Dental Research Journal
Volume:16 Issue: 2, Mar-Apr 2019

Low levels of estrogen can cause osteoporosis and usually occur during a woman’s menopausal phase. Osteoporosis can lead to bone resorption, the absence of osseointegration, and implant failure. The aim of this study is to determine the expression of transforming growth factor‑beta 1 (TGF‑β1), runt‑related transcription factor (RUNX2), and osteoblasts in mandibular rats with low levels of estrogen. This study is an in vivo experimental research. Female Wistar rats (n = 18) were divided into two groups: (1) Postsham surgery and (2) ovariectomy group. After 12 weeks, the rats were sacrificed to identify the level of estrogen, while histological analysis was conducted to determine the level of osteoblast and the expression of TGF‑β1 and RUNX2. The data were analyzed using t‑test (P < 0.05). There were significant lower levels of estrogen and osteoblast among the ovariectomy group compared to the postsham group (P < 0.05). RUNX2 levels were found to be significantly higher in the ovariectomy group than that in the postsham group (P < 0.05). However, there were no significant differences between TGF‑β1 levels within the ovariectomy and postsham groups (P > 0.05). Ovariectomy can lead to decreased osteoblastogenesis in mandibular bone by the reduced level of osteoblast and the increased expression of TGF‑β1 and RUNX2.

The degree of tooth enamel wear is an important aspect of the clinical acceptability of all‑ceramic restorations. The purpose of this study was to compare the degree of enamel wear by feldspathic porcelain and polymer‑infiltrated ceramic. In this in vitro study, 10 polymer‑infiltrated ceramics were prepared by creating the sections of Vita Enamic® blocks (18 mm × 14 mm × 4 mm). A total of 10 porcelain cylinders were built, and feldspathic porcelain (VMK 95, Vita) was used and fired over the metal discs. A total of 20 human maxillary premolars were assigned as antagonist. Then, 10 teeth were arranged and placed oppose to porcelain samples and 10 others were placed oppose to polymer‑infiltrated‑ceramic specimens in the chewing simulator. The samples were photographed before and after the chewing simulation. The difference between the two photograph was measured by stereomicroscope and Motic Image plus software 2.0 three times, and then, the mean of these three times was recorded as the amount of wear. Data were analyzed using independent samples t‑test and SPSS version 16. The level of significancy was 0.05. The mean wear rate teeth oppose to the feldspathic porcelain group (377.294 μ) was significantly higher than that of the polymer‑infiltrated ceramic group (101.755 μ) (P = 0.002). In the present study, the amount of enamel wear of the natural teeth opposed to polymer‑infiltrated ceramic was significantly lower than feldspathic porcelain.

This study aims to compare the antimicrobial activity of theobromine and two commercially available kid’s fluoride toothpastes. In this in vitro study a chocolate‑based nonfluoride toothpaste, Theobromine (Group A) and two commercially available kid’s fluoride toothpaste, Kidodent (Group B), Colgate kids toothpaste (Group C) were used in this study. Freeze‑dried stock culture of the strains of Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, and Candida albicans was cultured in their respective selective media. Dentifrices were added to the wells punched out in the culture media and incubated. The zones of inhibition were measured to find out the antimicrobial activity. all data statistically analyzed SPSS using Kolmogorov–Smironov and Shapiro–Wilk’s tests. one‑way ANOVA was done and Turkey’s honest significant difference post hoc test was done for pairwise comparison P ≤ 0.001. Theobromine showed a greater zone of inhibition, which was statistically significant when compared to other two kid’s fluoride toothpastes. Theobromine shows more antimicrobial effect against S. mutans, L. acidophilus, and E. faecalis, whereas almost a neutral effect with C. albicans. Theobromine though nonfluoridated toothpaste showed greater zones of inhibition than other commercially available fluoridated kid’s toothpastes.

In saliva, neutrophil constitutes the most prominent first‑line defense of immune cells against pathogenic microbes. The importance of neutrophils to the host immune systems of neutropenic or patients disabled with regard to their neutrophil function results in a tendency toward serious infections, such as early childhood caries (ECC). The cytoplasmic granules present in neutrophils play a major role in neutrophil‑mediated inflammation. Azurophilic granules contain antimicrobial proteins, such as defensin, a human antimicrobial peptide (HNP 1–3). The aim of this study is to analyze the correlation of HNP 1–3 secretion with CD63 expression on the surface of salivary neutrophils. This study constituted a cross‑sectional, analytical observational study. Saliva taken from preschoolchildren between the ages of 4–6 years who had been divided into two groups, i.e., early childhood caries group with decayed, extracted, filled teeth (def‑t) index >6 and caries free with def‑t = 0, was subjected to a HNP 1–3 secretion test using ELISA assay and an expression test for CD63 by means of a flow cytometry test. The results obtained were analyzed using independent t‑test and Pearson correlation (P < 0.05). The secretion of HNP 1–3 in the saliva of ECC was higher (172.6 ± 41.64) compared to that of caries‑free cases (140.39 ± 31.91), whereas the level of CD63 salivary expression in ECC was lower (2.32 ± 0.57) than in the presence of caries (2.67 ± 0.46). In ECC cases, saliva increases HNP 1–3 secretion but decreases CD63 expression on the surface of salivary neutrophils.

