Comparison of therapeutic effect of mucoadhesive nano-triamcinolone gel and conventional triamcinolone gel on oral lichen planus Rastin Sadeghian, Bita Rohani, Zahra Golestannejad, Saeid Sadeghian, Shahla Mirzaee Dental Research Journal 2019 16(5):277-282 Background: Oral lichen planus (OLP) is a chronic disease without any definitive treatment. Local corticosteroids are often prescribed, but their efficacy has been questioned by many studies. The purpose of this study was to investigate the effect of nano-based triamcinolone acetonide gel (NT) and compare it with conventional triamcinolone gel (CT) on OLP. Materials and Methods: In this triple-blind randomized clinical trial study, 40 patients with Erosive OLP were divided into two groups receiving (CT) and (NT). The patients were requested to apply them four times a day for 2 weeks. The severity of pain was evaluated through visual analog scale, the size of lesions was measured with paper lace, and the appearance of lesions was examined adopting Thongprasom scale . Findings will be significant via independent t-test or Chi-square test with P < 0.05. Results: The severity of pain in NT group was 4.9 ± 0.7 cm before the treatment and 1.5 ± 0.9 after that, whereas in CT group, it was 4.9 ± 0.8 and 1.8 ± 0.9, respectively . The mean size of the lesions in NT group was 2.1 ± 1.1 cm before the treatment and 0.8 ± 1.1 afterward, whereas in CT group, was 2.2 ± 1.1 and 1.3 ± 1.1, respectively. The OLP appearance before and after the study in NT group was 4.5 ± 0.5 and 0.8 ± 0.6, respectively, whereas in CT group was 4.6 ± 0.5 and 0.9 ± 0.7 (P = 0.3). Among these variables, only Thongprasom scale on the 6th and 14th days had a significant reduction in NT group in comparison with CT group. Conclusion: NT has a better impact on OLP in comparison with CT, but this difference is not statistically significant.

Sponge amnion potential in post tooth extraction wound healing by interleukin-6 and bone morphogenetic protein-2 expression analysis: An animal study Dwi Wahyu Indrawati, Elly Munadziroh, Theresia Indah Budhy Sulisetyawati, Prasiddha Mahardhika El Fadhlallah Dental Research Journal 2019 16(5):283-288 Background: Wound tooth extraction is a mechanical injury that traumatizes adjacent tissue. Sponge amnion contains growth factors that can promote postextraction wound healing. Amnion membranes can be transformed into sponge form rendering it easier to use. The aim of this study is to analyze interleukin-6 (IL-6) and bone morphogenetic protein-2 (BMP-2) expression in postextraction wound healing on the 1st and 7th day after sponge amnion application. Materials and Methods: Twenty-eight Wistar rats were used in this experimental descriptive analytical study. Fourteen animals' first right anterior mandible tooth was extracted; then, the socket applied by sponge amnion and sutured (treatment group), while 14 others only sutured (as control group). The alveolar bone tissue of animal was observed 1st and 7th days after extraction and then was analyzed using immunohistostaining to identify the expression of IL-6 and BMP-2. Statistical analysis was performed using one-way ANOVA with the level of significance (P < 0.05). Results: IL-6 expression in the treatment group was significantly lower than the control group on the 1st and 7th days (P = 0.000). BMP-2 expression in the treatment group was significantly higher than the control group on the 1st and 7th days (P = 0.000). Conclusion: Sponge amnion can promote the healing process by increasing the expression of BMP-2 and decreasing IL-6 expression.

Dental education: Lecture versus flipped and spaced learning Shivani Kohli, Ashwin Kumar Sukumar, Cheah Tze Zhen, Andrew Sim Lim Yew, Alvena Ann Gomez Dental Research Journal 2019 16(5):289-297 Background: Even though there are diverse varieties of teaching methods to motivate and educate students, not many are used in dental institutions, where most rely only on traditional lectures. Hence, the objective of this study was to compare traditional lectures with newer teaching methods, specifically the flipped classroom and spaced learning method. Materials and Methods: In this prospective cohort study Students were randomized to one of the teaching methods, and their short-term (immediately after teaching) and long-term (i.e., 6 months later) knowledge retention was assessed through multiple choice questions, followed by students feedback which was obtained using Trierer Inventar zur Lehrevaluation questionnaire. P≤ 0.05 was considered statistically significant. Results: For short-term learning gains, spaced learning group (165.85) showed highest mean scores, followed by the traditional lecture group (163.70) and flipped classroom group (153.25).P value acquired through the Kruskal–Wallis ANOVA was statistically significant (0.003). For long-term knowledge retention, traditional lecture group has highest mean scores (147.50), followed by spaced learning group (146.90) and flipped classroom group (145.05) with no significant difference (P = 0.657). Conclusion: Spaced learning methodology was better than the traditional lecture method and the flipped classroom concerning knowledge gains when measured immediately after the application of learning method. For long-term knowledge retention, both the flipped classroom and spaced learning teaching methods were comparable to the traditional lecture method.

