Caspian Journal of Dental Research
Volume:8 Issue: 1, Mar 2019

Following dental avulsion, the immediate recommended treatment is tooth replantation to avoid adverse effects. Therefore, the tooth must be stored in a physiological storage medium to preserve the viability of the periodontal ligament fibroblast (PDLF) cells during transportation to dental office. The aim of this study was to determine the effect of several storage media in preserving the viability of human PDLF cells at different times and temperatures. In this experimental study, the human PDL cells were obtained from the healthy extracted third molars and cultured in Dulbecco's Modified Eagle Medium (DMEM). The studied media were DMEM (10% FBS + 1% penicillin G Na (10000 IU) + 1% streptomycin (10 mg)), tap water, sterilized whole milk, zero fat milk and soy milk. After the cells had reached sufficient density in the plate, they were added to the experimental media and kept at 1, 2, 4 and 24 hours at 4° and 37oCentigrade. After incubation, the cell viability was determined by tetrazolium salt-based colorimetric (MTT) assay. The results were statistically analyzed  using Kruskal–Wallis and post hoc Tests. Whole milk and DMEM showed significantly higher protective effect than other media. The viability of PDL cells had significant difference at 4oC compared to 37oC at 4 and 24 h in DMEM group and at 24 h in whole milk group (p≤0.05). The results have suggested that the whole milk like DMEM have enough essential nutrients for PDLFs and have confirmed the hypothesis that the milk similar to HBSS or DMEM might be effective in preserving the PDLF cells.

The use of dental ceramics has increased due to their beauty and biocompatibility. The aim of this study was to evaluate the effect of hydrofluoric acid concentration and etching time on microtensile bond strength (μTBS) of the Enamic and Suprinity ceramics. In this in vitro study, two hydrofluoric acid (HFA) concentrations of 5% (A) and 10% (B) were used at the time of 20, 60 and 120 seconds (s) on the Suprinity and  Enamic ceramics of CAD/CAM. The etched surfaces were impregnated with silane coupling agent as well as priming and Clearfil SE bond. Then, the Panavia F 2.0  resin cement was applied on the ceramic surfaces and light-cured. There were groups of EA20, EA60, EA120, EB20, EB60, EB120 for Vita Enamic and SA20, SA60, SA120, SB20, SB60, SB120 for Vita Suprinity. The μTBS between resin cement and porcelains was measured with universal testing machine. Mode of failure was observed under the stereo microscope at 40x magnification. Data were analyzed using ANOVA and Chi-square. The μTBS was significantly different between EB20 and EB60 (p=0.008), EB120 and EB20 (p=0.005), SA120 and SB120 (p=0.013), EA120 and EB120 (p=0.002) as well as EA60 and EB60 (p=0.44). In both ceramics, different concentrations and etching times had significant effect on the mean of μTBS (p=0.016). In both ceramics, the time had no effect on the failure mode. For Suprinity ceramic, the HFA concentration had effect on the failure mode (P=0.028). The best surface treatment for Suprinity ceramic is 120 s with 5% HFA and for Enamic is 20 s with 10% HFA, which create the highest bond strength.

Healthy primary teeth are necessary for a child's physical and mental health. Increasing mothers’ awareness of the importance of these teeth is significant for the creation of healthy teeth in their children's mouths. Thus, the aim of this study was to evaluate mothers’ awareness of the importance and care of their children’s primary teeth in Yasuj In this cross-sectional study, 384 mothers with their children aged ≤6 years were enrolled. The data were collected via a 12-item researcher-made questionnaire and analyzed using mean, standard deviation, Spearman and binary logistic regression tests. The mean age of mothers was 29.71±5.04 years. The mean score of mothers’ awareness of the importance of primary teeth was 5.9±2.76 ) score of  0-12).No mothers had good awareness, 119 (31%) and 265 (69%) mothers had moderate and poor awareness in this regard, respectively. A significant relationship was found between mothers’ age and awareness (p=0.0001, r=0.18) as well as between parental education level and awareness (p=0.0001, r=0.25). Parental education levels including subdiploma P=0.009, EXP (B)=15.19, 0.95% CI= 1.97-116.91; diploma and technician P=0.0001, EXP (B)=39.42, 0.95% CI= 5.03-308.81; Bachelor’s degree P=0.001, EXP (B)=27.02, 0.95% CI= 3.55-205.73; Master’s degree and higher P=0.003, EXP (B)=26.26, 0.95% CI= 2.95-233.26 as well as maternal age P=0.008, EXP (B)=1.07, 0.95% CI= 1.02-1.14  were predicting factors for mothers’ awareness of the importance and care of the primary teeth. Considering the undesirable level of mothers’ awareness of the importance and health, the interventions  and planning are essential to enhance mothers’ awareness in this regard.

