Perception and Knowledge of Oral and Facial Piercings among Dental Students: Web-based Survey.

AIM: The aim of this web-based questionnaire was to survey dental students to obtain their perception and knowledge of oral and facial piercings. MATERIALS AND METHODS: The participants comprised 240 students enrolled in the dental school who were asked to complete 20 close-ended, yes/no, yes/no/do not know, and multiple responses questions. The questionnaire covers general information concerning oral/facial piercing, triggers why youths and early adults get it, probable complications, their appreciation of the possibility of related health conditions, and their knowledge and perception. The survey was distributed to the students by email. The results were tabulated and statistically analyzed. RESULTS: Dental first year (D1) and dental second year (D2) were substantially more likely to indicate that orofacial piercings as unacceptable and are less expected to have an orofacial piercing compared to D3 and D4 (p < 0.01). About 16.8% of the students reported previous orofacial piercings. There was a definite correlation between previous orofacial piercings and thinking that is appropriate in society (p < 0.05). Males were significantly more likely to have an orofacial piercing (p < 0.01). The Internet was reported as the most common source of information. The most popular cause for piercings is to be unique and different. CONCLUSIONS: Orofacial piercings are relatively frequently used by students in dental school and few students intend on getting one in the future. Knowledge of the hazards of orofacial piercing correlated with the requirement for parental approval. The majority of students think piercings are appropriate in society and know their complications and risks. CLINICAL SIGNIFICANCE: Orofacial piercing has been gaining popularity but its risks/complications may not be known by practitioners. There is a need for research to assist dental/medical practitioners in advising, educating, and safeguarding patients by evaluating of the perception and knowledge of students about orofacial piercings.

A new implicit high-order iterative scheme for the numerical simulation of the two-dimensional time fractional Cable equation.

In this article, we developed a new higher-order implicit finite difference iterative scheme (FDIS) for the solution of the two dimension (2-D) time fractional Cable equation (FCE). In the new proposed FDIS, the time fractional and space derivatives are discretized using the Caputo fractional derivative and fourth-order implicit scheme, respectively. Moreover, the proposed scheme theoretical analysis (convergence and stability) is also discussed using the Fourier analysis method. Finally, some numerical test problems are presented to show the effectiveness of the proposed method.

Surface Treatments on Repair Bond Strength of Aged Resin Composites.

Aims: The aim was to evaluate the effect of different surface treatments on the repair shear bond strength of aged resin composites. Materials and Methods: Forty cylindrical-shaped specimens were treated from each material: Tetric Evo Ceram, Neo Spectra, and Filtek Ultimate Universal Restorative and allocated into four groups according to the surface treatment planned to use: Group 1: diamond, Group 2: silica coating, Group 3: carbide burs, and Group 4: control group. Following the surface treatment, composites were repaired with flowable resins. The shear bond strength was tested using a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture mode was assessed under 50× magnification. The data were analyzed statistically using a two-way analysis of variance (ANOVA) test followed by a one-way ANOVA test. Multiple comparison procedures were performed using Tukey's test. The level of significance was set at P < 0.05. Results: The lowest mean value of the shear bond strength was for the Filtek Ultimate Universal Restorative in the control group, whereas the highest mean value was in the silica group. Silica and carbide groups had significantly higher mean values of the shear bond strength than diamond and control groups in Tetric EvoCeram and Filtek Ultimate Universal Restorative. In contrast, in Neo Spectra St HV, the carbide group had a higher mean value but was not statistically significant. Conclusion: Combinations of mechanical and chemical retentive systems enhance the shear bond strength of the repair composite to the aged composite. Among the different surface treatments employed in this study, silica and carbide groups show higher repair bond strength of new composite to aged composite.

Numerical Solution of Two-Dimensional Time Fractional Mobile/Immobile Equation Using Explicit Group Methods.

