Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ORTHODONTICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed1998

Long-term fluoride release of some orthodontic bonding resins: a laboratory study.

OBJECTIVES: The present study compared the amounts and profiles of long term fluoride release from four commercial direct bonding resins (Light-Bond, Reliance Orthodontic Products; Rely.a. Bond, Reliance Orthodontic Products; Orthon, Orthon Dental Inc.; Fluor Ever, Macro-Chem Corporation) and one glass ionomer cement (Ketac-Cem, Espe). METHODS: The specimens were equilibrated in double-deionized water at 37 degrees C. At predetermined intervals, and up to 560 days, the fluoride concentration of the equilibrated solution was determined with a fluoride ion selective electrode. For Light-Bond and Rely.a. Bond two batches were studied and the amount of fluoride released in a 0.1 mol/L NaCl solution was also determined. Differences in the fluoride release profiles due to batch, type of solution and time were determined with a three-factor mixed design ANOVA with repeated measures on one factor. RESULTS: The fluoride release profiles of the orthodontic adhesives studied differ markedly. Initially, Fluor Ever and Ketac-Cem release comparable amounts of fluoride which are greater than those released by Orthon. After a few weeks the amounts of fluoride released by Ketac-Cem and Orthon become comparable, but are considerably higher than those released by Fluor Ever. During the first days of the elution, the amount of fluoride released by Light-Bond equals that of Orthon, but then decreases below the determination limit of the analytical method within half a year. No difference was found between the fluoride release profiles in water and the NaCl solution. However, the fluoride release profiles apparently depend on the batch. For Rely.a. Bond, the amount of fluoride released is smaller than the detection limit for the fluoride analysis. SIGNIFICANCE: The fluoride release of the orthodontic adhesives investigated markedly depends on the mechanisms responsible for the fluoride release process.

Acrylic Resins↗
PubMed1998

Bonding orthodontic brackets with glass-ionomer cement.

This is a clinical paper outlining the experience of an enthusiastic group of seven individuals in different local orthodontic practices who, over a period of six years, have bonded some 99% of the metal orthodontic brackets to tooth enamel using glass ionomer cement (GIC). Up until recently GIC has been little used within the orthodontic world for the cementing of orthodontic brackets, composite resin being the conventional adhesive. We use GIC as a bracket adhesive because there is a very low incidence of tooth enamel decalcification occurring around the brackets with its use compared with the more universally used composite resin adhesives. This paper details the perceived clinical advantages and disadvantages, and then defines the three critical areas for successful bonding with GIC, followed by a description of the chairside technique.

Dental Bonding↗
PubMed1998

Mechanical properties and aesthetics of FRP orthodontic wire fabricated by hot drawing.

The FRP wires 0.5 mm in diameter with a multiple fiber structure were fabricated by drawing the fiber polymer complex at 250 degrees C for an esthetic, transparent orthodontic wire. Biocompatible CaO-P2O5-SiO2-Al2O3 (CPSA) glass fibers of 8-20 microm in diameter were oriented unidirectionally in the longitudinal direction in PMMA matrix. The mechanical properties were investigated by 3-point flexural test. The FRP wire showed sufficient strength and a very good elastic recovery after deformation. Young's modulus and the flexural load at deflection 1 mm were nearly independent of the fiber diameter and linearly increased with the fiber fraction. The dependence on fiber fraction obeys well the rule of mixture. This FRP wire could cover the range of strength corresponding to the conventional metal orthodontic wires from Ni-Ti used in the initial stage of orthodontic treatments to Co-Cr used in the final stage by changing the volume ratio of glass fibers with the same external diameter. The estheticity in external appearance was excellent. Thus the new FRP wire can satisfy both mechanical properties necessary for an orthodontic wire and enough estheticity, which was not possible for the conventional metal wire.

Biocompatible Materials↗
PubMed2000

Reconstruction of an alveolar cleft for orthodontic tooth movement.

Bone grafting to repair an alveolar cleft has long been an integral part of the treatment of persons with unilateral and bilateral clefts of the lip and alveolus. The presence of the cleft places a limitation on the orthodontist who would like to move teeth in the area of the cleft. Various grafting materials have been placed in alveolar clefts in an attempt to solve this problem. The case to be presented is a patient with a Class II, Division 2, malocclusion with a left unilateral alveolar cleft and a repaired cleft lip. Ten months after initiating orthodontic treatment, a free gingival graft procedure was performed because of insufficient vestibular depth and the narrow width of the keratinized attached gingiva at the left maxillary lateral and central incisor region. Two months after periodontal surgery, a mix of decalcified freeze-dried bone allograft and a granular bioactive glass graft material (1:1) were applied subperiostally on the buccal aspect of the edentulous cleft region. Six months later, the teeth adjacent to the grafted alveolar cleft were orthodontically moved into the edentulous area. The treatment results indicated that orthodontic, periodontal, and surgical interventions resulted in a successful closure of the alveolar cleft as well as improved periodontal conditions of the teeth adjacent to the cleft area. From the orthodontic point of view, tooth movement can be achieved successfully into a bone graft made of freeze-dried bone and bioactive glass.