The aim of the current study was to evaluate the frequency of accessory foramina in human mandible. In this cross-sectional study, 400 cone-beam computed tomography (CBCT) scan images of mandibles of 273 patients (120 males and 153 females), divided into four groups ≤30, 30–39, 40–49, and ≥50 years) with the mean age of 38.05±13.71 years (40.71±12.83 for males and 35.39±12.05 for females) were evaluated. The number and diameter of accessory foramina from midline to anterior border of ramus with 0.1 mm intervals were investigated.Data were analyzed with SPSS 17 (SPSS Inc., Chicago, I1, USA) using T-Test, Pearson's correlation coefficient and Fisher exact test. Totally, 568 accessory foramina with mean diameter of 0.35 ± 0.15 mm were seen. The frequency  of accessory foramina in the studied patients  was 83%  with mean frequency of 88% in males and 80% in females. These results showed a significant difference between the genders in frequency of accessory foramen (P<0.001) although no difference was observed among different age groups. The highest frequency belonged to anterior lingual of mandible. The frequency  of accessory foramina in posterior mandible was higher in females, while males indicated higher frequency in anterior mandible. No significant difference was found in the frequency of accessory foramina between the right and left sides of the mandible. The results suggested,the survey of accessory foramina is recommended in CBCT images of mandible for therapeutic reasons due to higher frequency of accessory foramina in mandible.

Most of the materials used in endodontic procedures may lead to discoloration.This study compared the discolorations induced following treatment by MTA, CEM ,and Biodentine using a spectrophotometric analysis. In this experimental study Forty extracted mandibular anterior teeth were selected and sectioned from 2 mm below Cemento Enamel Junction(CEJ) using a disc. A retrograde method was used for drilling cavities 2 mm away from incisal edge. Then the cavities were washed using 5.25% NaOCL and normal saline and the samples were divided randomly into 4 groups. The cavities in groups 1, 2, and 3 were filled by MTA Angleus, Cem cement, and Biodentine, respectively as deep as CEJ level and they were sealed by 2mm of A3 composite color. All of cavities of group 4/control, were all filled by composite A3. Then the samples were stored in a glass incubator with 100% humidity and  under laboratory light .they were exposed to a spectrophotometric analysis within 6 periods from placement including base line, 1 week, 2 weeks, 1 month, 3 months, 6 months. The data were analyzed by SPSS 17 ,Tukey HSD and ANOVA statistical test. The results showed no statistically significant difference in discoloration rate during measurement periodsin each group. However, the discoloration rate varied in various materials. The minimum and maximum discolorations occurred in Biodentine and MTA, respectively and their difference was statistically significant.(p=0.033)Other groups showed no statistically significant difference. The biodentinehad minimum discolorations compared with other two materials; thus, it seems that it can be recommended for cosmetic areas.

Soft liners are materials used in removable dental prostheses to maintain the health of inflamed mucous membranes. The materials bond strength to acrylic bases can be modified by several methods; One of which includes sandblasting. The aim of this study is to investigate the effect of sandblasting on the tensile bond strength(TBS) of two permanent silicone soft liners. 36 dumbbell-shaped heat-cured polymethylmethacrylate acrylic specimens were fabricated in denture flasks with a length of 75 mm, width of 12 mm and a thickness of 7 mm in the thinnest section. 3 mm of the material of all specimens was cut using a low-speed diamond saw with water cooling. Then according to the surface treatment and sofliners, the specimens were divided into four groups: no surface treatment with mollosil softliner, no surface treatment with GC softliner,  sandblasting with 50 μm Al2O3 particles and then using  mollosil soft liner and sandblasting with 50 μm Al2O3 particles and  then using GC soft liner. After polymerization of all specimens, TBS was evaluated with universal testing machine at a crosshead speed of 5 mm/min until failure. Finally, two-way ANOVA and independent T-test were used to analyzing the data.  The mean of TBS in the groups of sandblasting was significantly higher than other group and the mean of TBS  in the group of mollosil was higher than GC group with or without sandblasting. (p=0.001) Sandblasting increases the TBS of silicone soft liners to the acrylic bases; moreover, Mollosil softliners are more tenacious compared to GC.

Regarding the lack of data on the  frequency of oral cancer in Babol, the aim of this study was to evaluate the frequency of oral cancer in Babol during 2012-2016. This retrospective cross-sectional study was performed using pathology sheet records of oral cancer patients during 2012-2016. Survival status of patients was collected through telephone contact. The mean age of 48 patients was 62.2% (22-95) years, and 64.2% were male. Squamous cell carcinoma (SCC) was the most prevalent malignancy, and the most common site was tongue followed by pharynx. Frequency of oral cancer patients was 9 (18.8%), 9 (18.8%), 10 (20.8%), 12 (25%) and 8 (16.7%) patients from 2012 to 2016, respectively. SCC, specifically on the tongue was the most frequent malignancy. It seems that the oral cancer prevention training is necessary for elderly adults.

Knowledge of the internal anatomy and apical foramen of a tooth has always been a fundamental prerequisite for root canal therapy.Aim of the present study was to evaluate the distance of apical foramen in relation to the anatomical apex of mandibular molars by cone beam computed tomography (CBCT) in a selected Iranian population. In this cross- sectional study,97CBCT images of 25-50 years old patients were evaluated .the teeth were assessed in coronal plan. Average (±SD) distance from apical foramen to the anatomical apex in the mesio-buccal and mesio-lingual, distal canal  were [0.938 (±0.294)mm], [0.964 (±0.315)mm] and [0.982 (±0.322)mm] respectively. no statistical difference was found  between right and left quadrant. This study demonstrated  that  1mm distance from radiographic apex in mandibular molars could be appropriate for root canal therapy.