In this paper, we shall present the development of two explicit group schemes, namely, fractional explicit group (FEG) and modified fractional explicit group (MFEG) methods for solving the time fractional mobile/immobile equation in two space dimensions. The presented methods are formulated based on two Crank-Nicolson (C-N) finite difference schemes established at two different grid spacings. The stability and convergence of order O ( τ 2 - α + h 2 ) are rigorously proven using Fourier analysis. Several numerical experiments are conducted to verify the efficiency of the proposed methods. Meanwhile, numerical results show that the FEG and MFEG algorithms are able to reduce the computational times and iterations effectively while preserving good accuracy in comparison to the C-N finite difference method.

Incidental Radiographic Detection of a Foreign Body in the Nose of a Child.

Foreign bodies in the nasal cavity are common in children, possibly due to their curiosity to explore body openings. The purpose of this report was to describe a case of an undetected nasal foreign body in a 10-year-old girl who presented to a pediatric dentistry clinic for a routine dental examination. A foreign body in the nasal cavity was discovered during a panoramic radiographic examination. A prompt referral to the otorhinolaryngologist was critical to confirm the diagnosis and successfully remove the foreign body. This case report demonstrates that dentists can play a significant role in the diagnosis of foreign objects in children.

Comparison of Fracture Resistance of Primary Incisors Restored with Different Intracanal-Reinforcement Materials.

AIM: To evaluate the effects of placing short posts made of different restorative materials on the fracture resistance of root canals in primary incisors of primary teeth. MATERIALS AND METHODS: The root canals of 40 extracted primary incisors were prepared and filled with Vitapex and randomly divided into five groups of 8 each. In Groups 1-4, a post space was created and filled with different restorative materials (Tetric® N-Ceram Bulk Fill, AeliteFlo, Filtek Z250 XT, and GC Fuji II LC® capsule), while Group 5 was kept filled with Vitapex as a control. Fracture resistance was measured using a universal testing machine at a 0.5-mm/min crosshead speed. The results were statistically analyzed and compared. RESULTS: The highest fracture resistance was recorded for GC Fuji II LC capsules [439.82 N] and control [423.37 N], while the lowest fracture resistance was recorded for Tetric® N Ceram Bulk Fill (239.91 N). A multiple comparison test showed that the Tetric® N-Ceram Bulk Fill had a significantly lower average value than AeliteFlo (P = 0.030), as well as a significantly lower average value than GC Fuji II LC® capsule (P = 0.001), and a significantly lower average value than the control group (P = 0.002). Multiple comparison tests showed no significant difference between Tetric® N-Ceram Bulk Fill and Filtek Z250 XT (P = 0.39). CONCLUSION: The fracture resistance of primary incisor root canals differs according to the material used for the intracanal posts. Three-millimeter intracanal posts in the primary incisors showed the highest fracture resistance for the teeth restored with GC Fuji II LC capsules and the control.

Clinical Efficacy of Single Use of Three Different Mouthrinses on the Level of Streptococcus mutans in Saliva.

AIM AND OBJECTIVE: The aim of this cross-sectional population-based clinical study was to assess the effect of single use of three different mouthrinses on the level of salivary Streptococcus mutans of 8 to 10-year-old Saudi children. MATERIALS AND METHODS: Convenient samples of 52 Saudi children aged 8-10 years were randomly allocated into four groups of 13 each. Saliva samples were collected to assess the level of S. mutans at baseline before rinsing with the assigned mouthrinse or control. Three mouthrinses, Avalon Avohex, Listerine Miswak, and Optima Aloe Dent Mouthrinse, were randomly distributed to the children. Each participant was instructed to rinse for 2 minutes using 10 mL of the assigned mouthrinse. Saliva samples were collected after rinsing and colony forming unit (CFU) of S. mutans per mL of saliva was calculated. Statistical analysis was performed to compare S. mutans count at baselines and postintervention values of each experimental group and control using paired t-test and one-way ANOVA. All statistical analyses were set at a significance level of p < 0.05. RESULTS: All test groups showed a reduction in salivary S. mutans compared to that at baseline. Statistically significant reduction (p > 0.05) in bacterial count was seen in Avalon Avohex group. CONCLUSION: A single-time rinse of chlorhexidine extract mouthrinse for 2 minutes effectively reduced the number of S. mutans of 8 to 10-year-old Saudi children. CLINICAL SIGNIFICANCE: Rinsing with chlorhexidine extract mouthrinse should be considered as a potential method in prevention of dental caries in children.