Comparison of bond strength of two porcelains and two base metal alloys in metal-ceramic restorations Asadollah Ahmadzadeh, Saghar Ghanavati Dental Research Journal 2019 16(5):298-303 Background: The purpose of this study was to evaluate the bond strength between two porcelains (VITA VMK Master and VITA VM13) and two types of base metal alloys (Ceramill Sintron and Verabond). Materials and Methods: In an experimental study, 20 rectangular strips (25 mm × 4 mm × 0.5 mm) of each base metal alloy (Ceramill Sintron and Verabond) were fabricated according to the manufacturer's instructions. After sandblasting and polishing, the samples were placed in an ultrasonic device to remove surface contaminants. A surface of 8 mm × 4 mm × 1 mm of samples was veneered with Vita VM13 and VITA VMK Master. The samples were divided into four groups (n = 10 each group; VM13/Ceramill, VMK Master/Ceramill, VM13/Verabond, and VMK Master/Verabond), and bond strength was evaluated by three-point bending test with a universal testing machine. Two-way ANOVA was used for comparison in each group, post hoc Scheffe's test was used for analyzing data between groups, and the Kolmogorov–Smirnov test was used for the normality (P < 0.05). Results: The maximum bond strength was related to Verabond/VM13 (44.35 ± 7.9 MPa) and then the Ceramill Sintron/VM13 (39.33 ± 4.43 MPa), and the lowest was related to the Ceramill Sintron/VMK Master (29.75 ± 3.2 MPa). There was no significant difference between bond strength of VM13 with the two alloy groups (P > 0.05), and bond strength of VMK Master to Ceramill Sintron CAD/CAM alloy was less than the conventional Verabond alloy (P < 0.05); however, bond strength of all the groups was above the standard threshold (25 MPa). Conclusion: Based on the results of this study, the bond strength of the porcelain to Verabond was better, but the bond strength of the porcelain to Ceramill Sintron also was not less than the standard threshold; thus, this new CAD/CAM alloy can be an alternative to the conventional base metal alloys in the metal-ceramic restorations.

Electrochemical assessment of laser-treated titanium alloy used for dental applications at acidic pH condition (in vitro study) Dalia Ahmed Abd El Daym, Mostafa Esam Gheith, Nadia Ahmed Abbas, Laila Ahmed Rashed, Zeinab A Abd El Aziz Dental Research Journal 2019 16(5):304-309 Background: Titanium alloys are widely used in dental applications as they have good mechanical and biological properties. Implant failure is more likely to occur in inflammatory diseases related to acidic pH. The aim of the present study was to assess the effect of erbium chromium-doped yttrium-scandium-gallium-garnet 2780 nm laser surface treatment on the electrochemical behavior of titanium alloy (Ti-6Al-4V) at acidic pH. Materials and Methods: In this in vitro study, a total of 20 discs of titanium alloy (Ti-6Al-4V) were used. First group, ten discs were irradiated with Er, Cr: YSGG laser which was operating in a normal room atmosphere and temperature at power 2W for 20 s at a constant distance of 0.5–1 mm with the laser system. The second group, ten discs untreated. The electrochemical behavior for both groups was investigated in simulated body fluid at pH 5.20 for up to 864 h at 192, 360, 696, and 864 h intervals using potentiodynamic polarization test and electrochemical impedance spectroscopy to evaluate the corrosion resistance. Results: Laser-treated Ti-6Al-4V showed higher corrosion resistance at pH 5.20 compared to the untreated alloy. Immersion time affected the electrochemical behavior. Conclusion: Er, Cr: YSGG laser could improve the corrosion resistance of Ti–6Al–4V at acidic pH.

