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1.
AORN J ; 108(6): 634-642, 2018 12.
Article in English | MEDLINE | ID: mdl-30480793

ABSTRACT

There are many sources of contamination in the perioperative environment. Patient experience can be negatively affected by the presence of environmental contamination, especially if it is the cause of a surgical site infection. Perioperative and environmental services staff members and leaders are tasked with ensuring a clean and safe environment for their patients while maintaining an awareness of time and budgetary constraints. In addition, leaders are responsible for the competency of their staff members and must address performance issues when needed. New technological advances designed to streamline monitoring and reporting processes related to OR cleanliness are available for use. This article describes the quality improvement project that one multifacility organization completed related to the use of remote video auditing and the positive effect it had on the organization's environmental contamination.


Subject(s)
Disinfection/standards , Housekeeping, Hospital , Operating Rooms , Video Recording , Cross Infection/prevention & control , Equipment Contamination , Feedback , Humans , New England , Quality Improvement
2.
Front Public Health ; 5: 221, 2017.
Article in English | MEDLINE | ID: mdl-28879177

ABSTRACT

INTRODUCTION: Orthodontic treatment is reimbursed by Medicaid based on orthodontic and financial need with qualifiers determined by individual states. Changes in Medicaid-funded orthodontic treatment following the "Great Recession" in 2007 and the enactment of the Affordable Care Act in 2010 were compared for the 50 United States and the District of Columbia to better understand disparities in access to care. The results from this 2015 survey were compared to data gathered in 2006 (1). MATERIALS AND METHODS: Medicaid officials were contacted by email, telephone, or postal mail regarding the age limit for treatment, practitioner type who can determine eligibility and provide treatment, records required for case review, and rate and frequency of reimbursement. When not attained by direct contact, the information was gleaned from online websites, provider manuals, and state orthodontists. RESULTS: Information gathered from 50 states and the District of Columbia documents that Medicaid program characteristics and expenditures continue to vary by state. Expenditures and reimbursement rates have decreased since 2006 and vary widely by geographic region. Some states have tightened restrictions on qualifiers and increased submission requirements by providers. CONCLUSION: The variation and lack of uniformity that still exists among Medicaid orthodontic programs in different states creates disparities in orthodontic care for US citizens. Barriers to care for Medicaid-funded orthodontic treatment have increased since 2006.

3.
Am J Orthod Dentofacial Orthop ; 149(1): 15-23, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26718373

ABSTRACT

INTRODUCTION: The use of a compound topical anesthetic (CTA) instead of an injection of a local anesthetic for placing miniscrew implants offers advantages to both the clinician and the patient. The purpose of this crossover, prospective, randomized clinical trial was to compare the clinical effectiveness of a CTA with that of a needle injection of local anesthetic for miniscrew placement. METHODS: Twenty-four orthodontic patients in a university clinic were recruited; they required bilateral buccal miniscrews for orthodontic anchorage. Eligibility criteria included healthy patients with no special needs; over 8 years of age and 25 pounds; not taking sulfonamides, monoamine oxidase inhibitors, tricyclic antidepressants, or phenothiazines; and not allergic to ester-type local anesthetics or any of the other materials used in the study. A computer generated a randomization list. The allocation was randomized by anesthetic protocol and side of the mouth, and was restricted to achieve balance by treatment and side of the mouth. No allocation concealment was applied. Associated with each randomized number was the subjects' assignment into 1 of 4 groups divided by the side of first miniscrew placement and the type of anesthetic. Blinding was done only for data analysis because of clinical limitations. Each patient received a CTA on one side and an injection of anesthetic on the other before miniscrew placement in a crossover study design. The outcome was assessed by measuring pain levels with a 100-mm visual analog scale at 5 time points. Anesthetic failures occurred when the miniscrew could not be fully comfortably placed with a given anesthetic. Data were organized by visual analog scale time points, and descriptive statistics were calculated. A factorial repeated-measures analysis of variance was used to determine any differences. RESULTS: Twenty-seven patients were assessed for eligibility, and 24 agreed to participate in the study. Patients did not distinguish any differences in pain between the application of the CTA and the injection before or during anesthetic placement, but they experienced more pain with the CTA during miniscrew placement. The mean difference for the entire procedure between the 2 anesthesia types was 24.6 units, and the 95% confidence interval was 18.8 to 30.4, a statistically significant finding (P = 0.0002). The CTA was still viewed as more painful 1 month after the procedures. Significantly more anesthetic failures occurred with the CTA (41.6%) than with the injection (0%). No serious harm was observed in any patient; when significant pain was observed with the CTA, a needle injection of local anesthetic was administered. CONCLUSIONS: CTAs provided less predictable, often inadequate, and less comfortable anesthesia than an injection of a local anesthetic for managing patient discomfort during miniscrew placement in buccal sites. REGISTRATION: This trial was not registered. PROTOCOL: The protocol was determined and approved by the research committee and institutional review board before the trial. FUNDING: No external funding was used other than the donation of the miniscrews from Rocky Mountain Orthodontics, and no conflict of interest was declared.