Effect of Whitening Toothpastes and Brushing on Microhardness of Esthetic Restorative Materials.

OBJECTIVE: Whitening toothpastes are widely used. Hence, it is important to understand their effect on the surface properties of restorative materials. To evaluate the effect of three over-the-counter whitening toothpastes and toothbrushing simulation on microhardness of three restorative materials. STUDY DESIGN: Forty cylindrical (10×2mm) specimens were prepared from each restorative material and randomly assigned into four groups/10 each according to the whitening toothpastes used and distilled water (control). All specimens were measured for microhardness (Baseline-T1). The specimens were brushed with a soft brush using an in vitro tooth-brushing simulator with the assigned whitening toothpaste using the same setting for brushing cycles/load for all groups. Specimens were then measured for microhardness (T2) similar to baseline. RESULTS: The highest (mean±SD) microhardness after application of the whitening toothpastes and brushing was recorded for Intense White and Filtek Z250 XT (127.6±1.8), followed by Optic White and Fuji ll LC (73.9±0.9) and Optic White and Photac Fill (72.7±1.3). There was statistically significant difference for microhardness between pre- and post-application of the whitening toothpastes and brushing for all tested restorative materials (P=0.0001). The microhardness of Filtek Z250XT with 3D White post-application of the whitening toothpastes and brushing was lowest compared to other toothpastes and control (P=0.0001). CONCLUSION: Microhardness increased after application of the whitening toothpastes and toothbrushing simulation for all combination of tested restorative materials and whitening toothpastes. The microhardness of FIiltek Z250XT with 3D White post-application of the whitening toothpastes and brushing was lowest compared to other toothpastes and control.

Shear Bond Strength of a Resin Composite to Six Pulp Capping Materials Used in Primary Teeth.

AIM: The purpose of this in vitro study was to assess the shear bond strength (SBS) and bond failure types of a resin-composite to six pulp-capping materials used in primary teeth. STUDY DESIGN: Eight-disc specimens from each pulp-capping material (6 groups) to bond to Filtek™ Z350 XT Flowable using a standard PVC tube (2×2mm). All groups were prepared according to the instruction of the manufacturer. The SBS was measured with a crosshead speed of 0.5 mm/min using a universal testing machine. Failure mode evaluation was completed using Digital Microscope by two independent examiners. RESULTS: Urbical LC® showed the highest SBS (Mean±SD) followed by ProRoot® MTA and TheraCal LC® (35.422±2.910, 22.114±2.515, and 21.175±1.983) respectively. ANOVA showed significant differences between all groups (P=0.0001). Urbical LC® and Photac™ Fil QuickAplicap™ were statistically significant different from all other pulp-capping materials groups. ProRoot® MTA was statistically significant different than Biodentine® (P=0.0001) and Photac™ Fil (P=0.0001). The total number of bond failure was recorded for cohesive B failure/cohesive in the pulp-capping material (14) and adhesive failure (14). CONCLUSION: Most of the tested pulp-capping materials bonded to Filtek™ Z350 XT demonstrated clinically acceptable and high SBS. Urbical LC showed the highest SBS while Biodentine® showed the lowest SBS.

A Comparative Evaluation of the Antimicrobial Effects of Different Mouthrinses against Oral Pathogens: An In Vitro Study1.