Remineralization potential of dentifrice containing nanohydroxyapatite on artificial carious lesions of enamel: A comparative in vitro study Nithin Manchery, Joseph John, Nagappan Nagappan, Gireesh Kumar Subbiah, Parvathy Premnath Dental Research Journal 2019 16(5):310-317 Background: A carious lesion is the accumulation of numerous episodes of demineralization and remineralization, rather than a unidirectional demineralization process. Tooth destruction can be arrested or reversed by the frequent delivery of fluoride or calcium/phosphorous ions to the tooth surface. Nanohydroxyapatite particle-containing dentifrices are the newer generation of products which claim to remineralize enamel lesions effectively. The aim of this study was to evaluate and compare the remineralization ability of dentifrices containing nanohydroxyapatite, NovaMin, and amine fluoride on artificial enamel caries. Materials and Methods: In this in vitro study, extracted sound premolars were placed in a demineralizing solution to produce deep artificial carious lesions. The teeth were then sectioned longitudinally and divided into three groups (n = 16 in each group): Group A (nanohydroxyapatite), Group B (NovaMin), and Group C (fluoride). The sections were then subjected to pH cycling for 7 days. Polarized light microscopy was utilized to record the depth of the lesions before and after treatment with the selected dentifrices. Changes in the mean lesion depth were statistically analyzed by one-way ANOVA and t-test. The level of significance was assessed at P < 0.05. Results: The lesion depth decreased significantly by 10.56% in Group A, 6.73% in Group B, and 9.58% in Group C (paired t-test, P < 0.001). When comparisons were made across the groups, no statistical significance was found between the Groups A, B, and C (ANOVA test, P > 0.05). Conclusion: All three dentifrices were found to be effective in remineralizing artificial carious lesions. Nanohydroxyapatite dentifrice produced significantly better results compared to fluoride- and NovaMin-containing dentifrices, instigating for its use in the management of early carious lesions.

Effect of heat treatment and addition of 4-META to silane on microtensile bond strength of IPS e.max CAD ceramic to resin cement Laleh Soleimani, Homayoon Alaghemand, Seyyed Mostafa Fatemi, Behnaz Esmaeili Dental Research Journal 2019 16(5):318-326 Background: Silane promotes bonding between ceramic and resin cement. Silane function could be improved by heat treatment and adding 4-Methacryloxyethyl trimellitate anhydride (4-META). The aim of this study was to assess the effect of heat treatment and adding 4-META to silanes on the microtensile bond strength of IPS e.max CAD ceramic and resin cement. Materials and Methods: In this in vitro study, 32 IPS e.max CAD blocks (6 mm × 6 mm × 4 mm) were randomly divided into 8 groups of 4. The ceramic surfaces were etched by 10% hydrofluoric (HF) for 20 s, and Clearfil Ceramic Primer Plus, Clearfil Porcelain Bond Activator (CPA) +4-META, CPA + Clearfil SE Bond (CPA + SE), and Bis-Silane with and without Oven drying at 100°C for 5 min were applied on the ceramic surfaces as silanes, and then, the ceramics were bonded to composite disks by dual-cured resin cements. Ultimately, a total of 120 sticks ( 1 mm × 1 mm × 8 mm) were subjected to microtensile bond strength test (15 sticks from each group) and the failure types were assessed by stereomicroscope at 40x. Data were analyzed by two-sided analysis of variance test and Student's t-test the P values were considered to be < 0.05. Results: The Bis Silane group (two bottles) showed maximum bond strength (P = 0.009). Heat treatment significantly reduced the bond strength in Bis Silane (P = 0.0001); but, in other groups, it did not show significant effect on the bond strength. Adding 4-META to CPA did not significantly affect the microtensile bond strength of IPS e.max CAD ceramic to resin cement, and there was no difference in mode of failure between groups. Conclusion: The effect of silane type was significant on the microtensile bond strength of the ceramic to resin cement. The effect of 4-META on the bond strength was not significant. The interaction between silane type and heat treatment on the bond strength of ceramic to resin cement was also significant.

