Non-thermal plasma treatment to enhance the adhesion between enamel surface and orthodontic bracket.

BACKGROUND: Adhesion strength of orthodontic attachments to enamel should be within optimal range to resist occlusal forces and to allow debonding without enamel damage. OBJECTIVE: The present study compared the effect of non-thermal plasma (NTP) and conventional surface treatment on the adhesion strength of orthodontic bracket to enamel. METHODS: A total of 100 premolar teeth were allocated into 5 groups according to the bonding procedure followed: Group 1 (Etch, prime and composite adhesive); Group 2 (Prime and composite adhesive); Group 3 (Glass ionomer cement); Group 4 (NTP, prime and composite adhesive) and Group 5 (NTP and glass ionomer cement). Ten specimens in each group were subjected to artificial aging and the remaining ten specimens served as baseline specimens. Adhesion strength values were recorded after debonding and bond failure types were scored. Water contact angles of the NTP treated and untreated enamel surface were measured. RESULTS: Group 1 specimen demonstrated highest bond strength at baseline (21.5 ± 3.01) and thermocycling (15.8 ± 2.87) and the least values were in Group 2 specimens at baseline (3.9 ± 1.01) and thermocycling (1.6 ± 0.7). Among the experimental (NTP) groups, Group 4 specimens exhibited high adhesion strength at baseline (10.2 ± 1.76) and after thermocycling (9.8 ± 2.15) compared to Group 5 specimens at baseline (10.1 ± 1.05) and thermocycling (6.5 ± 2.19). The water contact angle on untreated enamel surface was 53.1° ± 2.1° as compared to 1.4° ± 0.7° in treated surface. CONCLUSION: Non-thermal plasma (NTP) treatment in conjunction with composite adhesives demonstrated clinically acceptable adhesion strength and was well within the optimal range (7-14 MPa) for enamel bonding.

Prevalence of malocclusion among school children of Southern Saudi Arabia.

OBJECTIVE: To evaluate the status of occlusion among school children in city of Abha, Saudi Arabia. MATERIALS AND METHODS: The current study was based on the clinical examination of 1998 Saudis (mean age 14.13 ± 0.99 years) who were randomly selected by a multi-stage random sampling technique from the city of Abha. The occlusal parameters recorded in this study were molar and canine relationships, overbite, overjet, crowding, spacing, anterior open bite, anterior crossbite, posterior crossbite, and scissors bite using gloves, light source, mouth mirror, and ruler. RESULTS: Class I molar relationship was observed in 1219 (61%) of the total sample, while Class II and III molar relationships were observed in 326 (16.3%) and 154 (7.7%), respectively. Class I-III canine relationships were seen in 1255 (62.8%), 231 (11.6%), and 112 (5.6%) of the sample, respectively. Normal overbite was found in 1490 (74.6%) of cases, while 1515 (75.8%) had normal overjet. The most prevalent malocclusion trait was crowding (26.6%), followed by spacing (20.6%), increased overjet (19.5%), increased overbite (19.4%), posterior crossbite (8.5%), and anterior open bite (6.1%). CONCLUSIONS: Crowding was the highest occlusal trait in frequency followed by spacing, increased overjet, and increased overbite. Class I molar and canine relationships, normal overjet, and normal overbite were frequent findings among Saudi adolescents in Abha city.

Efficacy of Yttrium (III) Fluoride Nanoparticles in Orthodontic Bonding.

Our study evaluated the adhesion strength and antibacterial effect of a conventional orthodontic composite resin blended with yttrium fluoride (YF3) nanoparticles. Yttrium fluoride nanoparticles (NP) were added to the conventional orthodontic composite resin (Transbond XT) at concentrations of 1%, 2%, and 3% (w/w), and the blended composite resins were labeled as NP1, NP2, and NP3, respectively. A total of 60 extracted human premolars was randomly allocated to four groups of 15 samples (n = 15). Orthodontic brackets were bonded using the conventional (control) and experimental composite resins (NP1, NP2, and NP3). The adhesion strengths of the composite resins were determined using a universal testing machine. The debonding sites were assessed and scored using the adhesive remnant index (ARI). The antibacterial effect of YF3 nanoparticles against Streptococcus mutans was assessed by the viable cell counting method. For the same, 40 composite disc specimens were prepared using the control and experimental composite resins (n = 10). The data was analyzed by one-way ANOVA and Tukey's post hoc analysis. In all the tests, the significance level was determined to be 0.05. The highest adhesion strength values were found in the control group (11.61±0.23) and the lowest values were found in the NP3 group (10.49±0.17). A significant difference was observed between the control and experimental groups, NP2 and NP3 (P < 0.05). NP1 group showed insignificant (P = 0.388) adhesion strength values compared with the control group. There was no significant difference between the ARI scores of the conventional and experimental groups (P > 0.05). The highest colony forming units (CFU) were found in the control group (75.85±1.15) and the lowest CFU were found in the NP1 group (2.24±1.14). A significant difference between the mean CFU of the conventional and experimental composite groups was observed (P < 0.05). Despite higher antibacterial activity in the NP1 group compared with NP2 (P = 0.146) and NP3 (P = 0.117), the difference was not significant. Similarly, no significant difference was observed between NP2 and NP3 groups (P = 0.97). Our results suggested that yttrium fluoride nanoparticles, blended with a conventional resin at 1% concentration, demonstrated significant antibacterial effect and did not compromise adhesion strength.

