Assessment of enamel surface roughness and hardness with metal and ceramic orthodontic brackets using different etching and adhesive systems: An in vitro study.

Background: This study aimed to evaluate enamel surface roughness and microhardness following the use of different bracket materials (metal or ceramic), etchants (total- and self-etchants), and adhesive systems (precoated or flash-free). Method: A total of 99 extracted human premolars were selected for the analysis. The surface roughness was first assessed (roughness control). One specimen from each subgroup was examined using a scanning electron microscope to illustrate the surface topography. Eighty-eight teeth were prepared using total- or self-etchants and bonded to precoated or flash-free adhesive metal or ceramic brackets. The remaining 11 specimens were not bonded to brackets (microhardness controls). The brackets were debonded after immersion in distilled water for 24 h. The specimens were again scanned for surface roughness and topography imaging. Finally, the microhardness was assessed using a micro-Vickers hardness test at a force of 200 g for 10 s. Result: An overall statistically significant increase in surface roughness and reduced surface microhardness were observed in all experimental groups when compared with those in the control groups. The etchant type was the only variable found to contribute to the measured surface properties, with increased roughness and reduced microhardness introduced by total-etching compared to those by self-etching. Conclusion: Orthodontic brackets introduced a significant increase in enamel surface roughness and reduce microhardness compared with untreated enamel, regardless of the bracket material, etchant type, and adhesive system. The etchant type was the only variable contributing to these changes, with total etching having a more pronounced effect.

Effect of topical fluoride application and diode laser-irradiation on white spot lesions of human enamel.

OBJECTIVES: This study aims to evaluate the effectiveness of topical fluoride application and diode laser-irradiation on the hardness of demineralized enamel and to evaluate the esthetic improvement of the white spot lesions (WSLs) using a visual analog scale (VAS). MATERIALS AND METHODS: Artificial WSLs (3x3 mm) were created on the enamel surface of 45 human third molars. The teeth were randomly assigned into three groups (n = 15): group A, fluoride only; group B, combined therapy of fluoride and diode laser; and group C, control. Vicker's hardness number (VHN) was measured at baseline, after demineralization and after treatment. To evaluate the esthetic improvement after treatment, 14 raters evaluated each group's photographs using a 100-millimeter VAS. A one-way ANOVA or Brown-Forsythe and Games-Howell post hoc procedure were performed for statistical analysis. The level of significance was set at α = 0.05 for all tests. RESULTS: Group A mean VHN was significantly higher than groups B and C, and group B was significantly higher than group C (P < 0.05). However, the mean VAS rating for the combined therapy group (B) was significantly higher than that for groups A and C (P < 0.05). CONCLUSION: Combination therapy significantly improved the esthetic appearance of WSLs compared to the fluoride only group. However, there was less enamel hardness versus treatment with fluoride only.

Evaluation of the airway space changes after extraction of four second premolars and orthodontic space closure in adult female patients with bimaxillary protrusion - A retrospective study.

BACKGROUND & OBJECTIVES: Previous studies have found that first premolar extractions during orthodontic treatment may alter the upper airway dimensions. The objective of this study is to investigate the effects of second premolar extraction during orthodontic treatment on the dimensions of the upper airway in a sample of female adults. METHODS: Twenty-nine female adult patients with ages between 18 and 30 years old and incisor bimaxillary protrusion were included in this study. They were treated with comprehensive orthodontic treatment which included the extraction of four second premolars. Pre and post cephalometric radiographs were analyzed using Dolphin imaging software for changes in tongue length and height, soft palate thickness and length, the superior, middle, and inferior airway space, and vertical airway length. Descriptive statistics were used to characterize measurements. Student's paired t-test was preformed to compare the pre- and post-test mean values of the dimensions. RESULTS: A significant increase in the vertical airway length was observed after the extraction of the second premolars (p = 0.02). The soft palate length showed a tendency towards an increase that did not reach statistical significance (p = 0.053). No other significant changes in the airway soft tissue measurements were observed. The proclination and protrusion of the upper and lower incisors were significantly decreased compared to pre-treatment measurements.Interpretation & conclusions.Orthodontic treatment involving the extraction of all four second premolars in females with bimaxillary protrusion increases the vertical airway length, which is the amount of distance between base of the tongue and posterior nasal spine. No other significant alterations in the upper airway measurements were observed.

Assessment of Knowledge about Dental Ergonomics among Dental Students of King Saud University, Riyadh, Kingdom of Saudi Arabia.