AIM: To assess the antimicrobial effects of natural and semi-natural mouthrinses on isolates of Streptococcus mutans, Lactobacillus fermentum, and Lactobacillus casei obtained from the saliva samples and their reference strains. MATERIALS AND METHODS: Natural and semi-natural mouthrinses included in this study were herbal mix mouthrinse, cranberry mouthrinse, chlorhexidine digluconate mouthrinse, cranberry extract mixed with chlorhexidine digluconate mouthrinse, chlorhexidine digluconate mouthrinse with alcohol (positive control), and distilled water (negative control). The microbiological examination tests were minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition test for the saliva isolates of S. mutans, L. fermentum, and L. casei while zone of inhibition test only for their reference strains. RESULT: Compared with distilled water, herbal mix, cranberry, cranberry mixed with chlorhexidine, chlorhexidine with alcohol (+), and chlorhexidine mouthrinses were associated with a significant increase of the zone of inhibition 34.354, 34.255, 34.219, 10.801, and 9.386, respectively. Both MIC and MBC were significantly higher in the cranberry mixed with chlorhexidine than in chlorhexidine with alcohol. The MIC and MBC of mouthrinses were significantly lower in the S. mutans and L. fermentum than in L. casei. CONCLUSION: Herbal mix and cranberry mouthrinses could be effective natural alternative to chlorhexidine mouthrinse with or without alcohol in improving oral health. CLINICAL SIGNIFICANCE: Different mouthrinses proposed in this study showed antimicrobial effects against the tested oral pathogens, and possibly the tested mouthrinses will lead for future formulation of natural or semi-natural pharmaceutical mouthrinses.

Effect of Probiotic Mouthrinses on Surface Microhardness of Esthetic Restorative Materials.

AIM: To assess the influence of three probiotic mouthrinses on the microhardness of three esthetic materials used for teeth restorations. MATERIALS AND METHODS: Thirty specimens of each material: conventional glass ionomer cement (GIC), resin-modified glass ionomer, and resin composite were randomly assigned to three groups. Surface microhardness was measured at baseline. The specimens were immersed in probiotic mouthrinses, group I: (P2 probiotic power), group II: (Probioclean), and group III (BoKU natural). Microhardness was measured after 21 and 63 minutes of immersion which is comparable with 3 and 9 weeks of mouthrinse use every day, respectively. Measurements of microhardness were completed using Micro Vickers testing machine with a 200 g load applied for a duration of 15 seconds. RESULTS: The microhardness change of the three restorative materials reveled statistically significant differences in all mouthrinse groups (p = 0.001). BoKU natural mouthrinse decreased microhardness significantly in all restorative materials (p < 0.05). However, Probioclean mouthrinse was associated with an increase in microhardness in all restorative materials. The effect of P2 probiotic power mouthrinse varied depending on time cycles and the restorative material. The mean difference in mouthrinse groups of resin composite was highest in BoKU natural at immersion time of 63 minutes. While no mean difference was seen in P2 probiotic power group at immersion time of 21 minutes which had no effect on the microhardness of resin composite. CONCLUSION: Surface microhardness was affected by immersion in probiotic mouthrinses. The BoKU natural mouthrinse had the highest reduction, while resin composite showed the least change in surface microhardness. CLINICAL SIGNIFICANCE: There is lack of studies that investigated the effect of probiotics mouthrinses on the surface properties of restorative materials. This study showed evidence that some of the tested probiotic mouthrinses in this study decreased the microhardness of the tested tooth-colored restorative materials after immersion for 21 and 63 minutes which is equivalent to 3 and 9 weeks of everyday use.

Effectiveness of educational intervention of oral health for special needs on knowledge of dental students in Saudi Arabia.

BACKGROUND: It is critical to educate dental students on the essential aspects of oral care for persons with special health care needs (shcn) as they acquire more dental diseases and 80% not receiving routine dental care. OBJECTIVE/HYPOTHESIS: To evaluate awareness and knowledge of dental students concerning oral-health care for persons with shcn, and to assess the effectiveness of an educational intervention in improving their knowledge. METHODS: Students completed an evaluation in the form of pre-post questionnaires that were answered before and immediately after the 30- minute dvd educational intervention regarding the oral health care of persons with shcn. ancova test where used to adjust for the pre knowledge and dependent t-tests were used. RESULTS: The mean ±â€¯sd of pre-test scores of all students was 15.46 ±â€¯2.97, which increased to 18.09 ±â€¯3.37 on the post-test. the post knowledge scores by dental class (adjusted for the pre knowledge) showed weak-significate anacova f test p value was (p < 0.050) however there was weak significant difference between the combined five years when compared (p < 0.050). however multiple comparison test (scheffe test) showed weak significance between d2 and d3 (p < 0.067). in addition, there was weak significant difference between post scores for each year when compared (p < 0.05). CONCLUSIONS: The educational intervention was effective in providing all five levels of dental students with the basic instructive information needed to care for persons with shcn. about 62% of students from all five years rated their knowledge as being minimal and about 98% reported they would use the information provided in the educational intervention.

