Effect of Type of Resin Composite Material on Porosity, Interfacial Gaps and Microhardness of Small Class I Restorations.

AIM: This study aimed to compare the best restorative approach for the conservative class I cavity by comparing flowable and nanohybrid composites versus the placement technique regarding surface microhardness, porosity, and presence of interface gaps. MATERIALS AND METHODS: Forty human molars were divided into four groups (n = 10). Standardized class I cavities were prepared and restored using one of the following materials: Group I - Flowable composite placed by incremental technique; group II - Flowable composite placed in one increment; group III - Nanohybrid composite placed by incremental technique; and group IV - Nano-hybrid composite placed in one increment. After finishing and polishing, specimens were sectioned into two halves. One section was chosen randomly for the Vickers microhardness (HV) evaluation and the other section was used for the assessment of porosities and interfacial adaptation (IA). RESULTS: The surface microhardness range was 28.5-76.2 (p < 0.05), mean pulpal microhardness range was 27.6-74.4 (p < 0.05). Flowable composites had lower HV than conventional counterparts. The mean pulpal HV of all materials exceeded 80% of occlusal HV. Restorative approaches did not statistically differ in porosities. However, IA percentages were higher in flowable materials compared to nanocomposites. CONCLUSION: Flowable resin composite materials have lower microhardness than Nanohybrid composites. In small class I cavities, the number of porosities was similar between the different placement techniques and the interfacial gaps were highest in the flowable composites. CLINICAL SIGNIFICANCE: The use of nanohybrid resin composite to restore class I cavities will result in better hardness and less interfacial gaps compared to flowable composites.

Oral health knowledge, attitude and practice among adolescents in Kuwait.

OBJECTIVES: Adequate knowledge about oral health at a young age is essential in establishing good oral health related behaviors and in developing a positive attitude towards oral health. This study aims to assess the oral health knowledge, attitude and practice of adolescent children aged 15-17 years in Kuwait. METHODS: This cross-sectional survey was conducted in 12 randomly selected public schools in Kuwait using a two-stage cluster sampling method. An Arabic questionnaire with 29 questions were distributed to the students from selected classes. The questionnaire was divided into four sections: the first section gathered information on the sociodemographic characteristics of the participants; the second section assessed the oral health knowledge of the respondents; the third section assessed the students' attitude towards professional dental care and the last section assessed the students' oral health behaviors and practice. Frequency distributions were obtained for each variable and the differences between genders were analyzed using chi-squared statistics and the mean difference in the knowledge and attitude scores were analyzed using independent sample t-test. RESULTS: A total of 3,091 students aged 15-17 years (52.8% girls) participated in this study. The mean (SD) knowledge score of the respondents was 8.62 (2.53) and this was significantly higher for girls compared to boys (p<0.001). Significantly higher percentage of girls than boys knew the role of diet and oral hygiene in preventing caries (p<0.001). Knowledge about dental plaque was very limited in this population. Majority of the respondents believed that regular dental visits were essential (87.1%). The mean (SD) attitude score of the respondents was 3.30 (2.72) and this was significantly higher for girls compared to boys (p<0.001). Majority of the students used toothbrush and toothpaste to clean their teeth (60%). CONCLUSION: Significant gender differences were observed in the oral health knowledge and attitudes in this population. School based oral health promotion programs can be effective in promoting good oral health attitudes and practice among children.

The impact of ICDAS on occlusal caries treatment recommendations for high caries risk patients: an in vitro study.

