Ali Alrahlah

How effective the problem-based learning (PBL) in dental education. A critical review.

The purpose of this critical review is to explore the research supporting the effectiveness of problem-based learning (PBL) as a teaching method in dental education. PBL was developed more than 40 years ago in reaction to the problems and limitations of traditional teaching approaches. Here, aspects of the PBL teaching approach are reviewed, and the reasons for the substantial effect of this approach on dental education are discussed. Evidence shows that students in PBL-based courses exhibit superior professional skills and effective learning compared with those instructed using traditional approaches.

Effect of Er,Cr:YSGG on bond strength and microleakage of dentin bonded to resin composite with different distance and irradiation time

BACKGROUND To explore the surface modification of dentin using Er,Cr:YSGG phototherapy and bonding system on the shear bond strength and microleakage scores at two different distances and times of laser irradiation. MATERIALS AND METHODS Ninety disease-free third molars were collected for the experiment. The four laser groups were divided on the basis of non-contact mode distance and time of irradiation: Group-I: Distance of 1 mm with duration of 60 s; Group-II: Distance of 1 mm with duration of 120 s; Group-III: Distance of 2 mm with duration of 60 s and; Group-IV: Distance of 2 mm with duration of 120 s. The surface for control group (Group-EB: Etch & bond group) was treated with etch and rinse bonding regime. Specimens from all the groups were assessed for shear bond strength and microleakage scores. Samples from all groups were immersed in 2% methylene blue for 24 h and assessed under a digital microscope for microleakage. RESULTS The lowest bond strength and microleakage was observed in the control group EB. The maximum bond strength score was observed in Group-IV with mean scores 23.41 ± 1.83, while the maximum microleakage scores were observed in Group-II and Group-IV with mean scores 1.0 ± 0.36 and 1.0 ± 0.11, respectively. The lowest bond strength and microleakage among laser groups was observed in Group-II and Group-III, respectively. However, specimens in laser groups showed comparable bond strength and microleakge scores (p > 0.05). For bond strength and microleakage values, analysis of variance showed significant difference among the study groups (p < 0.001). Using Tukey post hoc test, bond strength and microleakage of laser groups showed statistically significant values than EB group. CONCLUSION Use of phototherapy using Er,Cr:YSGG for dentin surface treatment has the potential for clinical application in comparison to conventional conditioning technique. Increasing the distance of laser application and time of irradiation has significant effect on the shear bond strength and microleakage scores of dentin bonded to resin composite. However, further in-vitro analysis should be undertaken in order to prove such findings.

Effectiveness of adjunctive antimicrobial photodynamic therapy in reducing peri-implant inflammatory response in individuals vaping electronic cigarettes: A randomized controlled clinical trial

BACKGROUND There are no studies that have assessed the effectiveness of antimicrobial photodynamic therapy (aPDT) in reducing peri-implant inflammatory response in individuals vaping electronic cigarettes (e-cigs). This study explored the effectiveness of aPDT as an adjunct to mechanical debridement (MD) in the treatment of peri-implant mucositis (p-iM) in individuals vaping e-cigs. METHODS Vaping individuals with p-iM were divided into 2 groups: (a) Group-I: receiving MD with aPDT (test group); and (b) Group-II: MD only (control group). Peri-implant inflammatory parameters including plaque index (PI), bleeding on probing (BoP), and pocket depth (PD) were assessed at baseline and 12-weeks follow-up. Inter- and intra-group comparisons were made using Mann-Whitney U test and Wilcoxon signed ranks test. P-value < 0.05 was considered significant. RESULTS Thirty-eight male patients (20 in Group-I and 18 in Group-II) were included. The mean age of vaping individuals in groups I and II were 33.6 ± 2.8 and 35.4 ± 2.1 years, respectively. Mean daily frequency of vaping e-cigs in groups I and II was 7.3 ± 0.9 and 5.9 ± 1.0 whereas mean duration of vaping e-cigs was 4.8 ± 1.5 and 4.1 ± 1.3 years respectively. There was no significant difference between groups at baseline. There was significant improvement in PI (p < 0.001) and PD (p < 0.001) at 12-weeks follow-up with respect to the baseline visit in both groups. There was a significant reduction in PI (p < 0.001) and PD (p < 0.001) for group-I as compared to group-II at follow-up. There was no statistically significant difference for BoP between groups at follow-up. CONCLUSION Antimicrobial PDT is more effective compared to MD alone in the treatment of p-iM in individuals vaping e-cigs. The findings of the present study should be considered preliminary and interpreted with caution. Further randomized clinical trials should be performed in order to obtain strong conclusions.

