay compared with the controls.

Statement of the Problem: Considering the limitations of conventional sintering of zirconium oxide (ZrO2) copings, shortening the sintering time can be proposed as an alternative method for making the copings.
This study aimed to assess the effects of sintering time on compressive strength of Yttria Tetragonal Zirconia Polycrystal (Y-TZP) copings.
Thirty copings of pre-sintered 3Y-TZP blanks were milled and sintered in a special furnace for three different durations (n=10 per group). The sintering time was 1 h 15 min for IPS e.max ZirCAD, 4 h 20 min for Speed ZrO2, and 7 h 20 min for the conventional ZrO2 group. The specimens were cemented on the brass dies by using conventional glass ionomer cement. The copings were vertically loaded until fracture by using a universal testing machine. The data were analyzed through one-way analysis of variance (ANOVA) and post hoc test to compare the mean differences of compressive strength yielded in three study groups (α=0.05).
The mean ± SD of compressive strength value was (3617 ± 543.54) N for IPS-e.maxZirCAD group, (2663 ± 508.11) N for Speed ZrO2 group, and (1662± 466.71 N) for conventional ZrO2 group. There were statistically significant differences among compressive strength values of the tested groups (p Within the limitations of this in vitro study, it can be concluded that compressive strength of the zirconia copings is affected by the sintering time. High compressive strength of zirconia copings can be obtained by shortening the sintering time.

Statement of the Problem: Lichen planus disease is a chronic inflammatory lesion without a known etiology. Recent studies have indicated the role of vitamin D on immune system and proposed its anti-inflammatory effects.
This study aimed to compare vitamin D serum levels in patients with oral lichen planus and healthy subjects.
In this case‒control study, 18 patients suffering from oral lichen planus referred to the Department of Oral Medicine, Tabriz Faculty of Dentistry were chosen as the case group and 18 healthy people were chosen as the control group. A 5-mL blood sample was taken from all subjects and the subjects’ vitamin D serum levels were assessed with a vitamin D total (25-hydroxy vitamin D) kit by employing the electrochemiluminescence technique. The results were analyzed and compared by using SPSS17 statistic software. p The mean vitamin D level in serum of patients with oral lichen planus was 30.7±20.38ng/ml and in healthy subjects was 36.45± 15.33ng/ml, the difference was not statistically significant (p= 0.346).
The difference between the level of vitamin D in the serum of patients suffering from oral lichen planus and healthy individuals was not significant.

Statement of the Problem: Oral squamous cell carcinoma is the most common oral malignancy. Toll-like receptor (TLR) activation led to alterations in the levels of mRNA encoding the TLR accountable for recognizing the inducing agonist and cross-regulation of other TLR.
The purpose of this study is determination of mitogen-associated protein kinase (MAPK) activation in human immortalized oral epithelial cell (HIOEC) line via up regulating of TLR7.
expression of TLR7 was measured in HIOEC and normal cells by quantitative real-time polymerase chain reaction (qRT-PCR) and samples were calibrated by β-actin.
Western blot analysis discovered high expression of TLR7 and MAPK in HIOEC cell lines. TLR7 was over-expressed in HIOEC cell line. Imiquimod-induced expression of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF) was inhibited by TLR7 siRNA in HIOEC cells as determined by reverse transcription polymerase chain reaction (RT-PCR). Mean fluorescence intensity of nuclear p38 expression was determined in HIOEC cell lines (p TLR7 is functionally over-expressed in HIOEC cell line of oral squamous cell carcinoma and development of resistance to cisplatin in human oral squamous cell carcinoma might occur through the mechanism involving activation of TLR7 and its dependent signaling pathway.