Creep Behavior of Resin Composite Interface Between Orthodontic Brackets and Enamel.

PURPOSE: The present study investigated the creep of adhesive resin under constant loading at the orthodontic bracket/enamel interface with an orthodontic bracket-tooth model (shear creep) and three-point bending test (bending creep). MATERIALS AND METHODS: For the bracket-tooth model, sixty premolars were assigned to 4 groups (n = 15). Orthodontic brackets were bonded onto the enamel surface using four different bonding agents: conventional, homogeneous Transbond XT orthodontic composite (group 1/TBC); Transbond XT composite reinforced with photopolymerized glass-fiber-reinforced composite (FRC with bidirectional fibers) (group 2/TBE); Transbond XT reinforced with FRC of vertically oriented unidirectional fibers (group 3/TBV); and Transbond XT reinforced with FRC of horizontally oriented fibers (group 4/TBH). Load was applied at the bracket/tooth interface and from the bracket wire slot. In the three-point bending test, the creep and recovery of the rectangular interface materials were tested by a dynamic mechanical analyzer. The data obtained were statistically analyzed with ANOVA and a post-hoc test using SPSS v20 statistical software. RESULTS: The groups exhibited significant differences in strain % and time for bracket deflection at the interface (p < 0.05). The interface loading with unidirectional fibers (groups TBV and TBH) were statistically significantly different compared to the interface with bidirectional fibers and control group (groups TBE and TBC). The three-point test showed the least creep compliance (ie, creep deformation occurring at each time point [J]) with group TBC, followed by groups TBV and TBE. Group TBC showed the highest nanohardness and elastic modulus; the lowest values were seen in group TBE, reflecting differences in polymer matrix composition. CONCLUSION: The creep and time for debonding the bracket increased with incorporation of glass fibers at the interface between bracket and enamel.

The effect of fiber-reinforced composite versus band and loop space maintainers on oral Lactobacillus acidophilus and Streptococcus mutans levels in saliva.

BACKGROUND: Orthodontic bands have been shown to alter oral microbial flora that lead to convert caries-free patients to moderate or high caries risk individuals. AIM: This study aimed to evaluate the effect of conventional band and loop space maintainers versus fiber-reinforced composite (FRC) resin space maintainer on the salivary cariogenic microflora (Lactobacillus and Streptococcus mutans) in children over a period of 6 months. MATERIALS AND METHODS: The study sample was divided equally into two groups: Group A: 25 patients received FRC (INFIBRA®: Reinforcing ribbon, Bioloren, Italy) space maintainer and Group B: 25 patients received band and loop space maintainers. The saliva samples were collected from the patients before the insertion of the space maintainer and at 2 weeks, 3 months, and 6 months postinsertion. RESULTS AND CONCLUSION: The Lactobacillus acidophilus isolated was 1.7 colony-forming unit (CFU) (×106) and 1.8 CFU (×106) in Group A and Group B, respectively, prior to the insertion of space maintainers. There was no significant increase in L. acidophilus over the follow-up of 6 months in both the groups (P > 0.05). However, the Streptococcus mutans isolated before insertion in both Group A and Group B was 2.6 CFU (×106), which over a period of 6 months showed significant increase to 3.13 CFU (×106) in Group B (P < 0.05) and no increase was seen in Group A. S. mutans level increased considerably in patients with band and loop space maintainer over the follow-up of 6 months. No significant increase in the L. acidophilus count was observed over the same period in both the groups.

Biological aspects of orthodontic tooth movement: A review of literature.

This review of literature describes the cellular and molecular biology of orthodontic tooth movement, including various theories and effect of chemical mediators on tooth movement. The better understanding of the tooth movement mechanism will inspire the clinicians to design and implement effective appliances that will result in maximum benefits and minimum tissue damage to the patients. This paper also emphasizes the applied aspect of different medication and hormones, during orthodontic treatment, on the signaling molecules which produce bone remodeling.