AIM: To assess the knowledge about dental ergonomics and work-related musculoskeletal disorders (WRMSDs) among dental students of King Saud University (KSU), Riyadh, Kingdom of Saudi Arabia, undergoing practical clinical training. MATERIALS AND METHODS: A self-designed questionnaire after pre-testing was distributed to 150 dental students of KSU undergoing clinical training, to collect data related to (a) basic knowledge about dental ergonomics; (b) any course/workshop about dental ergonomics attended; (c) basic knowledge about WRMSDs; (d) familiarity about preventive measures to decrease the risk of WRMSDs; and (e) knowledge about treatment options for WRMSDs. RESULTS: One hundred forty-two students (95%) returned the completed questionnaires, of them 54 (38%) were males and 88 (62%) were females. The main findings of the study are that only 30% of the students knew about dental ergonomics; 93% of students have not attended any course/workshop about dental ergonomics; about half the students knew about WRMSDs; 62% of the students did not know about preventive measures to decrease the risk of WRMSDs, and 80% of students did not have knowledge about treatment options for WRMSDs. In general, female students had a better understanding of dental ergonomics and WRMSDs than male students. CONCLUSION: The basic knowledge of the dental ergonomics among dental students at King Saud University, Riyadh, Kingdom of Saudi Arabia is not adequate. CLINICAL SIGNIFICANCE: There is a need for introducing dedicated theoretical and practical courses covering all aspects of dental ergonomics in the undergraduate curriculum of dental education.

Enamel demineralization around metal and ceramic brackets: an in vitro study.

AIM: To evaluate the degree of enamel demineralization of teeth bonded with ceramic and metal brackets. MATERIALS AND METHODS: In this cross-sectional experimental in vitro study, 60 extracted human premolar teeth were selected according to the experimental criteria. They were divided into three groups; 20 premolar teeth in each group. Teeth in group 1 were bonded with "ceramic brackets", and teeth in group 2 were bonded with "metal brackets", while teeth in group 3 served as the "control group" without any brackets. Teeth in all groups were then immersed in demineralization media, de-bonded, sectioned into three parts (proximal 1, middle, and proximal 2), and evaluated to determine the level of enamel demineralization under a Scanning Electron Microscope. RESULTS: On tooth level, the results show that the control group has significantly less enamel demineralization compared to the other two experimental groups, with mean values of 145.3 µm and 192.7 µm, respectively (P=0.000). The mean value of enamel demineralization in the metal group is 55.93 µm, compared to 72.55 µm in the ceramic group, which is significantly less (P≤0.05), while there is no difference between the control and metal group with regard to enamel demineralization. On section level, the control group has significantly less enamel demineralization in all three sections compared to the ceramic group, while a significant difference is found in one of the proximal sections when compared with the metal group. Moreover, the ceramic group has significantly higher enamel demineralization in the middle section compared to the metal group (73.54 µm, 46.5 µm, respectively) (P=0.000), while there is no statistical significant difference between the two experimental groups in proximal sections. CONCLUSION: In vitro, non-bonded teeth show least demineralization compared to the bonded teeth. Teeth bonded with ceramic brackets show significantly higher enamel demineralization compared to teeth bonded with metal brackets.

Enamel demineralization around two different orthodontic bracket adhesive systems: An in vivo study.

OBJECTIVE: To compare the enamel demineralization around the two precoated adhesive bracket systems, APC Flash-Free and APC PLUS (3M Unitek, Monrovia, CA, USA), in clinical settings. MATERIAL AND METHOD: This prospective experimental in-vivo study included 40 premolar teeth, which were planned for extraction due to orthodontic purposes. They were divided into two groups (Group A; n = 20 teeth were bonded with APC Flash Free ceramic brackets and group B; n = 20 teeth were bonded with APC Plus ceramic bracket). After four weeks, the teeth were extracted, sectioned, and examined under the Scanning Electron Microscope (SEM) to evaluate the amount of demineralization from the enamel surface to the deepest point. RESULTS: Findings revealed that the mean values of demineralization under SEM were significantly higher in APC Plus compared to APC Flash Free (149.95 µm vs. 112.96 µm, respectively) (P < 0.05). The difference between the two systems was mainly found in the middle part of the facial surfaces, while there were no differences between the two systems in the proximal parts. CONCLUSION: The enamel demineralization around APC Flash-Free adhesive bracket system was significantly less than that of APC plus Adhesive bracket system, which can be due to the absence of the caries promoting adhesive flash during tooth bonding using the flash free system.

The characteristics of dental occlusion in patients with moderate to severe obstructive sleep apnea in Saudi Arabia.

OBJECTIVES: To evaluate characteristics of dental occlusion among non-obese Saudi adult patients suffering from moderate to severe obstructive sleep apnea(OSA). METHODS: Following ethical approval, a cross-sectional study was conducted at Sleep Disorders Center, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia, between January and March 2017. Non-obese adult Saudi patients with moderate/severe OSA (apnea-hypopnea index more than 15) and without history of malocclusion or edentulism were included with an estimated sample size of 50. Demographic details and severity of OSA as diagnosed by polysomnography were recorded. Characteristics of dental occlusion, namely molar, canine and incisor relationship, overjet, overbite, crossbite and arch form were obtained through calibrated examiners (kappa 0.81). Descriptive statistical analysis and Chi-square test, with 95% significance level (p less than 0.05), were used to identify relationships between the severity of OSA and characteristics of dental occlusion. RESULTS: A total of 51 patients (31 males, 20 females; mean age 49.45±10.35 years), were enrolled in the study. Severity of OSA was moderate in 17 patients and severe in 34 patients. Severe form of OSA was more among males (64.7%) and in patients with Class-II division-1 incisor relationship (94.1%). Neither the demographic characteristics, nor characteristics of dental occlusion showed statistically significant relationship with the severity of OSA. CONCLUSION: The results of the present cross-sectional study indicate that the characteristics of dental occlusion are not related to the severity of OSA among non-obese adult Saudi patients.