Efficacy of photodynamic therapy or low level laser therapy against steroid therapy in the treatment of erosive-atrophic oral lichen planus

BACKGROUND The efficacy of photodynamic therapy (PDT) or low level laser therapy (LLLT) in the treatment of oral lichen planus (OLP) is debatable. The aim of this study was to compare the effects of PDT, LLLT or topical corticosteroid application in the treatment of erosive-atrophic OLP. MATERIALS AND METHODS Forty-five adult patients with erosive-atrophic biopsy-proven OLP on the tongue or buccal mucosa (size ≤3 cm) were randomly divided into three groups. Group-1: patients receiving PDT topical application of 50 μl toluidine blue (1 mg/ml) with micropipette and after 10 min treated by laser irradiation using GaAlAs laser (630 nm, 10 mW/cm2, continuous wave, spot size: 1 cm2); Group-2: patients receiving LLLT using diode laser (630 nm, 10 mW, continuous wave, spot size: 1 cm2); and Group-3: patients receiving topical corticosteroid applications consisting of dexamethasone (0.5 mg in 5 ml water) mouthwash for 5 min. Demographic data, type, and severity of the lesions and pain were recorded before and after treatment and then at the 1 year follow-up. RESULTS There was a significant difference in sign score changes before and after the treatment in the PDT group (p = 0.03), LLLT group (p = 0.04) and in the control group (p = 0.02). There was a statistically significant difference between group-1 (p = 0.001) and group-2 (p = 0.001) against group-3 before and after treatment. Mean amount of improvement in pain was significantly greater in the control group in comparison with the PDT and LLLT groups (p < 0.001). The efficacy index of the PDT group improved significantly more than the LLLT (p = 0.001) and corticosteroid groups (p = 0.001). CONCLUSION Within the limits of the present RCT, it is indicated that PDT and LLLT are effective in the treatment of erosive-atrophic forms of OLP in adult patients. However, further comparative clinical trials are needed to obtain strong conclusions in this regard.

Influence of Er: Cr: YSGG laser on adhesive strength and microleakage of dentin bonded to resin composite. In-vitro study

BACKGROUND The aim of this study was to evaluate the surface treatment of dentin with phototherapy (ER-CR-YSGG laser) in the presence of different bonding systems on their shear bond strength and microleakage. MATERIALS AND METHODS Eighty intact human third molars were divided into two groups. Forty teeth were treated with conventional flat wheel diamond bur and the remaining forty were treated with Er Cr YSGG laser (phototherapy). The two groups i.e. treated with laser (l) and group treated with abrasive bur (NL) were further divided into two subgroups of twenty samples each. Subgroup 1 was surface treated with etch and rinse (ER) and other 20 remaining samples were treated with self- etch (SE) bonding regime. Specimens from all the groups were assessed for shear bond strength and microleakage scores. Ten samples from all groups were immersed in 2% methylene blue for 24 h and assessed under a digital microscope for microleakage. Data was assessed using analysis of variance and tukey multiple comparisons test. RESULTS The lowest bond strength was achieved in laser prepared phototherapy group bonded with self-etch (LSE-11.87 ± 1.21). The maximum bond strength score was observed in non-laser-etch and rinse group (NLER-23.66 ± 2.56). The highest mean microleakage was observed among laser bonded with self-etch (LSE) specimens (1.0 ± 0.13). The lowest microleakage scores were seen in group treated with non-phototherapy etch and rinse (NLER-0.4 ± 0.11) regime. CONCLUSION Use of etch and rinse dentin bonding regime in combination with ER-CR-YSGG phototherapy dentin treatment has the potential for clinical application in comparison to conventional conditioning technique.