Effects of Different Stain Removal Protocols on Bonding Orthodontic Brackets to Enamel.

AIM: To evaluate the effect of different stain removal protocols with or without topical fluoride application on the bond strength of orthodontic brackets to enamel. MATERIALS AND METHODS: Eighty extracted premolars were randomly assigned into four groups according to the stain removal protocol. The stain removal protocols were (1) using rubber cup with prophylaxis paste in (G1, n = 20), (2) air-abrasion with prophy-jet polishing system (G2, n = 20), (3) micro-abrasion with opalusture polishing paste (G3, n = 20), and (4) macro-abrasion with ultrafine diamond finishing tips (G4, n = 20). Ten teeth in each group (SG1, n = 10) had no topical fluoride treatment after stain removal protocol, while the rest (SG2, n = 10) were subjected to topical fluoride application. After bonding the orthodontic brackets, all specimens were thermocycled before testing their bracket-enamel bond strength. The debonded bracket and enamel surfaces of each specimen were also assessed to determine the adhesive remnant index (ARI) for each subgroup. RESULTS: Specimens in G2, G3, and G4 recorded lower shear bond strength as compared with G1 (p < 0.05). For all groups, specimens in SG2 demonstrated lower bond strength than their counterpart in SG1 (p < 0.05). No significant differences were detected between the ARIs of different subgroups (p > 0.05). CONCLUSION: Bonding orthodontic brackets is affected by the protocol of removing enamel stains. The use of the rubber cup with prophylaxis paste provided the highest bracket-enamel bond strength. Topical fluoride application usually complicates the bonding process of orthodontic brackets to cleaned enamel surfaces. CLINICAL SIGNIFICANCE: The results of the current study indicate higher bracket bond strength to enamel surfaces treated with different stain removal protocols than the clinically acceptable values (5.9-7.8 MPa). However, the more aggressive enamel pretreatment methods should not be considered unless the clinical situation necessitates such action. Postponing the topical fluoride application is advisable to follow the bracket bonding procedure. This action would prevent the negative effect of topical fluorides on bracket-enamel bond strength.

Effect of two-step and one-step surface conditioning of glass ceramic on adhesion strength of orthodontic bracket and effect of thermo-cycling on adhesion strength.

PURPOSE: The adhesion strength of orthodontic brackets bonded to dental glass ceramics was evaluated after ceramic surface was treated with two-step and one-step surface conditioning systems, and subjecting to thermo-cycling. MATERIALS AND METHOD: A total of forty specimens were fabricated from silica based glass ceramic (lithium disilicate) by duplicating the buccal surface of maxillary first premolar. The specimens were randomly assigned to two experimental groups (n = 20), group one specimens were treated with two-step surface conditioning system (IPS ceramic etching gel™ and Monobond plus™) and group two specimens were treated with one-step surface conditioning system (Monobond etch and prime™). The surface roughness of the specimens after treatment with two-step and one-step surface conditioning system was measured using non-contact surface profilometer. Ten randomly selected specimens from each group were subjected to thermo-cycling and the remaining ten served as baseline. The shear bond strength of the specimens was measured using universal material testing machine. The adhesive remnant index score was calculated, and the results of surface roughness and bond strength were tabulated and subjected to analysis of variance and post hoc tukey's test at a significance level of p < 0.05. RESULTS: The results of the study showed that the specimens treated with two-step conditioning system had higher surface roughness and bond strength than one-step conditioning system. The majority of the specimens treated with both two-step and one-step conditioned specimens showed adhesive failure after subjecting thermo-cycling. CONCLUSIONS: Traditional two-step conditioning provides better bond strength. The clinical importance of the study is that, the silane promoted adhesion significantly reduces on exposure to thermo-cycling.

An assessment of job satisfaction: A cross-sectional study among orthodontists of Saudi Arabia.

AIM OF THE STUDY: The main objective of the present study was to investigate the level of job satisfaction among professional orthodontists in relation to some significant intrinsic and extrinsic factors that generally affect their performance. MATERIALS AND METHODS: A cross-sectional study was conducted among orthodontists working in the Kingdom of Saudi Arabia using an online survey questionnaire through Survey Monkey. A total of 161 responses were received; among those, 57.8% of the respondents were Saudi and 42.2% were non-Saudi. RESULTS: On an overall satisfaction basis, a majority of orthodontists (80.7%) were satisfied with orthodontics as their profession irrespective of their gender. Only 4.4% showed dissatisfaction, whereas the remaining 14.9% were moderately satisfied with orthodontics as a profession. In-depth analysis revealed that a majority of the respondents (56.2%) showed reservations over having ample time for their family life. 52.8% of the respondents strongly agreed that they are assigned significant paperwork. Likewise, 66.5% of the orthodontists showed moderate to dissatisfaction over time adherence by the patients. CONCLUSION: The findings of the present investigations depicted a higher level of passion and commitment among the male and female respondents for the profession in spite of the fact that they do not have adequate time for their personal life. The working efficiency of orthodontists may be significantly enhanced by sparing them from too much paperwork and ensuring that their patients appear on time.