Caries risk profiles in orthodontic patients: A 4-year follow-up study using the Cariogram model in governmental vs. private clinics.

OBJECTIVES: To (1) analyze caries-related factors and (2) evaluate caries risk using the Cariogram model for governmental and private orthodontic patients at de-bonding and 4 years after de-bonding. MATERIALS AND METHODS: Forty orthodontic patients with mean age of 26.4 years were recruited from a governmental (G) group (n = 20) and private (P) group (n = 20) and were examined at de-bonding (T1) and 4 years after de-bonding (T2). The examination included a questionnaire, plaque scoring, caries examination, bitewing radiographs, and assessment of salivary secretion rate, buffering capacity and cariogenic microorganisms. The data were entered into the Cariogram program to illustrate the caries risk profiles. RESULTS: The chance to avoid new cavities was higher in P-group compared to G-group at T1 (58% and 31%, respectively) (P < 0.01) and T2 (77% and 52%, respectively) (P < 0.001). Plaque index was significantly higher in G-group, and fluoride was used significantly more in P-group at T1 and T2 (P < 0.05). The chance to avoid new cavities was higher at T2 compared to T1 (64% and 44%, respectively) (P < 0.001). Saliva secretion rate and buffer capacity were significantly increased, and the plaque index was significantly decreased at T2 compared to T1 (P < 0.01). CONCLUSION: According to the Cariogram, orthodontic patients were less likely to avoid new cavities at de-bonding and 4 years after de-bonding in government clinics compared to private clinics, and the caries risk significantly decreased 4 years after orthodontic treatment for all patients, regardless of the location of treatment.

Diagnosing the severity of buccal caries lesions in orthodontic patients at de-bonding using digital photographs.

OBJECTIVE: The aims of this study were (1) to evaluate the severity of buccal caries lesions according to the International Caries Detection and Assessment System (ICDAS) criteria via scoring buccal caries lesions on digital photographs at the time of de-bonding and (2) to compare this method with clinical examination. MATERIALS AND METHODS: In total, 89 patients treated with upper and lower fixed appliances were clinically examined immediately after de-bonding by the first author and buccal caries were scored according to the ICDAS-II. Close-up digital photographs were taken of 245 teeth with different buccal caries lesion scores according to the ICDAS-II. Thirteen postgraduate orthodontics students independently scored the buccal caries lesions in the digital photographs using the modified clinical criteria (ICDAS-II). Intra- and inter-examiner reliabilities were evaluated by calculating the weighted kappa. To evaluate the validity of diagnosing the severity of buccal caries lesions using digital photographs compared to clinical examination, Spearman's correlation coefficient was calculated. RESULTS: Intra-examiner reliability and the reliability between each examiner and the clinical examination showed moderate-to-excellent agreement, with kappa values of 0.52-0.83. Scoring buccal caries lesions via clinical examinations and scoring via photographs were well correlated according to the modified ICDAS-II criteria (Spearman's correlation coefficient, 0.76). CONCLUSIONS: Thus, scoring buccal caries lesions on digital photographs according to ICDAS-II criteria is a reliable and valid method for assessing the severity of buccal caries lesions.

Diagnosing the severity of buccal caries lesions in governmental and private orthodontic patients at debonding, using the ICDAS-II and the DIAGNOdent Pen.

OBJECTIVES: To clinically evaluate the prevalence of buccal caries and white spot lesions (WSLs) at debonding in governmental and private orthodontic patients, using the International Caries Detection and Assessment System (ICDAS-II) and the DIAGNOdent Pen, and to study the correlation between the two methods. MATERIALS AND METHODS: A cross-sectional study was carried out on the nonextracted premolars and anterior teeth of 89 orthodontic patients. They were recruited into two groups based on the treatment center they attended: governmental group (G; n=45) and private group (P; n=44). Immediately after debonding, the examination of buccal caries and WSLs on premolars and anterior teeth was carried out using the ICDAS-II and the DIAGNOdent Pen. Cross-tabulation was applied to study the correlation between the ICDAS-II index and the DIAGNOdent Pen by calculating the Spearman correlation coefficient. RESULTS: The G group showed a significantly higher (P<.0001) prevalence of WSLs and/or buccal caries compared to that of the P group based on evaluation by the two methods. Based on ICDAS-II, 43% of the patients in the P group and 9% in the G group were free from any WSLs. In the G group, 22% of the patients had ≥16 LESIONS, whereas there were none for the P group. The Spearman correlation coefficient between the two methods was .71. CONCLUSIONS: The prevalence of caries and/or WSLs at debonding was significantly higher in the G group compared to the P group. The clinical index (ICDAS-II) showed a good correlation with the DIAGNOdent Pen.