BACKGROUND: The diagnostic criteria and tools used in caries lesion detection have been shown to affect the decision-making for caries treatment. Compared to other diagnostic criteria/classifications, ICDAS has been shown to provide a more accurate method for the detection of occlusal caries lesions. The influence of using ICDAS on caries treatment recommendations has received increasing attention in recent years. Therefore, the aim of this study was to assess the impact of ICDAS on dentists' occlusal caries lesions' treatment decisions for patients at high risk for caries. METHODS: Five dentists examined the occlusal surfaces of 270 extracted premolars and permanent molars. For a predetermined clinical scenario, the examiners were asked to indicate their treatment recommendations for each tooth. Four weeks later, all the examiners were trained and calibrated for the use of ICDAS. Then the investigators examined the same 270 teeth independently and indicated their treatment recommendations using the same clinical scenario. Histological validation was used to determine the caries lesions detection performance of the examiners using ICDAS and to assess the relationship between the presence of dentin caries and treatment recommendations for each examiner before and after ICDAS training. Specificity, sensitivity, area under the receiver operating characteristic curve (AUC), and Spearman's correlation coefficients were calculated. The Wilcoxon two-related sample rank test was used to test for differences between treatment recommendations. RESULTS: The strongest correlation for inter-examiner reproducibility was found between the ICDAS D2 cut-off point (ICDAS codes 3-6 as dentin caries) and histologic dentin caries. Treatment recommendations among different examiners before and after ICDAS training demonstrated a statistically significant increase in operative intervention and an increase in the percentage of overtreatment recommendations for two examiners. CONCLUSIONS: The impact of ICDAS on the examiners' caries lesion treatment recommendations varied among the dentists in this study. Treatment decision-making can be influenced by the caries lesion's detection and classification system used.

Impact of Magnifying Loupes on Interexaminer Agreement in the Detection of Noncavitated Occlusal Carious Lesions.

PURPOSE: This study aimed to assess the impact of using magnifying loupes on interexaminer agreement in the detection of noncavitated occlusal carious lesions. MATERIALS AND METHODS: A total of 155 permanent molars with no frank cavitation were selected for the study. Five examiners with different specialties and experience each examined the occlusal surfaces twice using International Caries Assessment and Detection System (ICDAS) criteria. The first examination used no magnification. The second examination, performed 4 weeks after the first, used 2.5X magnifying loupes. Later, the teeth were sectioned and inspected for caries using a stereomicroscope. The data were analysed using statistical analysis software to calculate intra-examiner reproducibility and interexaminer agreement as well as univariate marginal distribution and marginal homogeneity maximum Kappa (Kmax) statistics with and without the loupes. RESULTS: The Kmax scores for 4 of the 5 examiners showed bias compared to the histological results, with a greater likelihood of diagnosing a tooth as sound in the presence of caries (Kmax 0.26-0.73 and 0.19-0.65 with and without the loupes, respectively). For intra-examiner reproducibility, the linear weighted kappa ranged from (0.34-0.65) . Interexaminer agreement was poor both with and without the loupes. CONCLUSIONS: The use of magnifying loupes did not improve interexaminer agreement in ICDAS scores for noncavitated occlusal carious lesions.

Layered Base Plate Blocks and Operative Dentistry Skills.

AIM: Preclinical dental training is essential for the development of psychomotor skills necessary for clinical practice. The study aimed to investigate the impact of teaching with a layered base plate blocks on cavity preparations and students' self-perceived confidence, readiness, and ability. MATERIALS AND METHODS: A cross-sectional study recruited 52 dental students into two groups; one trained (test) with layered base plate and the other without (control). Students answered an eight-question survey to assess self-perceived confidence, readiness, and ability for performing cavity preparation at the start of their first preclinical operative dentistry course. Students prepared one molar tooth for a class I cavity and two for class II cavities. Preparations were assessed for different elements of depth and outline extension by two blinded examiners. RESULTS: Statistically significant differences were found between the median scores with respect to the preparation of class II cavities among students exposed to layered base plate (Mann-Whitney U-test, p < 0.05). There were no significant differences between the median scores awarded with respect to the preparation of class I cavity. A statistically significant difference was reported in self-perceived confidence among students who trained with the layered base plate (x2, p < 0.05). CONCLUSION: Training on the layered base plate blocks increased students' initial confidence level in performing cavity preparations, and improved the preparation skills in class II cavity. CLINICAL SIGNIFICANCE: This study explores the methods of enhancing motor skills taught in preclinical operative dentistry courses, especially in short academic programs.

Variables affecting the inter- and intra-examiner reliability of ICDAS for occlusal caries diagnosis in permanent molars.