It is cleared that some probiotic strains inhibit biofilm formation of oral bacteria, but its mechanisms are not clearly understood yet. It is proposed that one of the mechanisms can be biosurfactant production, a structurally diverse group of surface‑active compounds synthesized by microorganisms. Hence, this study focused on the evaluation of the anti‑biofilm and antiadhesive activities of the L. rhamnosus derived‑biosurfactant against Streptococcus mutans and its effect on gtfB/C and ftf genes expression level. In this in vitro study Lactobacillus rhamnosus ATCC7469 overnight culture was used for biosurfactant production. The biosurfactant effect on the surface tension reduction was confirmed by drop collapse method. Chemical bonds in the biosurfactant were identified by Fourier transform infrared (FTIR). Anti‑biofilm and antiadhesive activities of the biosurfactant were determined on glass slides and in 96-well culture plates, respectively. The effect of the biosurfactant on gtfB/C and ftf genes expression level was also investigated after biofilm formation, total RNA extraction, and reverse transcription by quantitative real‑time reverse transcriptase polymerase chain reaction (PCR) assay (quantitative PCR). The data were assessed by one‑way analysis of variance in the Tukey–Kramer postdeviation test for all pairs. P < 0.05 was considered statistically significant. The FTIR results of biosurfactant showed that it was protein rich. It also showed anti‑biofilm formation activity on the glass slide and antiadhesive activity till 40% on microtiter plate wells. It also showed a significant reduction (P < 0.05) in gtfB/C and ftf genes expression level. L. rhamnosus‑derived biosurfactant exhibits a significant inhibitory effect on biofilm formation ability of S. mutans due to downregulation of biofilm formation associated genes, gtfB/C and ftf. L. rhamnosus‑derived biosurfactant with substantial antiadhesive activity is suitable candidates for use in new generations of microbial antiadhesive agents.

Until date, the proportion of nonclassic monocytes in type 2 diabetic mellitus patients with and without chronic periodontitis has not been evaluated based on glycemic control. The objective of this study was to compare the proportion of CD14+CD16++ monocytes in type 2 diabetic patients with and without chronic periodontitis. In this cross sectional study A total of sixty individuals with type 2 diabetes mellitus (n = 15/group) were recruited. Individuals were grouped based on glycosylated hemoglobin A (HbA 1c) values and the presence of chronic periodontitis; Group 1 (diabetes mellitus with good glycemic control), Group 2 (diabetes mellitus with poor glycemic control), Group 3 (diabetic mellitus with chronic periodontitis and good glycemic control), Group 4 (diabetic mellitus with chronic periodontitis and poor glycemic control). Fluorochrome‑conjugated monoclonal antibodies against CD14, CD16, and human leukocyte antigen–antigen D related was used to analyze the proportion of nonclassic monocytes by flow cytometry. One‑way ANOVA with Tukey’s post‑hoc test was used to assess the significant differences in monocyte subpopulations. The Pearson’s correlation test was used to assess the relationship between hemoglobin A1c values and percentage of nonclassical monocytes. In both the above statistical tools, the value of P < 0.05 is considered as significant level. Group 4 had the highest percentage of CD14+CD16++ monocytes 14.67% + 4.70%, followed by Group 3‑9.73% + 0.60%, Group 2‑9.32% + 2.03% and Group 1‑5.92% + 0.63% (P < 0.001). Further, a statistically significant positive correlation between HbA (1c) levels and the proportion of CD14+CD16++ monocytes was observed. In the present study, we observed type 2 diabetes mellitus patients with poor glycemic control and chronic periodontitis showed more than two‑fold increase in the proportion of nonclassic monocytes compared to type 2 diabetes mellitus patients with good glycemic control.

Stevioside is a natural herbal sweetener extracted from Stevia rebaudiana. An in vitro study has proved the antibacterial efficacy of 0.2% Stevia aqueous solution against Streptococcus mutans and Lactobacillus acidophilus, and the present study was conducted to clinically evaluate the efficacy of Stevia leaf extract and Stevia product on plaque pH, when compared with sucrose solution. A clinical trial was conducted among a sample of 22 undergraduate students who volunteered. After obtaining consent, students were instructed not to brush at night and not to use any mouth rinse during the course of the study. Baseline plaque pH was measured in situ using digital pH meter. Students were asked to rinse for 1 min with 0.2% aqueous solution of Stevia leaf extract and plaque pH was measured in situ at 4 time points (5, 10, 15, and 30 min) after each rinse. After a washout period of 2 days, 10% sucrose and 1% Stevia product solutions were similarly tested. Statistical analysis was performed using analysis of variance (ANOVA) test and repeated measures ANOVA. Tukey’s HSD test was used to obtain multiple comparisons. The level of significance was set to be at P < 0.05. At 5, 10, 15, and 30 min, a significant difference in mean plaque pH values was observed between three test solutions (P < 0.000). Post hoc Tukey’s HSD test showed that the difference in mean pH values between aqueous Stevia extract and sucrose and Stevia product and sucrose was highly significant (P < 0.000). Stevia leaf extract and commercially available Stevia product did not significantly affect plaque pH values, implying that two solutions are non‑fermentable and do not support bacterial survival.