Subject(s)
Anesthesia, Dental/methods , Anesthetics, Combined/administration & dosage , Anesthetics, Local/administration & dosage , Bone Screws , Orthodontic Anchorage Procedures/instrumentation , Pain Measurement/methods , Pain Perception/physiology , Administration, Topical , Adolescent , Adult , Cross-Over Studies , Female , Humans , Injections/instrumentation , Lidocaine/administration & dosage , Male , Middle Aged , Miniaturization , Needles , Pain/prevention & control , Prilocaine/administration & dosage , Prospective Studies , Tetracaine/administration & dosage , Treatment Outcome , Vasoconstrictor Agents/administration & dosage , Young Adult
4.
BMJ Qual Saf ; 25(12): 947-953, 2016 12.
Article in English | MEDLINE | ID: mdl-26658775

ABSTRACT

IMPORTANCE: Compliance with the surgical safety checklist during operative procedures has been shown to reduce inhospital mortality and complications but proper execution by the surgical team remains elusive. OBJECTIVE: We evaluated the impact of remote video auditing with real-time provider feedback on checklist compliance during sign-in, time-out and sign-out and case turnover times. DESIGN, SETTING: Prospective, cluster randomised study in a 23-operating room (OR) suite. PARTICIPANTS: Surgeons, anaesthesia providers, nurses and support staff. EXPOSURE: ORs were randomised to receive, or not receive, real-time feedback on safety checklist compliance and efficiency metrics via display boards and text messages, followed by a period during which all ORs received feedback. MAIN OUTCOMES AND MEASURES: Checklist compliance (Pass/Fail) during sign-in, time-out and sign-out demonstrated by (1) use of checklist, (2) team attentiveness, (3) required duration, (4) proper sequence and duration of case turnover times. RESULTS: Sign-in, time-out and sign-out PASS rates increased from 25%, 16% and 32% during baseline phase (n=1886) to 64%, 84% and 68% for feedback ORs versus 40%, 77% and 51% for no-feedback ORs (p<0.004) during the intervention phase (n=2693). Pass rates were 91%, 95% and 84% during the all-feedback phase (n=2001). For scheduled cases (n=1406, 71%), feedback reduced mean turnover times by 14% (41.4 min vs 48.1 min, p<0.004), and the improvement was sustained during the all-feedback period. Feedback had no effect on turnover time for unscheduled cases (n=587, 29%). CONCLUSIONS AND RELEVANCE: Our data indicate that remote video auditing with feedback improves surgical safety checklist compliance for all cases, and turnover time for scheduled cases, but not for unscheduled cases.