OBJECTIVES: The aims of this study were to assess the validity and reproducibility of the International Caries Detection and Assessment System (ICDAS) in detecting occlusal caries in permanent molars and to investigate variables that can affect the reproducibility of ICDAS. METHODS: Five experienced, trained, and calibrated investigators examined the occlusal surfaces of 142 extracted permanent molars, ranging from sound to cavitated dentine caries. All visual examinations were conducted under standard conditions. Examinations were repeated after a period of 1 and 3 months from the initial examination. After all examinations were completed, teeth were sectioned and histologic validation was undertaken. Maximum kappa statistics were used to assess bias among examiners and linear weighted kappa was used to assess inter- and intra-examiners' reproducibility. Sensitivity, specificity, accuracy and area under the receiver operating characteristic curve were obtained at D3 threshold. RESULTS: Differences in the marginal homogeneity were observed for the general dentist. Kappa for intra-examiner reproducibility ranged between 0.66 and 0.81 and the inter-examiner reproducibility ranged between 0.42 and 0.75. ICDAS score of ≥3 presented the best Spearman's correlation coefficient (0.69) at Downer's histologic classification D3. Corresponding sensitivity and specificity values at that level were 0.73 and 0.95, respectively. While variables like the interval of time between teeth examinations did not affect the intra-examiner reproducibility, examiners' specialty influenced inter-examiner's reproducibility over time. CONCLUSIONS: ICDAS presented acceptable intra-examiners reproducibility in detecting occlusal caries over time. However, there was a clear effect for examiner's specialty and clinical experience on the inter-examiner's reproducibility of the ICDAS system at different time intervals.

Restorative treatment thresholds: factors influencing the treatment thresholds and modalities of general dentists in Kuwait.

OBJECTIVES: This study investigated the thresholds at which general dentists in Kuwait would restore approximal and occlusal carious lesions and examined the demographic characteristics of the dentists in relation to their decision making. SUBJECTS AND METHODS: The study population consisted of a random sample of 185 general dentists practicing in the Ministry of Health of Kuwait. A survey questionnaire was administered. The questionnaire presented different stages and locations of carious lesions; the participants were asked to identify the stage at which a restoration is required under different conditions, the preparation technique, and their choice of restorative material. RESULTS: For approximal carious lesions, 74 (40%) of the participants reported that they would restoratively intervene when the carious lesion reached the outer third of the dentin. A total of 91 (49.2%) reported the use of traditional class II restorations. For occlusal carious lesions, 128 (69.2%) said they would intervene when lesions reached the middle third of the dentin. 146 (78.9%) said they would remove the carious tissue only in their preparation. For both approximal and occlusal lesions, the participants preferred resin composite as the material for restoration. CONCLUSIONS: The respondents tended to delay restorative intervention until dentinal penetration of the caries. Resin restorative materials were used in conservatively prepared cavities. Participants chose a conservative approach for occlusal lesions but still believed in a traditional approach when it concerned approximal lesions. Experience, university dental education, and participation in continuous education courses were most significantly related to restorative treatment.

Factors relating to usage patterns of amalgam and resin composite for posterior restorations--a prospective analysis.

OBJECTIVES: This study prospectively analyzed the use of amalgam and resin composite posterior restorations placed by general dentists in relation to dentist, patient and cavity factors. METHODS: One thousand posterior restorations placed by a representative sample of general dentists working in the Ministry of Health (MOH), Kuwait, during routine clinical practice were included. Information about the restorations was recorded using a survey questionnaire. Descriptive statistics and multivariate logistic regression analysis were used to determine the factors associated with the use of amalgam versus tooth coloured restoratives. RESULTS: Dentists chose amalgam for 30.8% of the 1000 restorations. Dentists with longer work experience (>15 years) were more likely to choose amalgam (OR=2.61, 95% CI=1.06, 6.40). Younger dentists (≤30 years) were less likely to choose amalgam (OR=0. 45, 95% CI=0.26, 0.77). Amalgam was more likely to be chosen for patients with poor oral hygiene (OR=1.58, 95% CI=1.08, 2.32) and a higher number (≥4) of restorations (OR=1.44, 95% CI=1.07, 1.94) with large cavity sizes (OR=6.33, 95% CI=3.88, 10.32). Tooth-coloured restorations were more likely to be chosen for cavities of smaller sizes. CONCLUSIONS: The use of resin composite materials as the dominant choice among dentists in Kuwait reflects the trend worldwide. Nevertheless, clinicians still find a use for amalgam in posterior load-bearing teeth and in the high-caries risk population. CLINICAL SIGNIFICANCE: The findings give insight into factors influencing material usage under different clinical conditions and provides information about the perceived deficiencies or shortcomings of resin composite materials in a general dental practice setting. This information can be useful for identifying perceived barriers to the usage of newer restorative materials and finding ways to overcome them.