This experimental study assessed reverse torque of indexed and nonindexed (NI) abutments in Morse Taper (MT) implants in a mechanical fatigue test.

In this experimental study It was used 37 implants MT and over them installed Pilar Flex abutments (4.8 mm × 6 mm × 1.5 mm). The groups were as follows: Group A used 19 MT implants with a NI Pilar Flex abutment loaded with 32 N/cm and Group B used 18 MT implants with an indexed (IN) Pilar Flex abutment loaded with 20 N/cm. The abutments were tested according to ISO standard 14801/2007. The specimens were installed at 30° from the axial axis and underwent a 133 N load, 4 Hz frequency, and 1,000,000 cycles. Once the test was completed, the reverse torque was provided by an electronic torque meter. Data were submitted to statistical analysis using the t‑test for independent samples and paired t‑test. The significance level was considered P < 0.05.

Results obtained showed that the indexed Pilar Flex abutment had a percentage of torque loss from the initial torque of 49% and the NI Pilar Flex abutment lost 14%. Paired Student’s t‑tests revealed that for both NI (P < 0.001) and indexed (P < 0.001) abutments, the counter torque values were significantly lower than those applied at the initial torque.

According on the methodology used, the NI Pilar Flex abutment was more effective regarding the reverse torque in single‑unit implant prostheses versus the indexed Pilar Flex abutment. A greater loosening in the indexed Pilar Flex abutment retaining screw was noted in the reverse torque test, and the Pilar Flex abutment failed to show good outcomes related to the cold welding effect.

Frequency analysis of metastasis in patients with oral squamous cell carcinoma (OSCC) helps to partly anticipate the upcoming chance of metastasis in the patients following primary diagnosis. This study was conducted to determine the evaluation of metastasis and 5‑year survival in OSCC. This was a retrospective, descriptive study. A total of 96 OSCC patients were studied. Demographic data and clinical view of lesion as well as histopathological grade of patients were recorded in previously prepared forms of pathology centers. These findings were then evaluated in relation to the 5‑year survival. The obtained data were fed into SPSS and analyzed by Chi‑square test, t‑test, one‑way ANOVA, and Scheffé test. A significant level of α = 0.05 was used. The 5‑year survival of patients was 41.7%. From among the patients, 44% were found to have local recurrence and 36% were reported to have distant metastasis. There was no significant association between the 5‑year survival rate and primary grade (P = 0.105). However, it revealed a significant relationship between the 5‑year survival rate and distant metastasis (P = 0. 001). This study showed that the 5‑year survival is dependent on the primary site of involvement, local recurrence, regional and distant metastasis, and mean age. However, gender (P = 0.89), grade (P = 0.105), and stage (P = 0.242) have no effect on the 5‑year survival of patients.

The diabetic subjects would have impaired oral stereognostic ability (OSA) compared with normal subjects due to diabetic neuropathy and microcirculatory disturbances. This study was conducted to compare the OSA between diabetic and nondiabetic complete denture wearers with and without denture. In this in vivo study the present comparative study comprised of seventy edentulous subjects (36 males and 34 females), aged from 35 to 84 rehabilitated with complete dentures (among them 35 were diabetic and 35 subjects were nondiabetic complete denture wearer). The OSA tests were conducted using acrylic test samples of 12 shaped forms, which were placed in patient’s mouth for a given period of time for identification and scored according to three‑point scale as OSA score and the identification time was also recorded. The data obtained were analyzed using Chi‑square test, t‑test, and Pearson’s correlation coefficient (P < 0.05). In this study, diabetic complete denture wearers got the mean OSA score of 12.43 ± 3.93 without dentures, which was lower than nondiabetic complete denture wearer group (14.82 ± 4.44). There was a significant difference (P = 0.020*) in the identification of test pieces. Within limitations of this study, diabetic complete denture wearers showed decreased OSA than nondiabetic subjects, particularly it was significant while not wearing dentures. Oral stereognosis may be used as one of the clinical aids in predicting patient’s performance to a prosthesis. Based on their response, we can educate the patient about the prognosis.

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. Central MEC (CMEC) is a rare tumor which affects women more than men and is more common in the mandible. Most cases are histologically classified as low‑grade tumor and radiographically appear as well‑defined unilocular or multilocular radiolucent lesion, although this tumor causes destruction and metastasis to other organs. In this article, we present a rare case of CMEC in a 47‑year‑old woman with unilocular radiolucent lesion of the mandible. Early and accurate diagnostic approach in all lesions with clinical/radiographical bland appearance is important, and all possibilities such as a malignant lesion should be considered.