The effect of salbutamol sulphate inhalation (an anti-asthmatic medication) on the surfaces of orthodontic Archwires.

OBJECTIVES: This study aimed to compare the surface roughness and friction of different orthodontic archwires after exposure to salbutamol sulphate inhalation, an anti-asthmatic medication. METHODS: Orthodontic archwires (stainless-steel [StSt], nickel-titanium [NiTi], beta-titanium [ß-Ti], and copper-NiTi [Cu-NiTi]) were equally divided into two groups. The exposed groups were subjected to 20 mg salbutamol sulphate for 21 days and kept in artificial saliva. The control groups were only kept in artificial saliva. Surface changes were visualized using scanning electron microscopy (SEM). The average surface roughness (Ra) was evaluated using atomic force microscopy (AFM), and friction resistance forces were assessed using a universal testing machine. Statistical analyses were performed using t-tests and ANOVA followed by post hoc tests. RESULTS: Salbutamol sulphate did not change the surface roughness of StSt and NiTi archwires (p > .05). However, the change in the surfaces of ß-Ti and Cu-NiTi archwires was significant (p < .001). The frictional forces of exposed StSt, NiTi, and Cu-NiTi archwires did not change (p > .05). However, the frictional forces of ß-Ti archwires increased significantly after exposure to salbutamol sulphate (p = .021). Brushing with fluoride after exposure to salbutamol sulphate increased the frictional forces of ß-Ti only (p = .002). CONCLUSIONS: Salbutamol sulphate inhalation significantly affected the surface texture of ß-Ti and Cu-NiTi orthodontic archwires and increased the friction of ß-Ti archwires. These deteriorating effects were not detected on the surface of StSt and NiTi archwires. Therefore, we suggest that ß-Ti and copper titanium archwires should be used cautiously in individuals under salbutamol sulphate inhalation treatment.

Comparison of occlusal bite force distribution in subjects with different occlusal characteristics.

OBJECTIVE: To analyze bite force distribution in subjects with different occlusal characteristics. METHODS: This prospective study included 132 candidates (50 males, 82 females) seeking orthodontic treatment, who were divided into four groups based on Angle's classification of malocclusion. T-Scan® III Version 7.0 was used to record their relative distribution of bite forces, which were compared using gender, Angle's occlusal classification, overjet, overbite, space analysis, sagittal, and transverse skeletal relations variables. RESULTS: ANOVA revealed significant differences in posterior/anterior bite force ratios between sagittal dental and skeletal relationships, overjet, and overbite groups (p < 0.05). No significant difference was found between different space analysis and transverse relationship groups (p > 0.05) or between genders (p > 0.05). CONCLUSION: Subjects with Class III, decreased overjet and decreased overbite displayed higher bite force in posterior teeth compared to other groups. This feature must be considered when evaluating patients with dental and periodontal pathologies that might be affected by excessive tooth stress, especially in subjects with oral parafunctions and bruxism.

Effect of citric acid erosion on enamel and dentin and possible protection by a novel bioactive borate adhesive system.

OBJECTIVES: This study examined the ability of a borate adhesive to protect enamel/dentin surfaces from acidic erosion and its effect on the shear bond strength (SBS) of enamel/dentin to resin composite. MATERIALS AND METHODS: 180 human enamel/dentin specimens were utilized. Enamel buccal surfaces were etched with phosphoric-acid then divided into: (EBG) borate glass adhesive group; (ERS) resin-adhesive system group; (EF) fluoride gel 1.23% group, and enamel control (EC) group; followed by bonding to orthodontic-buttons. The dentin specimens were conditioned by EDTA (Ethylene-diamine-tetra-acetic acid) and divided into: (DBG) borate glass resin, (DRS) resin adhesive; (DDA) group had a dentin-desensitizing agent VivaSens (VivaDent, Liechtenstein) and (DC) control group. The treated enamel/dentin specimens had their SBS to composite. The enamel/dentin specimens were exposed to 1% citric acid (18 min). Enamel/dentin specimens were examined by (SEM/EDS) scanning-electron-microscope equipped with electron-dispersive-spectroscopy and (FTIR/ATR). Analysis-of-Variance (ANOVA) was used to compare the SBS and Wilcoxon-signed-rank test was used to compare the enamel/dentin areas protected by the applied agents before/after erosion (p = 0.05). RESULTS: There was no significance difference in SBS among all groups except for (DDA) group that showed significant decrease p < 0.05. (EBG) and (DBG) groups were the only groups significantly protected enamel and dentin from erosion p < 0.05. FTIR/ATR showed that erosion altered the chemical structure of (DRS), (DDA), and (DC) groups but did not affect the other enamel/dentin groups. Degree of conversion of the borate-adhesive system was acceptable. CONCLUSION: The Borate adhesive system released calcium and phosphate compounds that decreased the erosive activity of the citric acid resulting in protecting simulated dentin-hypersensitive areas and enamel from erosion without affecting the SBS to resin-composite. CLINICAL SIGNIFICANCE: A Borate adhesive system can be adopted as a therapeutic agent in a fully integrated program for protecting dentin-hypersensitive areas and in enamel next to orthodontic fixed appliances.