Adolescent↗
PubMed2003

Outcome of orthodontic space closure with a missing maxillary central incisor.

Orthodontic space closure is one of the treatment alternatives when a maxillary central incisor is missing. Because no systematic analysis of such treatment results is available, a sample of 20 consecutively treated patients was examined in a follow-up study. All patients had received orthodontic treatment with the objective of closing the space for the missing central incisor. Biologic features and the clinical appearance of the recontoured lateral incisor (test tooth) replacing the missing tooth were compared with the neighboring intact central incisor, which served as control tooth. The patients' opinions regarding the treatment and the result were recorded in a questionnaire. The position of the examined teeth and the appearance of the surrounding soft tissues were similar in the test and control teeth. However, in some patients (25%), certain aspects of the recontoured incisor crown (such as the width at the gingival margin) mismatched the appearance of the controls. A somewhat increased mobility and probing pocket depth on the mesial aspect was recorded for some test teeth. No obvious detrimental effects were observed on the radiographs. Most patients expressed satisfaction with the treatment result. It is concluded that orthodontic mesialization of the lateral incisor to replace a missing central incisor is a valid treatment modality, if the indications for such treatment are present and careful attention to detail in orthodontic and restorative treatment is exercised.

Adolescent↗
PubMed2003

Orthodontic movement of teeth with intraosseous defects: Histologic and histometric study in dogs.

The purpose of this study was to evaluate histologically, in dogs, the periodontal healing of 1-walled intraosseous defects in teeth that were subjected to orthodontic movement toward the defects. The defects were surgically created bilaterally at the mesial aspects of the maxillary second premolars and distal aspects of the mandibular second premolars of 4 mongrel dogs. One week after creating the defects, an orthodontic appliance was installed, and the teeth were randomly assigned to 1 of 2 treatment groups: those in the test group received a titanium-molybdenum alloy rectangular wire spring that performed a controlled tipping root movement, and those in the control group received a passive stainless steel wire. Active orthodontic movement of the test teeth lasted 2 months and was followed by a stabilization period of another 2 months, after which the animals were killed. Throughout the study, routine daily plaque control was performed on the dogs with a topical application of a 2% chlorhexidine gel. The results showed no difference between the groups, with some regularization of the defects and periodontal regeneration limited to the apical portion of the defects. Histometric analysis showed a significant difference in bone height; on average, it was 0.53 mm smaller in the test group. It was concluded that orthodontic movement does not interfere with the healing of 1-walled intraosseous defects, with the exception of the linear extent of new bone apposition.

Alveolar Bone Loss↗
PubMed2004

In vivo effect of a resin-modified glass ionomer cement on enamel demineralization around orthodontic brackets.

Because the risk of dental caries increases with the use of orthodontic appliances and its control cannot depend only on the patient's self-care, this study evaluated the effect of a glass ionomer cement on reducing enamel demineralization around orthodontic brackets. Fourteen orthodontic patients were randomly divided into 2 groups of 7; they received 23 brackets fitted to their premolars, bonded with either Concise (3M Dental Products, St Paul, Minn), a composite resin (control group), or Fuji Ortho LC (GC America, Chicago, Ill), a resin-modified glass ionomer cement (experimental group). The volunteers lived in a city that has fluoridated water, but they did not use fluoridated dentifrices during the study. After 30 days, the teeth were extracted and longitudinally sectioned; in the enamel around the brackets, demineralization was assessed by cross-sectional microhardness. The determinations were made at the bracket edge cementing limits, and at occlusal and cervical points 100 and 200 microm away from them. In all of these positions, indentations were made at depths from 10 to 90 microm from enamel surface. Analysis of variance showed statistically significant effects for position, material, depth, and their interactions (P<.05). The Tukey test showed that the glass ionomer cement was statistically more efficient than the control, reducing enamel demineralization in all analyses (P<.05). The use of glass ionomer cement for bonding can be encouraged because it decreases the development of caries around orthodontic brackets.

Acrylic Resins↗
PubMed2003

Long-term in vitro fluoride release and rerelease from orthodontic bonding materials containing fluoride.