Caries experience among children with type 1 diabetes in Kuwait.

PURPOSE: The purpose of this study was to determine the association among type 1 diabetes mellitus (DM), caries experience, and salivary glucose in 12- to 15-year-olds in Kuwait. METHODS: A cross-sectional design was chosen involving 53 DM patients and 53 nondiabetic controls, group-matched by age and sex to the experimental group. The DM patients comprised 2 groups: (1) 14 controlled DM children (glycated haemoglobin, HbA1c=<8); and (2) 39 children with uncontrolled DM (HbA1c>8). The children's caries experience, at the precavitation and cavitation diagnostic threshold, was measured. In addition, their frequency of sugar consumption, plaque index, salivary flow rate, buffering capacity, as well as mutans streptococci, lactobacilli, and yeast counts were recorded. RESULTS: The DM children had significantly higher caries experience both at precavitation and cavitation diagnostic thresholds, than the control group. Multiple logistic regression analysis showed age, frequency of sugar consumption, and resting salivary flow rate to be significantly associated with high caries experience among the diabetic children. CONCLUSION: Caries experience was significantly higher in children with type 1 diabetes than in nondiabetic controls.

Effect of C-factor and LED Curing Mode on Microleakage of Class V Resin Composite Restorations.

OBJECTIVES: To investigate the effects of cavity C-factor and LED curing mode on microleakage of class V resin composite restorations. METHODS: Eighty extracted human maxillary premolars were divided into four groups. In groups I and II, V-shaped class V cavities (C-factor ≈ 1.5) were prepared while box-shaped class V cavities (high C-factor ≈ 4) were prepared in groups III and IV. All the cavities were prepared on the vestibular surfaces of the teeth. All the cavities were prepared by one operator with specific dimensions. The same adhesive system (Excite) and the same restorative composite (Tetric Ceram) were used in all the groups. The restorations in groups I and III were cured with the fast curing mode of LED curing light, while the restorations in groups II and IV were cured with the soft-start mode of the same curing light. The samples were thermocycled, immersed in a 0.5% basic fuchsin solution for 24 hours, and sectioned. The degree of dye penetration was measured quantitatively and then qualitatively at both enamel and dentin/cementum margins. RESULTS: Quantitatively, there was no statistical difference in the degree of microleakage between the groups at the enamel margin (P>.05). At the dentin/cementum margin, group III showed significantly more dye penetration than the other groups (P<.001). Similarly, qualitative measurements of dye penetration showed that group III had higher microleakage at dentin/cementum margin than the remaining groups (I and III P<.001; II and III P<.01; III and IV P<.01). Paired sample statistics showed that microleakage at the dentin/cementum margin was not statistically different from enamel mi-croleakage (P>.05), except for group III (P<.000). CONCLUSIONS: Fast curing mode of LED curing light resulted in more microleakage at the gingival floor of class V cavities with high C-factor. There was no difference in dye penetration between enamel and dentin margins of the cavities except when the fast curing mode was used with high C-factor cavities. Both quantitative and qualitative measurements of microleakage gave the same results at both enamel and dentin margins.

Clinical evaluation of posterior resin composite restorations placed by dental students of Kuwait University.