Characterization of a novel enamel sealer for bioactive remineralization of white spot lesions.

OBJECTIVES: 45S5 Bioglass is a bioactive glass capable of releasing ions that can interact with dental hard tissues. The current study aimed at examining the effectiveness of 45S5 Bioglass in remineralizing enamel white spot lesion (WSL) as well as its effect on the bond strength of orthodontic brackets bonded to demineralized enamel. MATERIALS AND METHODS: WSLs were induced in the buccal surfaces of 135 human extracted teeth by storage in acid solution pH 4.5 for four days. The specimens were then equally divided into three groups; Demineralized group, Bioglass group (BG), and control group (intact enamel). The groups were chemically analyzed using (FTIR/ATR) Fourier-transform infrared spectroscopy/attenuated total reflectance, (XRD) X-ray diffraction, and (SEM/EDS) scanning electron microscope equipped with electron-dispersive-spectroscopy. Moreover, 10 specimens from each group were tested using Transverse Micro Radiography (TMR) technique, and 15 specimens from each group were bonded with metal orthodontic brackets and tested for shear bond strength test (SBS). The data were analyzed statistically using One way ANOVA p < 0.05. RESULTS: TMR study showed that bioglass group samples recorded lesion depth of 70.19 ± 29.21 µm and Δ Z (mineral loss) 732.15 ± 210.16 vol% µm which was significantly lower than the demineralized specimens having lesion depth of 115.75 ± 19.98 µm and Δ Z (mineral loss) 3472.69 ± 738.38 vol%µm, moreover, bioglass specimens recorded 14.15 ± 2.35 Mpa which was significantly higher than demineralized specimens 6.82+1.83 Mpa but less than the control specimens 20.5 + 6.1 MPa (p < 0.05). FTIR/ATR, XRD, and SEM/EDS tests showed that bioglass paste formed a layer of brushite crystals onto the treated enamel surface. CONCLUSION: 45S5 bioglass paste may serve as an effective remineralizing agent for demineralized enamel.

Atypical extraction in Class I malocclusion: A case report.

The treatment of Angle Class I malocclusion by atypical extraction is rather challenging. The extraction of four first premolars often manages it. However, in cases of compromised and non-restorable teeth, the extraction decision may be altered, making the anchorage and the treatment mechanics more challenging. This article reports the clinical case of a 16-year-old patient from Sudan who presented with a chief complaint "My teeth are crooked and sticking out." He had Angle Class I malocclusion with a bimaxillary dentoalveolar protrusion. He had severe crowding in both arches and localized marginal gingivitis related to an ectopically erupted upper right canine (UR3) and lower right first premolar (LR4). The patient had a provisional restoration in the lower right first molar (LR6). Extraction of three first premolars and one first molar was the alternative of choice for this treatment, which restored function, providing improved periodontal health, achieved the desired facial esthetics, and allowed finishing with a stable and balanced occlusion. Management of angle class I malocclusion with atypical extraction patterns should be performed with careful mechanics and anchorage planning to obtain good results.

Occlusion time, occlusal balance and lateral occlusal scheme in subjects with various dental and skeletal characteristics: A prospective clinical study.

OBJECTIVES: To analyse occlusion time, occlusal balance and lateral occlusal scheme in subjects with various dental and skeletal characteristics. METHODS: A total of 132 subjects (50 males and 82 females) seeking orthodontic treatment were included in this prospective study. Using the T-Scan III version 7.0 (Tekscan Inc, South Boston, MA, USA), the occlusion time, occlusal balance and lateral occlusal schemes were recorded and compared with gender, Angle's occlusal classification, overjet, overbite, space analysis, skeletal and transverse relations. ANOVA, t test and contingency tables analyses were performed. Statistical significance was set at P < .05. RESULTS: Occlusion time was significantly shorter in subjects with balanced occlusion (0.18 seconds, P < .001), Class I normal occlusion (0.35 seconds, P = .028) and Class I skeletal profile (0.37 seconds, P = .002). Occlusion time was significantly longer in subjects with decreased overjet (0.60 seconds, P = .003). There were significant associations between the distribution of occlusal balance and Angles' classes of occlusion, skeletal relationship, overjet, overbite and space analysis (P < .05). Lateral occlusal schemes were only associated with Angle's classes of occlusion and skeletal relationship (P < .05). CONCLUSIONS: Patients with Class I occlusion showed the least occlusion time, the most balanced occlusion and a higher frequency of canine guidance. Nonetheless, potentially balanced occlusion and group function were highly prevalent in all groups; therefore, ideal occlusion must be considered an ideal to inspire and aim for, but cannot be considered an essential requirement of every dental treatment.