Statement of the Problem: Oral and general health status depends on several factors such as the individual’s personal attributes, behaviors, and perceptions.
This study aimed to evaluate the factors affecting the oral health-related behaviors in 12-year-old children.
This cross-sectional study was based on the data obtained from 1554 students being 12 years old and from five provinces in Iran. The data were collected with a culturally adapted questionnaire about the students’ demographic characteristics, knowledge, attitudes, and practice (KAP). Path analysis was conducted to evaluate the effect of these factors on oral health-related behaviors in urban and rural areas.
Based on the findings, 61.1% of the samples resided in urban and 38.9% in rural areas. The mean scores were relatively good for knowledge (74.1±21.1%) and attitudes (72.6±21.1%), but unsatisfactory for oral health practice (51.8±12%). Having measured the correlation between the independent variables and oral health-related behaviors, the province of residence and the parents’ education and job had the most significant correlations. Behavioral biases were seen in all dimensions of practice such as brushing habits, dental visits, and diet. In urban areas, 30% and in rural areas 49% of oral health behaviors were directly related to knowledge and attitudes. All of the calculated effects exhibited significant differences from zero (p Path analysis identified some direct and indirect factors influencing the children’s oral health-related behaviors. Factors included in this model could only justify a part of oral health behaviors. Thus, other educational models should be considered based on the psychology or social learning theories.

Statement of the Problem: Periodontal diseases are complex oral diseases characterized by bacterial-induced inflammatory destruction of tooth-supporting tissues. Porphyromonas gingivalis (P. gingivalis) is a common gram-negative anaerobic oral bacteria strongly associated with periodontal disease.
The present study was conducted to estimate prevalence of P. gingivalis in patients with periodontal diseases by using meta-analysis method.
Martials and Different databases including PubMed, EmBase, Scopus, the Institute for Scientific Information (ISI) Web of Science, and the Cochrane Library were searched to identify original English-language studies addressing prevalence of P. gingivalis in periodontal diseases up to December 2014. The random effects model was applied in the meta-analysis and the heterogeneity between studies was assessed using a Cochran test and the I2 index. Funnel plots and Egger test were used to examine publication bias. Statistical analyses were performed using STATA version 12.
Forty-two eligible studies published during 1993- 2016 were selected for meta-analysis. Considering all the included studies, the total sample size was 5,884 individuals containing 2,576 healthy people with a mean age of 37.21±7.45 years and 3,308 periodontal patients with a mean age of 44.16±8.35 years. Overall, the prevalence of P. gingivalis was 78% [95% CI: 74-81] in periodontal diseases group and 34% [95% CI: 26-41] in healthy individuals. There was a significantly higher prevalence of P.gingivalis in individuals with periodontal diseases compared to healthy subjects [78% versus 34%, respectively].
This study indicates that P. gingivalis is highly present in subjects with periodontal diseases and it also appears in periodontally healthy people, although to a lesser extent. Thus, the presence of P. gingivalis increases the chance of periodontal disease and it can be considered as a main potential risk factor.

Dens Invaginatus is a developmental disturbance resulting from abnormal morpho differentiation. It is characterized by an invagination of the enamel and dentin, creating a lumen inside the affected tooth, which may extend as deep as the apical foramen. In the present scenario, calcified Oehler’s type IIIb dens invaginatus in left maxillary lateral incisor in 23-year-old male patient was seen. As the two-dimensional imaging lacks accuracy in such complicated cases, cone beam computed tomography was used to assess the calcification three dimensionally. Endodontic treatment was performed in two visits, using thermoplastized gutta percha obturation technique.

The pursuit of esthetic excellence has become a major goal in the dental treatment and orthodontic treatment. The beauty of the smile is not only constituted by the shape, position, and size of the teeth, but also based on the characteristics of the gingival tissue and conformation of the lips, which should be as harmonious as teeth. Gummy smile is one of the complaints of the patients, since such a situation can influence self-esteem and social relationships. The development of new more conservative techniques may provide a better therapeutic option than surgical procedures, such as the application of botulinum toxin, in the treatment of gummy smile. The purpose of this article is to present the case of a patient who presented dentogingival discrepancy and gummy smile, treated by resective gingival surgery and by application of botulinum toxin, optimizing smile harmony, and achieving improved self-esteem and quality of life. The application of botulinum toxin is an alternative less invasive, faster, safer, and more effective. Moreover, it produces harmonics and pleasing results when applied in target muscles, respecting the appropriate dose and type of smile. Therefore, the technique is a useful adjunct in the esthetic improvement of the smile and provides better results when combined with resective gingival surgery.