Simultaneous Evaluation of Creep Deformation and Recovery of Bulk-Fill Dental Composites Immersed in Food-Simulating Liquids

The aim of this study is to compare the creep/recovery behavior of bulk-fill dental composites after storage in various food simulating organic solvents. For this purpose, five different resin-composites (four bulk-fills and one conventional) were used. A total of 20 rectangular specimens (14 mm × 3 mm × 0.7 mm) were prepared by filling the resin-composites in Teflon mold. All of the specimens for each material (n = 5) were divided into four groups namely dry (control), distilled water (DW), artificial saliva, and absolute ethanol. The specimens were subjected to three-point bending creep test during immersion directly. A constant load of 2 N was used for each specimen with loading and unloading time 2 h each. Results: SF2 and XF showed a lower creep strain % after immersion, ranging from 0.44 (dry) to 0.75 (saliva) and 0.43 (dry) to 0.80 (ethanol), respectively. TNC BF depicts the maximum creep strain % ranging from 1.24% (dry) to 2.87% (ethanol) followed by FBF ranging from 1.17 (dry) to 2.59 (ethanol). However, the conventional material (GR) showed lower creep strain after immersion ranging from 0.28 to 0.54. Moreover, SF2 resulted in the highest creep recovery in all of the composites groups, as well as conventional material. The other composite groups showed lower creep recovery as compared to the conventional material (GR). The creep strain % for all the bulk-fill composites materials were increased during immersion in the liquids. However, for the conventional material, the creep deformation is decreased after immersion. SF2 showed the highest percentage of creep recovery among the bulk-fill composites, followed by XF.

Influence of experimental staining on the color stability of indirect computer-aided design/computer-aided manufacturing dental provisional materials

Objective: This study presents a comparative analysis of the color stability of computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated provisional restorations with those of conventional restorations. Materials and Methods: Three different provisional restorative materials (Systemp C&B, 3M Protemp 4, and Telio CAD) were inspected for their color stability using four solutions (Pepsi, coffee, tea, and distilled water). All samples used were fabricated using A1 shade by following the manufacturers instructions. Color assessment was performed using CIELAB system and a colorimeter. After baseline color measurement, color assessments were done weekly after immersion in specified solutions. Triplicate readings were taken for every sample and the mean value of the color coordinates (L*), (a*), and (b*) were recorded at baseline, week 1, week 2, week 3, and week 4. The data within different groups were compared statistically using analysis of variance (α = 0.05). Results: Overall, the highest color stability was found in CAD/CAM material, followed by Protemp and SystempC&B. It was also observed that the maximum color variation was observed in case of coffee, followed by tea and Pepsi. Conclusions: CAD/CAM provisional material (Telio CAD) showed better color stability compared to conventional materials (Protemp 3M ESPE and SystempC&B Ivoclar Vivadent). CAD/CAM provisional materials are recommended for long-term temporization procedures. This is attributed to the prepolymerization, higher monomer conversion, and minimal preparation errors in CAD/CAM materials.