The efficacy of a bioglass (45S5) paste temporary filling used to remineralize enamel surfaces prior to bonding procedures.

OBJECTIVES: The efficacy of using a 45S5 Bioglass paste as a remineralizing temporary filling material was compared to fluoride gel (1.23% acidulated-phosphate-fluoride, Gelato Gel, NJ, USA) applied for 24 h and for 4 min and to a temporary filling material (Caviton; GC, Tokyo, Japan). METHODS: 66 extracted human premolars were used. All specimens were sectioned mesio-distally. All specimens were challenged by a demineralization solution (pH4.5) for 4 days. The specimens were divided into 4 groups: (Bioglass), (Fluoride 4-minutes), (Fluoride 24-Hours), and (Temp) (n = 33). 10 specimens were examined by TMR (Transversal Microradiography)to test remineralization capacity of each agent. 8 specimens were assigned to determine the acid resistance of a bonded resin-enamel interface after the various treatment methods. 15 samples were assigned to determine the effect of each agent on the shear bond strength of a single bottle self-etch adhesive system. One way ANOVA was used to compare the obtained results (p < 0.05). RESULTS: Specimens treated with 45S5 bioglass showed statistically significant reductions in (delta z) values when compared to the other three groups (p < 0.05). Treatment of demineralized enamel by fluoride prior to bonding significantly decreased shear bond strength values, however 45S5 bioglass treatment did not affect the shear bond strength of adhesive system to enamel (p < 0.05). The acid-resistance of the interface between resin-enamel was significantly improved when fluoride or bioglass were applied onto the enamel surface prior to demineralization. CONCLUSIONS: 45S5 bioglass paste has high potential to be used as a remineralizing temporary filling material.

Increasing the efficiency of CPP-ACP to remineralize enamel white spot lesions.

OBJECTIVES: To compare the remineralization efficacy of using the MI paste plus according to manufacturer's instructions to MI varnish and to using a modified method of MI-paste plus application. MATERIALS AND METHODS: 100 enamel specimens were obtained from the buccal and lingual surfaces of 50 extracted human non-caries third molars. All specimens were challenged by a buffered demineralization solution for 4 days, and were divided in 4 groups with 25 specimens in each group. 25 demineralized specimens had MI paste plus applied for 4 min and then wiped out (MI), 25 specimens had MI paste applied followed by application of SE-bonding agent (MI + Bond), 25 specimens had MI Varnish applied according to manufacturer instructions (MI Varnish) the rest of specimens served as controls (C). All specimens were stored for 7 days in artificial saliva. All specimens had their surface hardness (SH) measured by micro-hardness tester before/after the acidic challenge and after the treatment procedures. After the SH test all specimens were crosssectioned to obtain 100-150 micron thickness specimens to observe the lesion depth before/after treatment by the TMR (Transverse Micro Radiography) technique. RESULTS: TMR experiment showed that (MI + Bond) and (MI varnish) groups recorded significant decrease in lesion depth and mineral loss of the tested subsurface lesion p < 0.05. (MI + Bond) group scored the highest significant regain of surface micro hardness results p < 0.05. CONCLUSION: (MI varnish) and the modified application of MI paste are methods that can increase the efficacy of CPP-ACP in remineralizing the enamel surface lesions.