Comparative Evaluation of the Antimicrobial Effects of Different Mouthrinses against Streptococcus Mutans: An in Vitro Study.

Purpose: To assess the antimicrobial effects of different natural and semi-natural mouthrinses on isolates of S. mutans obtained from the saliva of Saudi children and reference strains of S mutans (ATCC 25175). Study design: Saliva samples were collected from 20 children. Natural and semi-natural mouthrinses included were herbal mix mouthrinse, cranberry mouthrinse, chlorhexidine digluconate mouthrinse, cranberry extract mixed with chlorhexidine digluconate mouthrinse, chlorhexidine digluconate mouthrinse with alcohol (positive control), and distilled water (negative control). The microbiological examination tests were minimal inhibitory concentration, minimal bactericidal concentration, and zone of inhibition for the saliva isolates of S. mutans while zone of inhibition test only for reference strain of S. mutans. Results: For reference strain in a comparison with the distilled water, the herbal mix, cranberry, cranberry mixed with chlorhexidine, chlorhexidine, and chlorhexidine with alcohol showed significantly increased zones of inhibition by 36.38, 36.25, 26.13, 17.75, and 12.38, respectively. For saliva isolates in a comparison with the distilled water, the herbal mix, cranberry, cranberry mixed with chlorhexidine, chlorhexidine, and chlorhexidine with alcohol showed significantly increased zones of inhibition by 38.00, 34.25, 22.94, 16.50, and 16.44, respectively. Chlorhexidine with alcohol showed significantly lower minimum inhibitory and bactericidal concentration than the other groups. Conclusions: Herbal mix and cranberry mouthrinses could be effective natural alternative to chlorhexidine mouthrinse with or without alcohol in affecting tested parameters.

Effect of Remineralizing Agents on Bond Strength of Resin-Composites to Primary Enamel.

Aim: The purpose of this in vitro investigation was to assess the effect of three remineralizing agents (Voco Remin Pro®, Uncle Harry's remineralization kit, Sunshine remineralization gel) on the shear bond strengths of two resin-composites (Tetric® N-Ceram and Filtek™ Z250 Universal Restorative) to enamel of primary molars. Study design: Ninety-six enamel specimens were prepared and randomly distributed to eight groups according to the control, remineralizing agents, and resin composite used. Shear bond strength was measured at a crosshead speed of 0.5 mm/min and the type of bond failure was recorded. Results: The highest shear bond strength (Mean+SD) in MPa was for Tetric® N-Ceram/control [21.06+1.68] while the lowest was for Filtek™ Z250/Sunshine remineralization gel [11.98+1.46]. Tukey HSD Post Hoc Tests showed significant difference between Tetric® N-Ceram/control and all other groups (p=0.0001) except Filtek™ Z250/control. In addition, there was significant difference between Filtek™ Z250/control and all other groups (p=0.0001) except Tetric® N-Ceram/control and Tetric® N-Ceram/Uncle Harry's remineralization kit. Mode of failure was cohesive (9.38%), adhesive (55.21%), and mixed (35.42%). Conclusions: The three tested remineralizing agents affect shear bond strength of the tested resin-composites to enamel of primary teeth. In general, shear bond strength values were acceptable. Mode of failure was mostly adhesive.

A Comparative Evaluation of Six Prophylaxis Pastes, Cups, and Brushes on the Gloss of Three Restorative Materials.