Subject(s)
Checklist/standards , Efficiency, Organizational/standards , Medical Audit/methods , Operating Rooms/standards , Patient Safety/standards , Formative Feedback , Guideline Adherence , Humans , Patient Care Team/standards , Practice Guidelines as Topic , Prospective Studies , Text Messaging , Videotape Recording
5.
Am J Orthod Dentofacial Orthop ; 143(4 Suppl): S55-63, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23540637

ABSTRACT

INTRODUCTION: Recently, manufacturers have marketed alginate impression materials, claiming dimensional stability for up to 100 hours to allow shipping to a dental laboratory for digital model fabrication. The purpose of this study was to evaluate the dimensional changes of these newer materials after storage at different temperatures and times. METHODS: Two extended-pour alginates (claiming 100 hours of accuracy) (Kromopan; Lascod, Florence, Italy; and Triphasix; Parkell, Edgewood, NY), 2 traditional alginates (Jeltrate; Dentsply-Caulk, York, Pa; and Kromatica; Matech, Sylmar, Calif), and 1 vinyl polysiloxane (VP Mix; Henry Schein, Melville, NY) were used to impress a scored aluminum die. The distance between the score lines was measured on the impressions at 10 minutes, 24 hours, and 100 hours after mix, and the percentages of dimensional change were calculated. Temperature effects were studied by storage at cold (-9°C), room (22°C), or hot (46°C) temperatures for 8 hours. RESULTS: All alginates had statistically significant dimensional changes at 24 and 100 hours (0.69%-6.13%). VP Mix exhibited no statistically significant changes for any storage condition. The Kromopan (100 hour) and Kromatica (traditional) alginates were the most stable (0.85%-2.22% at 100 hours). Triphasix (100 hour) and Jeltrate (traditional) were the least stable (1.53%-4.73% at 100 hours). Cold-temperature storage resulted in the most dimensional changes (1.96%-4.73% at 100 hours). Room-temperature storage resulted in the least dimensional changes (0.97%-1.53% at 100 hours). CONCLUSIONS: All alginate impression materials in the study had significant changes at 24 and 100 hours in all storage conditions tested.


Subject(s)
Alginates , Dental Impression Materials , Dimensional Measurement Accuracy , Elastomers , Image Processing, Computer-Assisted , Materials Testing , Models, Dental , Temperature
6.
Am J Orthod Dentofacial Orthop ; 141(3): 298-306, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22381490

ABSTRACT

INTRODUCTION: Orthodontists depend on perceptions derived from education and clinical experience to judge the optimal forces in patient treatment. The purpose of this study was to survey practicing orthodontists to determine the interarch latex elastic forces they prescribe in different malocclusion scenarios. METHODS: Thirty orthodontists were presented with 4 clinical scenarios on study models, including Class II and Class III malocclusions in edgewise and light wires. These orthodontists described the size and location of the elastics they would use. The forces produced by the prescribed elastics were measured and compared with actual dry forces measured on a testing machine. RESULTS: The orthodontists' force recommendations were a mean of 277 ± 89 g and a median of 256 g (range, 132-464 g) for a Class II malocclusion with edgewise wires; a mean of 183 ± 59 g and a median of 177 g (range, 59-284 g) for a Class II malocclusion with light wires; a mean of 290 ± 83 g and a median of 305 g (range, 151-562 g) for a Class III malocclusion with edgewise wires; and a mean of 216 ± 66 g and a median of 209 g (range, 119-344 g) for a Class III malocclusion with light wires. The force levels for light wires were statistically significantly lower than for edgewise wires. CONCLUSIONS: There were considerable variations in the forces selected for all cases. "Expert" recommendations fell within 1 SD of the mean of the orthodontists' recommendations except for the light-wire Class III scenario. Since latex elastic force decays significantly during a patient's use, elastics should be selected with initially higher forces than desired.