Dentoskeletal effects of the forsus™ fatigue resistance device in the treatment of class II malocclusion: A systematic review and meta-analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis is to quantitatively compare previous studies that evaluated skeletal and dentoalveolar effects of the Forsus™ Fatigue Resistance Device (FRD) in the treatment of Class II malocclusion with a matched untreated control group. MATERIALS AND METHODS: Four electronic searches PubMed, Web of Science, Cochrane Library, and Science Direct that were limited to articles on human studies comparing the effect of Forsus appliance with a matched control group in the treatment of Class II malocclusion from the year (2000-2017). An additional manual search was carried out by examining the references of the included articles, SEARCH terms included; Forsus and Class II malocclusion. The quality of the included studies was assessed using the modified methodological score for clinical trials. The data were analyzed using Michael Borenstein's Comprehensive Meta-Analysis Software (V3.3.070, Biostat, Inc., US). RESULTS: Seven studies were included comprising 273 participants (Forsus group = 142; control group = 131). The results indicated a statistical significant skeletal effect of the Forsus appliance on increasing the occlusal plane only (P < 0.001). The results also indicated a statistical significant (P < 0.001) dentoalveolar effects of the Forsus appliance on the following outcomes; protruding, proclining, and intruding lower incisors; retroclining upper incisors, distalizing and intruding upper molars, as well as reducing overjet and overbite. CONCLUSIONS: The Forsus™ showed positive effects on the maxillary incisors and first molars as well as overjet and overbite. However, multiple negative effects were reported on the occlusal plane and lower incisors that need to be considered when using such appliance in treating Class II malocclusion.

Effects of chlorhexidine (gel) application on bacterial levels and orthodontic brackets during orthodontic treatment.

The objectives of this study were to evaluate the effects of applying 0.50% chlorhexidine (CHX) gel using the dental drug delivery system (3DS) on salivary Streptococcus mutans (S. mutans) and on the surface topography of metal and ceramic orthodontic brackets. The study involved 20 orthodontic patients with high levels of salivary S. mutans. The patients were treated with professional mechanical tooth cleaning followed by application of 0.50% CHX using individual trays (3DS). Salivary S. mutans levels were repeatedly measured 1, 2, 4, and 8 weeks post-treatment. In vitro study utilized forty ceramic and metallic brackets that were immersed in 0.50% CHX gel for 10 min, whereas another untreated forty brackets served as controls. The frictional resistances of stainless steel wires to the brackets before and after CHX treatment were recorded using a universal testing machine. Scanning electron microscopy was used to compare changes in the surface topography of brackets. Statistical analyses were used to determine the effect of CHX on bacterial count and to evaluate the effect of CHX on frictional resistance. According to the results of this study, S. mutans levels were reduced significantly (P < 0.05). There were no significant changes in the frictional resistance and surface topography of brackets before or after application of CHX. (J Oral Sci 58, 35-42, 2016).

Calcitonin and vitamin D3 have high therapeutic potential for improving diabetic mandibular growth.

The goal of this study was to assess the effect of the intermittent combination of an antiresorptive agent (calcitonin) and an anabolic agent (vitamin D3) on treating the detrimental effects of Type 1 diabetes mellitus (DM) on mandibular bone formation and growth. Forty 3-week-old male Wistar rats were divided into four groups: the control group (normal rats), the control C+D group (normal rats injected with calcitonin and vitamin D3), the diabetic C+D group (diabetic rats injected with calcitonin and vitamin D3) and the diabetic group (uncontrolled diabetic rats). An experimental DM condition was induced in the male Wistar rats in the diabetic and diabetic C+D groups using a single dose of 60 mg·kg(-1) body weight of streptozotocin. Calcitonin and vitamin D3 were simultaneously injected in the rats of the control C+D and diabetic C+D groups. All rats were killed after 4 weeks, and the right mandibles were evaluated by micro-computed tomography and histomorphometric analysis. Diabetic rats showed a significant deterioration in bone quality and bone formation (diabetic group). By contrast, with the injection of calcitonin and vitamin D3, both bone parameters and bone formation significantly improved (diabetic C+D group) (P < 0.05). These findings suggest that these two hormones might potentially improve various bone properties.

Comparison of shear bond strength to clinically simulated debonding of orthodontic brackets: An in vitro study.

OBJECTIVES: To assess in vitro the quantitative and qualitative debonding behavior of the AEZ debonding plier, compared to shear debonding force, in debonding orthodontic metal brackets. MATERIALS AND METHODS: Thirty-two extracted premolars bonded with metal brackets were randomly divided into two equal groups according to the type of simulated debonding method; compressive bond strength (CBS) group using AEZ debonding plier (Ormco Corporation, USA) attached to the Instron machine, and shear bond strength (SBS) group using regular Instron attachments. All teeth were subjected to debonding forces, and debonding strength was assessed. The buccal surfaces were then examined, under a stereomicroscope, and adhesive remnants were scored using adhesive remnant index (ARI). Debonding strengths comparison was performed using the independent sample t-test. ARI score comparison was performed using the Mann-Whitney U-test. Correlation between debonding strength and ARI scores was performed using the Spearman correlation. RESULTS: There was no significant difference in mean debonding strength between the SBS (M = 6.17 ± 0.77 MPa) and CBS (M = 6.68 ± 1.67 MPa) groups (P > 0.05). The CBS group showed significantly less adhesive remnants than the SBS group (P < 0.05); 62.5% of CBS group had ARI score 1, whereas 68.8% of SBS group had ARI score 3. No significant correlation between ARI and debonding strength was found (P < 0.05). CONCLUSION: SBS was found to produce similar debonding strength to the AEZ debonding plier in vitro. However, the AEZ debonding plier resulted in less adhesive remnant which is of great advantage for reducing chair-time during cleanup after debonding brackets.