OBJECTIVE: To investigate the survival rate over a 3-year period of posterior resin composite restorations placed by dental students of Kuwait University. MATERIALS AND METHODS: Posterior resin composite restorations placed by 5th-, 6th- and 7th-year dental students between 2004 and 2005 were evaluated. All patients with posterior composite restorations placed during this period of time were recalled. Of the 204 eligible patients, 139 attended the recall. 432 posterior resin composite restorations were evaluated clinically and radiographically according to the United States Public Health Service criteria. For each restoration, the survival time and/or reasons for failure were recorded. Descriptive statistics and logistic regression analysis were used to analyze the data at a statistically significant level of p < 0.05. RESULTS: At 3 years, the survival rate of the restorations was 95.1%, resulting in an annual failure rate of 1.7%. Recurrent caries was the most common cause of failure (71.4%). Oral hygiene and gender and age of the patient were the factors that affected the failure rate of the restoration (p < 0.05). Other factors such as tooth type and location, type of cavity, type of liner used and level of the student who performed the procedure did not affect the failure rate (p > 0.05). CONCLUSION: Dental students of Kuwait University were able to place resin composite restorations in posterior teeth with a low annual failure rate. Recurrent caries was the most common cause of failure of posterior resin composite restorations. Oral hygiene was the most important factor in determining the survival of resin composite restorations.

A randomized clinical trial of in-office dental bleaching with or without light activation.

AIM: The study aimed to evaluate the effect of four in-office dental bleaching methods on shade change, color stability, patient satisfaction and postoperative sensitivity. METHODS AND MATERIALS: Forty patients were randomly divided into four groups (n=10) according to the method of in-office bleaching used: Group A-35% hydrogen peroxide (HP); Group B-35% HP plus BriteSmile and a blue curing light; Group C-35% HP plus QuickSmile and an LED curing light; Group D-35% HP and a Zoom2 metal halide curing light. For all groups, there was only one session of bleaching with three 20-minute applications of bleaching gel. The shade was evaluated before bleaching, immediately after, and one month after treatment using a VITA Classical Shade Guide. RESULTS: Immediately after bleaching there was a significant difference in color change between the four groups, with Group B having the best results. At one month there was no difference between the four groups. Immediate postoperative sensitivity was the least in Group A and the highest for Group B. Patients in Group B were the most satisfied with the outcome of the bleaching procedure. CONCLUSIONS: In general, the use of different lights for activation of an in-office bleaching agent did not affect the long-term results. Tooth sensitivity was mild and transient in the study. Patients were satisfied with in-office bleaching. CLINICAL SIGNIFICANCE: Using light activation with in-office bleaching seems to increase the efficacy of treatment only for a short period of time.

Re-Treatment Decisions for Failed Posterior Restorations among Dentists in Kuwait.

OBJECTIVES: To compare re-treatment choices for MOD amalgam or resin composite restorations with or without cusp fracture among dentists in Kuwait. METHODS: A random sample of 158 dentists completed a questionnaire designed to obtain socio-demographic, educational and work-related information and their choices for re-treatment of four scenarios of failed restorations on lower first molars: 1. MOD amalgam restoration; 2. MOD composite restoration; 3. MOD amalgam restoration with cuspal fracture; 4. MOD composite restoration with cuspal fracture. Re-treatment options were: re-treating with amalgam; re-treating with composite; placing an onlay; or, placing a crown. For the purpose of analysis, responses were dichotomized into re-treatment with a direct or indirect restoration. RESULTS: For cases 1 and 2, most participants chose to re-treat with amalgam restoration and for cases 3 and 4, most chose to place an indirect restoration. In general, an increased tendency towards the indirect option was associated with increased age, being a male and being a specialist. Tendencies to place an indirect restoration did not differ between cases 1 and 2 (P=1.0) or cases 3 and 4 (P=0.317), although the tendency to do so was significantly greater in case 3 than 1 (P=0.000) and case 4 than 2 (P=0.000). CONCLUSIONS: The variation noted among dentists regarding their stated choices for re-treating failed posterior restorations appeared to be associated with gender, education and experience factors. A tendency towards indirect restorations was seen when the restoration is associated with a fractured cusp.