The purpose of this study was to compare in vitro long-term (30 month) fluoride release and rerelease rates (after fluoride exposure) from 3 orthodontic bonding materials containing fluoride and 1 without fluoride. Ten samples of each material (Python, TP Orthodontics, LaPorte, Ind; Assure, Reliance Orthodontic Products, Itasca, Ill; Fuji Ortho LC, GC America, Alsip, Ill; and Transbond XT, 3M Unitek, Monrovia, Calif) were fabricated and stored in deionized distilled water at 37 degrees C. Five samples had fluoride-release rates measured at days 546, 637, 730, 821, and 913 after initial fabrication, and 5 samples were exposed to fluoride (Nupro 2% NaF gel, Dentsply Canada, Woodbridge, Ontario, Canada) for 4 minutes at day 535 and had measurements taken on days 546, 548, 552, 575, 637, 730, 821, and 913. To prevent cumulative measurements, the storage solutions were changed 24 hours before measurement. Statistically significant differences were found in fluoride-release rates (P <.0001), with Fuji Ortho LC releasing the most fluoride, followed by Python and Assure at all time points in the nonfluoride exposed group. In the fluoride-exposed group, there were significant differences in fluoride release (P <.0001), with Fuji Ortho LC releasing the most fluoride. A "burst-effect" pattern of fluoride release was seen after fluoride exposure for all materials. It was concluded that Fuji Ortho LC, Assure, and Python might have sufficient long-term fluoride-release rates to reduce white spot formation, and all are recommended as suitable fluoride-releasing orthodontic bonding materials.

Acrylic Resins↗
PubMed1990

Effects of orthodontic bands on microbiologic and clinical parameters.

The aim of this study was to evaluate the effect of placement of orthodontic bands on the gingival tissues and the microbial composition of dental plaque. Ten subjects undergoing orthodontic treatment completed the study. In each subject four sites were examined: two test sites with orthodontic bands and two control sites free of bands. Clinical and bacterial examinations were performed before the beginning of the treatment and 5, 7, 47, 72, and 90 days after placement of the orthodontic appliances. Plaque index (Pl I) and bleeding scores increased significantly on banded teeth as compared with control sites. Probing depth remained within normal values for both test and control groups. The composition of dental plaque determined by dark-field microscopy showed significant shifts in the test sites after banding. Changes consisted of an increase in the percentage of spirochetes, motile rods, filaments, and fusiforms; conversely, a decrease in cocci was noted. During the same period no significant changes in the bacterial distribution were observed in the control group.

Adolescent↗
PubMed1990

Shear bond strength of ceramic orthodontic brackets to enamel.

The recent introduction of ceramic orthodontic brackets has generated interest among orthodontists. The aim of this investigation was to evaluate the in vitro shear bond strengths to enamel of four ceramic orthodontic brackets and one stainless steel bracket in trials with two separate acid-etching times for enamel. Eighty extracted human central incisors were prepared for bonding to Starfire, Allure, Transcend, Quasar, and stainless steel (in the control group) orthodontic bracket systems. Enamel etching times of 15 seconds and 60 seconds were used. There was a total of 10 groups. After acid etching, one coat of low-viscosity bonding agent was applied and the brackets were bonded to etched enamel with Concise orthodontic bonding resin. The bonded test specimens were stored in distilled water at 37 degrees C for 14 days, after which they were thermocycled for 500 cycles (5 degrees C to 60 degrees C). The bonds were stressed to failure in an Instron machine at a crosshead speed of 0.02 inch per minute. The shear bond strengths were calculated and Weibull analysis was used to obtain a shape factor (the slope of the straight line and a measure of predictability) and the characteristic level (the 63.2% bond strength value of median rank on the strength line) for each group. Predictability and high bond strength, along with other factors, are important in the clinical selection of a bracket system. When either predictability or bond strength was considered independently, several bracket systems, coupled with a particular etch time, had either high predictability or high bond strength. The highest predictability and the highest bond strength were both found with the Allure bracket system.

Acid Etching, Dental↗
PubMed1991

Adolescent suicide in orthodontics: results of a survey.

Suicide among adolescents is a psychosocial problem that confronts today's teenagers and society in alarming proportions. The wounds from this tragedy scar adolescents and their families both physically and emotionally. By virtue of a tradition for early treatment and the periodic nature of orthodontic care during critical psychologic development, the orthodontist is in a position to recognize early warning signs of adolescent suicide. A survey of 1000 practicing orthodontists and 54 department chairpersons of orthodontic postgraduate programs assessed the relevance of this issue to the profession, the nature of educational information previously and currently available in orthodontic curricula, and the frequency with which suicidal behavior is noted in orthodontic practice. Guidelines for recognition and intervention are provided. The results indicate that (1) adolescent suicide is of concern to orthodontists, (2) academic information has focused on the general aspects of psychology but not on the recognition and intervention, and (3) 50% of those surveyed have had at least one patient attempt suicide, whereas 25% have had a young patient actually commit suicide.