Angiogenesis in odontogenic keratocyst and dentigerous cyst: Evaluation of JunB and VEGF expression Donia Sadri, Sareh Farhadi, Pegah Nourmohamadi Dental Research Journal 2019 16(5):327-332 Background: Nowadays, different clinical behaviors of odontogenic cysts, little information about their biological agents, importance of diagnosis, and early diagnosis of these lesions have encouraged the researchers to conduct new studies. JunB acts as a regulator of vascular endothelial growth factor (VEGF) protein production and affects vessel proliferation and tissue angiogenesis. Hence, this study was conducted to compare angiogenesis through VEGF and JunB expression in odontogenic keratocysts (OKCs) and dentigerous cysts (DCs). Materials and Methods: A total of 25 paraffin blocks of OKCs and 25 DCs were included in this experimental descriptive cross-sectional study, and immunohistochemical expression of VEGF and JunB was evaluated. Percentage and score of expression were recorded for each sample, and independent t-test, Mann–Whitney U, and Spearman statistical tests were run to analyze the data. The statistical significance level was set at <0.05. Results: From 50 studied samples, 39.6% belonged to women and 60.4% belonged to men, with mean age of 34.2 ± 1.7 years. The mean percentages of JunB expression were 52.88 ± 17.35 and 74.6 ± 18.55 for DC and OKC samples, respectively. This expression was significantly higher in OKC than DC, and it had significantly higher scores as well (P= P = 0.0001 and 0.00033, respectively). The means of VEGF were 20.2% ±11.86 and 52.6% ±19.98 in DC and OKC samples, respectively. The mean VEGF expression was significantly higher in OKC than DC (P = 0.045), and it had significantly higher scores, too (P = 0.000). Furthermore, there was a significant correlation between VEGF and JunB expression in the studied samples (rs = 0.3 and P= 0.005). Conclusion: Based on the results of this study, it seems evaluation of angiogenesis through JunB expression can be helpful in the prediction of more aggressive behavior in pathologic lesions such as OKC.

Isolation of Enterococcus faecalis in the saliva samples of patient candidates for liver transplantation Jannan Ghapanchi, Amir Emami, Fahimeh Rezazadeh, Hajar Shakibasefat, Neda Pirbonyeh Dental Research Journal 2019 16(5):333-337 Background: Liver transplantation has turn into a standard management for chronic liver failure (CLF), and the number of recipients increased during the last few years. Enterococci are progressively related to nosocomial and opportunistic infections. Oral cavity may act as a reservoir for this species, especially in cases with oral infection. Immunocompromised patients are prone to serious enterococci-related disease. This study investigated the prevalence of Enterococcus faecalis in the saliva samples of patient candidates for liver transplantation. Materials and Methods: In this cross-sectional study the saliva samples of 100 patient candidates for liver transplantation and 100 age- and sex-matched healthy control group were collected. Bacterial DNA was extracted from the samples and E. faecalis was detected using polymerase chain reaction test. Fisher's exact test and Mann–Whitney test were used to correlate the positive and negative cases with the disease. Statistically, a significant difference was considered when P < 0.05. Results: There was no significant difference between both groups for the presence of E. faecalis. This bacterium isolated from the saliva of two cases in the study group and only one healthy control. The higher rate of carious teeth were detected in the oral cavity of CLF cases than control group (P = 0.001). Conclusion: Patients with chronic liver diseases assessed in this research showed a higher incidence of poor oral health and caries compared with the healthy controls, but there was no statistical difference in the presence of E. faecalis in saliva samples of each group. Complete oral examination, dental treatment, and oral hygiene instruction are necessary for all these cases before liver transplantation.

Effectiveness of buccal pouch grafting in minimizing loss of alveolar dimension: A canine investigation Ehsan Birang, Douglas Deporter, Reza Birang, Meysam Mahabadi, Eshetu Atenafu, Mohammad Ketabi Dental Research Journal 2019 16(5):338-345 Background: The study's purpose was to study buccal pouch grafting (BPG) with xenograft, freeze-dried bone allograft (FDBA), or FDBA + decalcified FDBA (DFDBA) on alveolar ridge width preservation and overlying soft tissue thickness at dog premolar extraction sites. Materials and Methods: In this animal study, 4 dogs had their mandibular first premolar (P1) and distal roots of P2, P3, and P4 extracted (after endodontic treatment of the mesial roots) bilaterally. A small buccal pouch was created at each extraction socket and four treatments tested: nothing, xenograft, FDBA, or FDBA + DFDBA. Casts made pretreatment and at 1 and 3 months after treatment allowed measurements of buccolingual alveolar ridge width (BLRW), while overlying buccal soft tissue thicknesses were measured clinically. Data were assessed using analysis of variance to compare changes in soft tissue thickness and BLRW between times and treatments. Tukey–Kramer adjustment for multiple comparisons was applied for doing post hoc, pairwise comparisons. Results were considered significant if P < 0.05. Results: Control sites showed significant (P = 0.0067) decreases in soft tissue thickness over time while there was a trend for increased soft tissue thickness at all grafted sites. There were significant losses in BLRW over time for control (P = 0.0032) and FDBA groups (P = 0.015) with a trend for loss with FDBA + DFDBA. Pairwise comparison using Tukey–Kramer adjustment revealed significant increases in BLRW from T1 to T3 for the xenograft group relative to all the others. Conclusion: BPG using xenograft is effective in maintaining hard and soft tissue stability following tooth extraction.