Three-dimensional finite element analysis of the effect of incomplete seating of cemented fixed dental prostheses.

This study investigated the stress distribution patterns of two finite element models of a stylized fixed dental prosthesis-cement-abutment tooth system, one with the prosthesis completely seated and the other manipulated to be incompletely seated. Maximum equivalent von Mises stress varied according to direction and location of load, with vertical loading of the pontic of the completely-seated FDP (2.9 MPa) and oblique loading of the premolar of the incompletely-seated FDP (80.8 MPa) producing the least and the highest values, respectively. Total deformation of the restored system showed variations, although different cements had minimal effect on stress and on deformation. Under the conditions studied, a fixed dental prosthesis that had not been verified as fully seated on its abutments prior to cementation, could, with repeated loading cycles, be predicted to suffer a greater risk of fatigue, and thus clinical failure.

Recurrent caries at crown margins: making a decision on treatment.

OBJECTIVE: To evaluate dentists' treatment choices for a crowned tooth with varying degrees of recurrent caries. MATERIALS AND METHODS: A total of 158 dentists participated in the study. A paper patient case (PPC) depicting a radiograph showing varying degrees of recurrent caries at the crown margin was used: PPC1 = small carious lesion away from crown margin; PPC2 = small carious lesion at crown margin; PPC3 = small carious lesion at crown margin extending onto the root, and PPC4 = large carious lesion at the margin; PPC5-PPC8 had the same carious conditions as PPC1-PPC4, respectively, but the teeth were non-vital. Participants were asked to indicate their choice of treatment from a list of options for each PPC. Crown removal tendency was computed after dichotomization of the responses for the different cases for each participant. Demographic information, educational background and practice characteristics were collected. Descriptive statistics, logistic regression analysis and paired-sample t test were used to analyse the data at a statistically significant level of p < 0.05. RESULTS: For PPC1 and PPC5, most of the participants recommended management without crown removal (p < 0.05). For PPC6, there was wide disagreement about management (p = 0.81). For all other PPCs, the majority of participants chose to remove the crown before making a treatment decision (p < 0.05). Logistic regression analysis showed that the size of the lesion, vitality of the tooth, participants' age as well as the undergraduate training background of dentists were factors that affected treatment decisions. CONCLUSION: The data showed a lack of agreement among dentists regarding the management of recurrent caries around crown margins. Size of the lesion, vitality of the tooth, educational training and experience appeared to be the main factors that affected their decisions.

Effect of LED curing modes on postoperative sensitivity after Class II resin composite restorations.

PURPOSE: The aim of this study was to compare postoperative sensitivity following placement of posterior composite restorations using the fast- or step-curing modes of an LED curing light. MATERIALS AND METHODS: Thirty patients participated, with each having two homologous contralateral posterior teeth with Class II carious lesions. One restoration was cured using the fast-curing mode of the LED curing light (Mini LED), and the contralateral restoration cured using the step mode of the same curing light. The patients were contacted after 2 and 7 days postoperatively and asked about the presence or absence of sensitivity on a scale from 0 to 3.0: no sensitivity, 1: slight sensitivity, 2: moderate sensitivity, and 3: severe sensitivity. If the patient experienced sensitivity at 7 days postoperatively, he/she was contacted again after 30 and 90 days. RESULTS: There was a statistically significant difference in postoperative sensitivity between the two curing modes at days 2 and 7 postoperatively (p < 0.05) but not at days 30 and 90 (p > 0.05). The intensity of sensitivity was also different between the two curing modes at days 2 and 7 postoperatively (p < 0.05) but not at days 30 and 90 (p > 0.05). CONCLUSION: The step mode of the LED curing light reduced the incidence and severity of postoperative sensitivity following placement of posterior composite restorations compared to the fast mode of the same curing light.

Dental health attitudes and behaviour among dental students in Jordan.