Adolescent↗
PubMed1994

The effect of ibuprofen on the level of discomfort in patients undergoing orthodontic treatment.

Studies have shown that patients undergoing orthodontic tooth movement can experience varying degrees of discomfort. The objective of this study was to determine whether nonsteroidal antiinflammatory agents, such as aspirin or ibuprofen, which inhibit prostaglandin synthesis through acetylation and inactivation of the enzyme cyclooxygenase, can suppress orthodontic discomfort by inhibiting the inflammatory response normally observed after orthodontic adjustments. A total of 77 patients were included in a double-blind, randomized, parallel, placebo-controlled, single-dose, analgesic efficacy evaluation of ibuprofen and aspirin. Patients were divided into three groups. Group A received one dose of the drug ibuprofen (400 mg), group B received aspirin (650 mg), and group C received a placebo (beta-lactose). The level of discomfort was assessed using a visual analogue scale at 2, 6, and 24 hours and 2, 3, and 7 days after the insertion of either orthodontic separators or an initial arch wire. A repeated measures analysis of variance and post hoc studentized range statistics showed that the placebo group had significantly more discomfort than either the ibuprofen or the aspirin group at all the time intervals tested. In addition, ibuprofen produced significantly less discomfort than aspirin at the 6 and 24-hour and 2-day time phase after separator placement; and 2 and 6 hours and 2, 3, and 7 days after arch wire placement. These results support a recommendation for ibuprofen as a preferred analgesic in the treatment of discomfort because of postorthodontic adjustments.

Adolescent↗
PubMed1994

Determination of the tooth mobility change during the orthodontic tooth movement studied by means of Periotest and MIMD (the mechanical impedance measuring device for the periodontal tissue).

Two mechanical devices were selected to attempt to assess any changes in tooth mobility when orthodontic force was applied. A Periotest (PT) for assessing mobility and a mechanical impedance measuring device (MIMD) were the instruments chosen to diagnose the changes in the periodontal condition. The relative mobility of four canines after orthodontic tooth movement manipulation was assessed over a 4-week period. Both devices were able to detect very small changes in tooth mobility and could follow the changes during tooth movement. According to the Periotest unit, the tooth mobility changes were not within the clinically abnormal range, despite the initial retraction load from a sectional arch, applied in a horizontal direction with about 150 gm for each tooth. In all instances, the contiguous maxillary first premolar had been removed 1 to 2 months before force application. The tooth mobility observed in this investigation could be different from that caused by periodontal disease or traumatic injury. Just after orthodontic tooth movement manipulation, the Periotest values (PTV), as measured on the Periotest, of tooth mobility decreased and the resistance as measured by the mechanical impedance measuring device (MIMDM) was increased. Thus, initially, there is a greater resistance to movement with decreased mobility. After the experimental period of 4 weeks, there was an increase in the mobility, as measured by the Periotest and the mechanical resistance decrements were observed. However, the Periotest units showed some different changes occasionally that did not seem to reflect the state of tooth movement. This needs to be investigated further over a longer period of time. On the basis of the results obtained, it does appear that it is feasible to use these devices to determine mobility changes in patients at various stages of orthodontic treatment.

Cuspid↗
PubMed1994

The effect of titanium tetrafluoride (TiF4) application around orthodontic brackets.

In the present in vivo study, the cariostatic potential of a titanium tetrafluoride (TiF4) solution applied topically around orthodontic brackets was investigated with quantitative microradiography. Also characteristics of the TiF4-treated enamel surface were examined with scanning electron microscopy (SEM). Ten pairs of premolars to be extracted for orthodontic treatment were used in the first part of this study. Brackets were bonded on all teeth with an orthodontic adhesive, and 10 randomly selected premolars served as controls, whereas a similar number were treated with 1% TiF4 around brackets for 60 seconds. After 4 weeks with no topical fluoride supplementation, all teeth were extracted and stored for analysis. Results indicated the 1% TIF4 solution reduced lesion depths and total mineral loss, at the bracket periphery, significantly during the 4-week period. The presence of a surface coating was demonstrated by SEM micrographs. It was concluded that TiF4 may provide a high level performance as a prophylactic agent for orthodontic purposes.

Child↗
PubMed1996

Application of a classical model of competitive business strategy to orthodontic practice.