Purpose: To compare the effect of different combination of prophylaxis-polishing pastes and cups/brushes on the surface gloss of three restorative materials (Filtek Z350, Tetric N-Ceram, and Ionofil Plus AC). Methods: Ninety disk-shaped specimens were prepared from each material, thermocycled, and randomly allocated into nine groups with 10 specimens each. Specimens were measured at baseline for gloss. Then, prophylaxis polishing pastes and cups/brushes were used, according to the instructions of the manufacturers. The second time measurements for gloss were completed. Results: The mean change of gloss among the three materials was statistically significant (P<0.0001). The two-way interaction terms "material and brush," "material and paste," and "brush and paste" indicated a statistically significant difference in mean change of gloss (P<0.0001, P<0.0001, and P<0.0001, respectively). The three-way interaction terms "material and brush and paste" showed a statistically significant difference in mean change of gloss (P<0.0001). Conclusions: The maximum change in mean gloss was recorded for Filtek Z350 XT, nylon brush, and Spectra paste followed by Filtek Z350 XT, nylon brush, Qartz paste, and Filtek Z350 XT, nylon brush, and Nupro paste. The change in gloss from pretreatment to posttreatment was significant across the three materials, the three brushes, and the three pastes.

Analysis of Risk Factors of Pancreatic Injury during Elective Laparoscopic Splenectomy in Children.

INTRODUCTION: Laparoscopic splenectomy (LS) became the standard choice for splenectomy in children with benign hematological disease. There are few reports about pancreatic injury during LS. The purpose of this study is to spot on factors increasing the risk of pancreatic injury during LS in children. PATIENTS AND METHODS: A total of 140 children had LS for benign causes. Children were categorized into A and B groups. LigaSure™ was used to control pedicle in Group A, while endoscopic staplers were used in Group B. Preoperative levels of amylase, lipase, and lactate dehydrogenase (LDH) were obtained. The mean of pancreatic enzymes and LDH values was calculated on the 3 postoperative successive days. RESULTS: A total of 71 boys and 69 girls had LS. The mean splenic size was 13.50 cm in Group A and 12.51 cm in Group B. The mean operative time in Group A was 41.91 min and in Group B was 56.36 min. The mean level of amylase was 42.99 IU/ml in Group A and 75.70 IU/ml in Group B (P = 0.001). The mean level of lipase was 37 IU/ml in Group A and 76.66 IU/ml in Group B (P = 0.001). CONCLUSION: Pancreatic injury during LS is a rare complication usually presented on biochemical level. We believe that it is a hemostatic-dependent complication rather than splenic size or nature of disease.

Effects of fruit drinks on surface roughness of two esthetic restorative materials.

OBJECTIVES: Restorative materials may be exposed in the oral cavity to chemical agents found in beverages, which may lead to their biodegradation. The purpose of this in vitro study was to evaluate the effect of two fruit drinks commonly used by children on surface roughness of two esthetic restorative materials. MATERIALS AND METHODS: One resin composite (RC), one resin-modified glass ionomer (RMGI) and two fruit drinks (orange and cocktail) were used in this study. Specimens (n=20) of each material were fabricated against Mylar strip. Baseline measurements of surface roughness were recorded for each group using noncontact surface profilometer. Each specimen was placed in the tested fruit drinks for 24 hours and then surface roughness was recorded. RESULTS: The mean (±SD) surface roughness of RC before and after immersion in orange and cocktail were 0.04±0.02, 0.12±0.05, 0.06±0.03 and 0.11±0.06, respectively and for RMGI were 0.72±0.14, 0.60±0.19, 0.56±0.11, and 0.52±0.15. For RC there was significant difference between surface roughness (Sa) before and after immersion in orange and cocktail (P<0.05). For RMGI, there was significant difference between surface roughness before and after immersion in orange (P<0.05), but no significant difference before and after immersion in cocktail (P>0.05). CONCLUSIONS: The surface roughness of the RC and RMGI examined showed a significant change in the surface roughness after immersion for 24 hours in the tested fruit drinks.