OBJECTIVE: Examine and compare differences in oral health attitudes and behaviour among Jordanian dental students. BASIC RESEARCH DESIGN AND PARTICIPANTS: Cross-sectional study of 314 dental students was conducted to compare differences in oral health behaviour and attitudes among these students in different levels of academic education. SETTING: Jordan University of Science and Technology. METHODS: Subjects were surveyed using a modified version of the Hiroshima University Dental Behavior Inventory (HU-DBI) questionnaire (20 Items). Multivariate binary and polytomous logistic regression analyses were performed in order to study change of patterns of statements during preclinical and clinical, and year of study, respectively. RESULTS: The percentage of students claiming to brush their teeth twice daily or more often was four times higher amongst clinical students than amongst pre-clinical students.. The odds of visiting a dentist only in case of toothache was reduced by a factor of more than three among clinical year students (OR 0.30, 95% CI 0.15-0.61). Clinical year students rarely complained of bleeding gums after toothbrushing (OR 0.10, 95% CI 0.03-0.27). On the other hand, a number of items regarding use of dental floss and tooth paste, bad breath, colour and appearance of teeth, and cigarette smoking was similar between preclinical and clinical students. Evaluation of trends during dental studies employing polytomous multivariate logistic regression analysis revealed an abrupt change at the end of preclinical studies for items characterizing professional attitude. CONCLUSIONS: With advancement in dental school, dental student's oral health awareness and attitudes improved in some aspects. Preventive dentistry courses should be taught early in the dental curriculum of the pre-clinical years.

Smoking prevalence and its effect on dental health attitudes and behavior among dental students.

OBJECTIVE: To determine smoking prevalence and its effect on dental health attitudes and behavior among dental students in Jordan. SUBJECTS AND METHODS: A cross-sectional study of 314 dental students was conducted at Jordan University of Science and Technology. Subjects were surveyed using a modified version of the Hiroshima University Dental Behavior Inventory (HU-DBI) questionnaire. Multivariate logistic regression analyses were performed to study differences between male smokers and nonsmokers only. RESULTS: The response rate was 83.7%, with 48% males and 52% females. The prevalence of smoking was 17.2%. Smoking was more prevalent among male students (31%) than female (4.3%). For male students, the multivariate logistic regression analysis showed 6 items that were different between smokers and nonsmokers. Nonsmokers tended to brush their teeth more often than smokers (OR 8.67, 95% CI 1.66-45.25); claimed that they had never been professionally taught how to brush their teeth (OR 11.15, 95% CI 1.89-65.67); believed that they spend too much time brushing their teeth (OR 12.24, 95% CI 2.0-75.05); were more concerned about having bad breath (OR 41.86, 95% CI 3.44-58.75) and were more concerned about the color of their gums (OR 8.04, 95% CI 1.55-41.84). CONCLUSIONS: Smoking prevalence among male dental students in Jordan was high, 7 times greater than for females. Male smokers and nonsmokers had different attitudes and oral health behaviors as indicated by the study survey.

Effect of LED curing modes on cusp deflection and hardness of composite restorations.

This in vitro study measured cusp deflection associated with MOD resin composite restorations in maxillary premolars with different curing light modes. Soft-start polymerization may reduce cusp deflection by reducing polymerization shrinkage stress. Forty maxillary premolars were mounted in stone and slot MOD cavities were prepared. The teeth were randomized into four groups: Group A--cavities were etched, bonded and restored with two increments of Z-100 composite. Each increment was cured with an LED curing light (fast curing mode). Group B--similar to Group A except that the LED curing light with pulse curing mode was used. Group C--similar to Group A except that the LED curing light with stepped curing mode was used. Group D--a visible curing light was used for curing the composite. The distance between the indexed cusp tips was measured before the restorations were completed and five minutes after, 24 hours after and two weeks after completion of the restorations. The mean contraction of the cusps in microm at five minutes, 24 hours and two weeks, respectively, for each group was A: 25.4, 16.2 and 8.2, B: 6.4, 3.4 and 2.2, C: 11.6, 7.0 and 4.4, D: 33.0, 21.6 and 15.8. Group D resulted in the highest deflection, Group A was intermediate and Groups B and C were the lowest. Ten samples of the composite for each group with 2-mm thickness were prepared for the Vickers hardness test. No difference among the samples was found.