This study explored how market forces might affect the business aspects of orthodontic practices; in particular, profitability. The forces identified were (1) intensity of rivalry, (2) threat of new entrants, and (3) bargaining power of buyers and suppliers. A mail survey instrument was used to collect the data. Results showed that more than half the surveyed practices show an increase in new case starts despite weak economic conditions. Although satellite offices and marketing increase the overhead, they do not add to net profit. New entrants are a threat to existing practices, as are the substitute discretionary spending by the consumer. Interestingly, while some orthodontic practices have joined the managed care programs, a majority of them realize neither increased patient load nor profit. Our data seem to indicate that orthodontic practices have not been successful in "cost containment" with their marketing, number of employees, computerization or inventory. Collectively, the results of this study suggest that success in an orthodontic office is primarily dependent on the practitioner's personality traits, rather than rigidly applied business principles.

Attitude of Health Personnel↗
PubMed1997

Mutans streptococci and incipient caries adjacent to glass ionomer cement or resin-based composite in orthodontics.

Levels of mutans streptococci in plaque adjacent to orthodontic brackets retained with a glass ionomer cement (GIC) (Ketac-Cem) and a resin-based composite (CR) (Concise) were investigated, using the split mouth technique in 11 patients who, before treatment, had more than 10(5) CFU of these microorganisms. After full-term orthodontic treatment (mean 9.5 months), the percentage of mutans streptococci of total CFU count in plaque was lower adjacent to GIC-retained brackets (mean 3.9) than adjacent to CR-retained brackets (6.7), but the difference was not statistically significant. Two subjects harbored S. sobrinus. These subjects were the only ones who developed incipient caries during the orthodontic treatment. Incipient lesion formation occurred only adjacent to CR-retained brackets. This suggests that in patients who have relatively high salivary levels of mutans streptococci before treatment and especially in those who harbor S. sobrinus, the use of GIC for bonding may prevent incipient caries formation during orthodontic treatment.

Adolescent↗
PubMed1998

Enamel demineralization adjacent to orthodontic brackets bonded with hybrid glass ionomer cements: an in vitro study.

Enamel demineralization is recognized as a possible side effect of bonding orthodontic brackets with composite resins. Fluoride-releasing restorative materials have been shown to inhibit tooth demineralization. The purpose of this study was to evaluate two fluoride-releasing hybrid glass ionomer bonding agents for inhibition of enamel demineralization surrounding orthodontic brackets under two experimental conditions. This in vitro study used 72 extracted human premolars. Twenty-four teeth were bonded with Advance resionomer, 24 were bonded with Fuji Ortho LC hybrid glass ionomer and 24 were bonded with Transbond XT composite resin as the control. The teeth were cycled in an artificial caries challenge three times daily for 30 days. Half of the teeth in each group were brushed twice daily with a fluoridated dentifrice, and the other half were not brushed. Demineralization of enamel surrounding orthodontic brackets was evaluated with polarized light microscopy. Enamel lesions were photographed under maximum illumination. Images were projected, and demineralized areas were traced. Both average depth and area were measured with a sonic digitizer. Analysis of variance (P <.0001) and Duncan's test (P <.05) indicated significant differences in depth and area of demineralized enamel such that lesion size was: Transbond XT no brush > Transbond XT brush > Advance no brush = Advance brush = Fuji Ortho LC no brush = Fuji Ortho brush. The promising results of this in vitro study warrant further clinical investigation of hybrid glass ionomer adhesives as orthodontic bonding agents to minimize enamel demineralization.

Acrylic Resins↗
PubMed1998

A longitudinal laser fluorescence study of white spot lesions in orthodontic patients.

Orthodontic treatment with fixed appliances increases the caries risk in young persons. The aim of this study was to apply a new caries diagnostic method, quantitative laser fluorescence, for longitudinal in vivo quantification of changes in incipient enamel lesions related to fixed orthodontic appliances. Seven young patients with active caries lesions disclosed at removal of the orthodontic brackets and bands were enrolled in the study. Caries preventive measures were intensified, including dietary advice, oral hygiene instructions, and the regular use of a fluoride dentifrice. The caries lesions were monitored with the quantitative laser fluorescence method after removal of the brackets and once a month thereafter. For each lesion, three quantities were measured: lesion area (mm2), mean fluorescence loss (%) over the lesion, and maximum loss of fluorescence (%) in the lesion. During a 1-year follow-up period, the areas of the lesions decreased and the enamel fluorescence lost was partly regained indicating that a remineralization process had occurred. It was concluded that quantitative laser fluorescence seems suitable for in vivo monitoring of mineral changes in incipient enamel lesions, and useful for the evaluation of preventive measures in caries prone persons, such as orthodontic patients.

Adolescent↗