Evaluation of mini-implant sites in the posterior maxilla using traditional radiographs and cone-beam computed tomography.

OBJECTIVES: To evaluate the accuracy of using routine 2-dimensional (2D) radiographs (panoramic and periapical) when evaluating the position of orthodontic temporary anchorage devices (mini-implants) in the maxilla, and to compare the results to 3-dimensional cone-beam computed tomography (CBCT). METHODS: This cross-sectional study was conducted at King Abdulaziz University, Faculty of Dentistry, Jeddah, Kingdom of Saudi Arabia from February 2014 to January 2015. Panoramic and periapical radiographs were used to examine the position of mini-implants in relation to the adjacent roots. Rating of mini-implants position was performed by 82 dentists from different specialties, using 2D images according to the following criteria: 1) away from the root; 2) mini-implant tip appears touching the lamina dura; and 3) mini-implant overlays the lamina dura. The results were compared with CBCT findings. RESULTS: There was no difference between dentists from different specialties when rating the position of the mini-implants (Cronbach's alpha=0.956). The accuracy of the periapical images was 45.1%, while the panoramic images 33.6%. However, both panoramic and periapical radiographs were significantly inaccurate when assessing the mini-implant position when compared with the CBCT findings (p=0.0001). CONCLUSION: Three-dimensional CBCT technology allows better visualization of mini-implant placement. The use of CBCT when assessing the position of mini-implants is recommended.

Differences in dentofacial characteristics of Class I malocclusion between Saudi and Japanese adult females.

OBJECTIVES: The objective was to compare dentofacial characteristics of Class I malocclusion in Saudi and Japanese adult females. MATERIALS AND METHODS: Lateral cephalograms of 50 Saudi adult female and 50 Japanese adult female (18-35-year-old) were obtained. All patients were skeletal Class I, angle Class I malocclusion, arch length discrepancy (-10-10 mm), overjet (1-5 mm), overbite (1-5 mm), absence of congenital anomalies, or significant facial asymmetries or congenitally missing tooth other than the 3(rd) molar and absence of temporomandibular joint problems. Patient cephalograms were traced and digitized. 16 angular measurements and 13 linear measurements of facial form were used. RESULTS: A comparison of the vertical dimension showed that the Saudi females had a significantly larger gonial angle, a significantly larger facial angle and longer lower face height compared to the Japanese females. Dentally, Saudi females had more protruded incisors with increased distances of the posterior teeth to the palatal plane. For the soft tissue dimension, the Saudi subjects had a significantly more prominent nose, retruded lip and a more protruded chin compared with Japanese. CONCLUSIONS: There were significant differences in dentofacial morphology between Saudi and Japanese adult females. Both Asian countries have distinct cephalometric features, which should be considered as a reference in treating patients of varying ethnic backgrounds to optimize the final results.

The effect of diabetes mellitus on rat mandibular bone formation and microarchitecture.

The aim of this study was to assess the effect of type 1 diabetes mellitus (DM) on the structure of mandibular bone and on the changes of alveolar/jaw bone formation. Experimental DM was induced in 3-wk-old male Wistar rats by a single dose of 60 mg/kg body weight of streptozotocin. All rats were injected with calcein on days 21 and 28. The rats were killed when 8 wk of age. Bone structure was analyzed by bone histomorphometry, microcomputed tomography (micro-CT), and histological section. Histomorphometric analysis showed that the mineral apposition and the bone formation rates in most of the mandibular regions were significantly decreased in the DM group compared with the control group. Micro-CT analysis showed significant deterioration of the bone quality in rats with DM. For a histometric measure of bone resorption, the number of osteoclasts along the distal surface of the alveolar wall was counted. The number of osteoclasts was significantly lower in the rats with DM than in the controls. These findings suggest that uncontrolled DM decreases mandibular bone formation, reduces the rate of bone turnover in the alveolar wall surrounding the root, and affects the quality of bone structure resulting in retardation of its skeletal development.