Qualitative Evaluation of the Bracket-Adhesive-Enamel Junction of Metal Orthodontic Brackets: A Preliminary Report.

OBJECTIVES: The purpose of this in vitro investigation was to evaluate qualitatively the surface topography at the bracket-adhesive-enamel junction, bonded to the buccal and lingual surfaces of premolars with composite resin and resin-modified glass-ionomer orthodontic adhesives, using two methods of adhesive removal: a dental explorer and a micro brush. METHODS: Forty premolar surfaces were allocated to four groups of 10/ each, 20/buccal and 20/lingual surfaces. The brackets were bonded to the surface of the enamel and any extra adhesive was removed with a dental explorer or a micro brush. Specimens were evaluated and scored by two calibrated independent raters, at the bracketadhesive-enamel junction, for adhesive overlap on the bracket, the smoothness of the surface, as well as the presence of projections and depressions, using a digital microscope. The Fisher-exact statistical test was conducted to compare the different groups. RESULTS: Regardless of the method used to remove the adhe sives, all groups showed partial or complete overlap of the adhesive on the bracket. No statistical difference was found between the groups for adhesive overlap (P=1.0). However, resin-modified glass-ionomer was found to be statistically significantly (P<0.05) better than composite resin in both smoothness and the lack of projections or depressions, regardless of the instrument of removal. CONCLUSION: Removing excess adhesive with a dental explorer or a micro brush is not an ideal method for adhesive removal, as partial or complete overlap of the adhesive on the bracket existed in all groups. On the other hand, resin-modified glassionomer was a superior material to composite resin for better smoothness and surface topography at the bracket-adhesive-enamel junction.

Shear bond strength of new and rebonded orthodontic brackets to the enamel surfaces.

OBJECTIVES: The objective of this study was to compare the shear bond strength (SBS) of new and rebounded orthodontic brackets bonded to the buccal sound and cleaned enamel surfaces using two orthodontic adhesives: resin-modified glass-ionomer (RMGI) and resin-composite. MATERIALS AND METHODS: Forty premolars were randomly allocated into four groups, 10 teeth/group. New and rebonded brackets were bonded to sound and cleaned enamel surface, and then were subjected to thermocycling. The bond strength was determined using a universal testing machine at a crosshead speed of 1 mm/min. Remaining adhesives on enamel after bracket debonding was scored independently by two investigators who were not aware of the four different groups, using adhesive remnant index (ARI). RESULTS: There was a statistical significant difference in SBS of the four groups (P = 0.005). SBS values were significantly higher with cleaned enamel surfaces after adhesive removal compared to sound enamel. SBS was significantly higher for rebonded brackets, when compared with the new brackets. No significant difference was found between the two adhesives types. The level of agreement between the two raters was higher toward the classification of higher categories of ARI (scores 5 and 6) with agreement percentage 91.7% and 100%, respectively. There was more adhesive remained among resin-composite groups. CONCLUSIONS: The bond strength of debonded sandblasted stainless-steel brackets was higher than new brackets. Resin-composite and RMGI orthodontic adhesives used in this study exhibited sufficient SBS values for bonding brackets to sound and cleaned enamel and comparable to each other.

Retention and caries-preventive effect of glass ionomer and resin-based sealants: An 18-month-randomized clinical trial.

The objective of this study was to compare the retention and caries-preventive effect of glass ionomer (Fuji Triage) and resin-based (Clinpro) sealants among 6-9-year-old children. This split-mouth, randomized clinical trial covered 35 children/140 fully erupted permanent first molars. Evaluation was conducted by two independent examiners after 6, 12, and 18 months and the data were compared in relation to the children's caries risk and age groups. The Kaplan-Meier survival method and chi-square test were used for analysis. There were no statistically significant differences in the survival of partial and fully retained sealants or in the survival of caries-free pits and fissures between glass-ionomer and resin-based sealants. In terms of retention, both sealants performed better in the younger age group at the end of the study, and showed better caries prevention in moderate caries risk children. After 18 months, both sealants had comparable retention and caries-preventive effects in 6-9-year old children.