Periodontal parameters in prediabetes, type 2 diabetes mellitus, and non-diabetic patients

The aim of the present study was to compare the clinical and radiographic periodontal parameters in prediabetes, type 2 diabetes mellitus (T2DM), and non-diabetic patients. Forty-one patients with prediabetes (Group 1), 43 patients with T2DM (Group 2), and 41 controls (Group 3) were included. Demographic data were recorded using a questionnaire. Full-mouth clinical (plaque index [PI], bleeding on probing [BOP], probing depth [PD], clinical attachment loss [CAL], missing teeth [MT]) and radiographic (marginal bone loss [MBL]) parameters were measured on digital radiographs. In all groups, hemoglobin A1c (HbA1c) levels were also measured. P values less than 0.05 were considered statistically significant. The mean age and HbA1c levels of participants in Groups 1, 2, and 3 were 53.4±3.5, 60.1 ± 0.6, and 56.6 ± 2.5 years and 6.1%, 8.4%, and 4.8%, respectively. The mean duration of prediabetes and T2DM in patients from Groups 1 and 2 were 1.9 ± 0.3 and 3.1 ± 0.5 years, respectively. PI, BOP, PD, MT, CAL, and MBL were significantly higher in Groups 1 (p < 0.05) and 2 (p < 0.05) than in Group 3. There was no statistically significant difference in these parameters in Groups 1 and 2. Periodontal parameters were worse between prediabetes and T2DM patients compared with controls; however, these parameters were comparable between prediabetes and T2DM patients.

Bond strength of universal adhesives to air-abraded zirconia ceramics

The bond strength of universal adhesives to air-abraded zirconia ceramic was evaluated. Overall, 40 zirconia ceramic blocks with dimensions of 6 × 6 × 4 mm were cut from pre-sintered blanks. The sintered blocks were embedded in self-cured acrylic resin. The zirconia blocks were then randomly allocated to four groups (n = 10) in which different universal adhesives were used, except for the control group in which no universal adhesive was used. A silicon mold was used to build the resin cement. All specimens were stored in distilled water for 24 h at 37°C and mounted on a universal testing machine. They were then subjected to shear bond strength testing at a cross-speed of 0.5 mm/min until failure occurred. The failure modes were analyzed using a digital microscope at 50× magnification. Univariate one-way analysis of variance and Tukeys post-hoc test were used for statistical analysis. Compared with the control group, the groups with universal adhesives showed statistically significant differences (P < 0.05). In addition, there was no statistically significant difference in the bond strengths of the groups with universal adhesives (P > 0.05) . After 24 h of storage, the cementation bond to air-abraded zirconia ceramic was improved by the application of a universal adhesive.

Effect of self etching ceramic primer and universal adhesive on bond strength of lithium disilicate ceramic

Abstract The clinical success of ceramic restorations is affected by the ceramic bonding procedure. The objective of the study was to evaluate the effect of different surface treatments, including the use of self-etching ceramic primer (SECP), on resin cement-glass ceramic bond strength. Thirty lithium disilicate ceramic (LDC) rectangles (3 mm × 3 mm × 8 mm) were fabricated Specimens were randomly assigned into three experimental groups (n = 10) according to the surface treatment: Group 1-hydrofluoric acid [HF acid]+ silane + universal adhesive; Group 2-HF + universal adhesive; Group 3-SECP + universal adhesive. All specimens were stored in distilled water for 24 h at 37 °C and shear bond strength (SBS) was tested at a crosshead speed of 0.5 mm (Universal Testing machine-Instron). Failure modes were evaluated using a digital microscope for all specimens. Analysis of variance and the Tukey post hoc tests using SPSS (Version 22.0, IBM, New York, USA) were used to analyze data. The SBS of groups 1 (19.74 ± 1.28 MPa) and 3 (21.11 ± 2.07 MPa) were significant higher than group 2 (14.80 ± 1.94 MPa). The SBS values for specimens in groups 1 (19.74 ± 1.28 MPa) and 3 (21.11 ± 2.07 MPa) were comparable. Adhesive, mixed and cohesive failure modes were observed and mixed failure was the most common in all groups. Therefore, the use of SECP and universal adhesive is recommended as an alternative to the use of HF acid in combination with ceramic primer while bonding to LDC.