Anterior Open Bite Treated by Maxillary Posterior Teeth Intrusion Using Zygomatic Miniplates: A Case Report.

AIM: This case report aims to demonstrate the successful utilization of zygomatic miniplates in the treatment of an adult patient with anterior open bite (AOB). BACKGROUND: During treatment of anterior open bite, incisor extrusion may compromise facial esthetics in cases with long facial height and/or sufficient incisor exposure at rest and smile.The intrusion of posterior teeth has the advantage of correcting vertical dimension and maintaining proper incisors show. CASE DESCRIPTION: The patient, a 22-year-old boy, had an anterior open bite of 4.5 mm with increased lower facial height, bilateral posterior crossbite, and two different occlusal planes in the upper arch. Titanium miniplates were used to intrude maxillary posterior teeth with a transpalatal arch appliance to limit buccal tipping.The intrusive force was then applied through elastomeric chains placed bilaterally in the maxillary arch between the miniplate and posterior teeth.The anterior open bite was corrected within 7 months of intrusion with decreased lower facial heightand significant improvement in anteroposterior jaw relationship. CONCLUSION: This report emphasizes the significant role of facial appearance and smile. CLINICAL SIGNIFICANCE: Most of the non-surgical approaches are not suitable for open bite correction in cases with long facial height and/or sufficient incisor exposure at rest and smile because of their extrusive mechanics which compromise the facial and smile esthetics. The intrusion of posterior teeth using min iplates allowing a counterclockwise rotation of the mandible to correct anterior open bite without compromising facial esthetic and smile.

Dental students' perceptions of an online learning.

OBJECTIVES: To identify the readiness of students for online learning, to investigate their preference and perception, and to measure the quality of online tutorials. MATERIALS AND METHODS: A 14-statement questionnaire was administered to fourth year undergraduate dental students in male campus at King Saud University who completed preclinical orthodontic course. The students responded to each statement by using Likert scale. RESULTS: The results reveal a high agreement of students (27.8-31.5% agree and 38.9-50% strongly agree) on a possession of necessary computer skills and access to internet. 59.2% and 64.8% of the students replied that online flash lectures and procedural videos were helpful to their learning, respectively. With respect to students' learning preferences, few students preferred online flash lectures (31.5%) and procedural videos (17.1%). Most students (38.9% agree and 31.5% strongly agree) preferred a combination of traditional teaching methods and online learning. CONCLUSION: Overall, student attitudes were positive regarding online learning. The students viewed online learning helpful as a supplement to their learning rather than a replacement for traditional teaching methods.

Occlusal Status among 12-16 Year-Old School Children in Riyadh, Saudi Arabia.

BACKGROUND: Identifying occlusal status in a particular population will be valuable in planning the appropriate preventive and treatment programs. The purpose of this study was to assess the status of occlusion among school children in Riyadh, Saudi Arabia. MATERIALS AND METHODS: This study was conducted at Riyadh, Saudi Arabia from September 2012 to June 2013. A total of 1825 Saudis (1007 males and 818 females) of 12-16 years old were randomly selected from 20 schools in different areas of Riyadh city to determine the status of their occlusion. The examiners assessed molar and canine relationships, spacing and crowding, overjet, overbite, anterior and posterior cross bite. These occlusal parameters were examined by two experienced examiners using a mouth mirror, small light source and calibrated fiber ruler. RESULTS: About 60.11% of Saudis presented with Class I molar relationship while 7.12% and 10.13% of the subjects had Class II and III molar relationship, respectively. The most prevalent canine relationship was Class I (54.13%), followed by Class II (12.4%) and Class III (11.2). Normal overjet and overbite were observed in 76% and 67% of the sample, respectively. The prevalence of malocclusion traits were crowding (45.4%), Spacing (26.9%), excessive over jet (16.4%), posterior cross bite (8.9%), anterior open bite (8.4%) and excessive overbite (6.68%). No statistically significant differences were found between the genders about the prevalence of any occlusion traits (P > 0.05). CONCLUSION: Class I molar relationship, normal overbite, and normal overjet were dominant features among Saudis. Crowding was the most prevalent malocclusion trait, followed by spacing. These findings will help in understanding the occlusion status in order to plan for prevention and treatment of malocclusion in Riyadh city.

Anterior open bite treated with myofunctional therapy and palatal crib.

This case report demonstrates the treatment effects of palatal crib combined with the myofunctional therapy in a child with anterior open bite (AOB) due to thumb sucking and habitual anterior and low tongue position. The patient, an 11-year-old boy, had an anterior open bite and flared and spaced upper and lower incisors. Palatal cribs in conjunction with myofunctional therapy were used to discourage sucking habit and to adapt normal tongue position. Successful correction of the AOB with adequate overjet and overbite were achieved with total treatment time of 7 months. The importance of myofunctional therapy in adopting normal tongue position and in maintaining the stability of open bite correction is emphasized.

Is Tanaka-Johnston mixed dentition analysis an applicable method for a Saudi population?

OBJECTIVES: To test the applicability of the Tanaka and Johnston prediction method in a Saudi population. METHODS: The current study was conducted at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia from September 2013 to January 2014, on a sample of 409 pairs of orthodontic study models. The mesiodistal width of the mandibular permanent incisors, permanent canines, and permanent premolars were measured using an electronic digital caliper with an accuracy of 0.01mm. The predicted widths derived from the Tanaka and Johnston equation were compared with the actual measured widths. RESULTS: Gender differences were observed in the sum of the mesiodistal width of canine and premolars in both arches as indicated by t-test (p<0.001). The sum of the actual mesiodistal widths of canines and premolars were compared with the predicted widths derived from the Tanaka and Johnston equation and significant differences were found (p<0.001). The regression analysis indicated that the sum of the mesiodistal width of the mandibular permanent incisors is a good predictor for those of unerupted canines and premolars, with the correlation coefficients ranging from 0.51 to 0.61. Accordingly, 2 linear regression equations were developed for tooth width prediction for Saudi males and females. CONCLUSION: The Tanaka and Johnston prediction equation overestimated the sum of mesiodistal widths of permanent canines and premolars in Saudis. New regression equations were formulated for the prediction of tooth width in the Saudi population.

Perception of pain and discomfort from elastomeric separators in Saudi adolescents.

OBJECTIVE: To examine the patient's perception of pain and discomfort following the placement of elastomeric separators in Saudi adolescents. METHODS: The study was conducted on 38 adolescent patients who received fixed orthodontic treatment. The data was collected through the use of a self-administrated questionnaire that was distributed to the patients by one investigator in a non-clinical setting. The evaluation of pain started from the fourth hour after placement of elastomeric separators, and continued until the fifth day. RESULTS: The data showed that after 4 hours from separator placement, 94.7% of patients reported pain. There was a daily decrease in these percentages starting from the third day. The type of pain during the first 2 days was continuous, then continued to be intermittent pain. Most of the patients reported pain during eating and chewing, changed their food habit, and used analgesics. No statistical differences were observed between male and female patients in pain perception, type of pain, analgesic consumption, and influences on chewing and food consistency. CONCLUSION: The pain associated with orthodontic separation starts and peaks within 4-48 hours from separator placement, then starts to decline to reach the lowest level on fifth day.

Maximum mouth opening in saudi adolescents.

BACKGROUND: The aim of this study was to investigate the maximum mouth opening (MMO) in a representative sample of the Saudi adolescents. MATERIALS AND METHODS: A total of 1825 Saudi adolescents (1007 males and 818 females) aged 12-16 years were randomly selected. The subjects were asked to open their mouth maximally till no further opening was possible and then the distance from the incisal edge of the maxillary incisors to incisal edge of the mandibular incisors was recorded. All data were analyzed using SPSS program and simple descriptive statistics of MMO with regard to gender and age groups were reported. The Student's t-test and one-way analysis of variance were used to examine differences in mouth opening relative to gender and age groups. RESULTS: The mean maximal mouth opening for males was 43.5 ± 4.23 mm (range 29-59 mm). The mean maximal mouth opening for females was 35.5 ± 4.4 mm (range 20-45 mm). There was a significant difference between the mouth opening of males and females in all the age group (P = 0.000). The mouth opening, regardless of gender, increases significantly with age from the age of 12 years to the age of 14 years (P = 0.000), then remained unchanged till the age of 16 years. CONCLUSION: The mouth opening of males is significantly higher than that of females in all the age group. There was a significant increase in MMO with age up to the age of 14 years regardless of gender.