Subject(s)
Elastomers/chemistry , Latex/chemistry , Orthodontic Appliances , Biomechanical Phenomena , Dental Alloys/chemistry , Dental Stress Analysis/instrumentation , Elastic Modulus , Humans , Malocclusion, Angle Class II/therapy , Malocclusion, Angle Class III/therapy , Models, Dental , Orthodontic Appliance Design , Orthodontic Brackets , Orthodontic Wires , Orthodontics , Practice Patterns, Dentists' , Stainless Steel/chemistry , Stress, Mechanical
7.
Dent Mater ; 26(7): 697-703, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20381138

ABSTRACT

OBJECTIVE: Stress development at the tooth/restoration interface is one of the most important reasons for failure of adhesive restorations. The aim of this study was to evaluate the influence of BisGMA/TEGDMA (B/T) and UDMA/TEGDMA (U/T) ratios on polymerization stress (PS) and on the variables related to its development: degree of conversion (DC), polymerization maximum rate (Rp(max)), volumetric shrinkage (VS), elastic modulus (E), stress relaxation (SR) and viscosity of experimental composites. METHOD: Composites were formulated containing B/T or U/T in mol% ratios of 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 and 8:2, and 15 wt% of fumed silica. PS was determined with a universal testing machine. VS was measured with a linometer. E and SR were obtained in three-point bending. DC and Rp(max) were determined by real time NIR spectroscopy and viscosity was measured in viscometer. Data were submitted to one-way ANOVA, Tukey test (alpha=0.05%) and regression analyses. RESULTS: PS, VS, E and DC decreased and viscosity and Rp(max) increased with base monomer content in both series. PS showed strong correlation with VS, DC and viscosity. PS, VS and DC were higher and viscosity was lower for UDMA-based materials. SIGNIFICANCE: Reduced viscosity, kinetics parameters and molecular characteristics led UDMA-based composites to elevated conversion and relatively lower PS at lower TEGDMA contents, compared to B/T composites.


Subject(s)
Composite Resins/chemistry , Light-Curing of Dental Adhesives , Analysis of Variance , Bisphenol A-Glycidyl Methacrylate , Dental Marginal Adaptation , Dental Stress Analysis , Elastic Modulus , Kinetics , Materials Testing , Methacrylates , Phase Transition , Polyethylene Glycols , Polymethacrylic Acids , Polyurethanes , Regression Analysis , Viscosity
8.
Acta Biomater ; 6(6): 2053-9, 2010 Jun.
Article in English | MEDLINE | ID: mdl-19913646

ABSTRACT

Optical properties of composite restoratives, both cured and uncured, are of obvious importance in a procedure reliant on photoactivation, since they may affect light transmission and therefore materials conversion upon which mechanical properties and ultimate clinical performance are dependent. The objective of the present study was to evaluate simultaneous, real-time conversion, and the development of the temperature and optical properties. The dimethacrylate resin (Bis-GMA/TEGDMA 70/30mass%) was prepared at three filler loading (0, 35 or 70mass%: no fill, low and high fill, respectively) combined with three initiator concentrations (CQ/EDMAB: 0/0, 0.2/0.8 or 1.0/1.6mass%). Specimens were exposed to either low (50mWcm(-2)) or high (500mWcm(-2)) irradiance. Simultaneous conversion (near-IR peak area), temperature (thermocouple) and visible light transmission (UV-vis spectroscopy) measurements were conducted throughout the polymerization process. The refractive index of the resin rises linearly with conversion (r(2)=0.976), producing a refractive index match between resin/filler at approximately 58% conversion in these materials. The percentage increase in light transmission during conversion was greater for increasing filler levels. Higher CQ content led to maximum light transmission at slightly higher levels of conversion (60-65% and 50-55% for the high and low filled materials, respectively). The broad distribution of filler concentrations allows for the clinically relevant generalization that highly filled composites not only jeopardize absolute light transmission, conversion and depth of cure, but also demonstrate the complex interrelationship that exists between materials, processing conditions and the optical properties of dental composites.


Subject(s)
Biocompatible Materials/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Bisphenol A-Glycidyl Methacrylate/radiation effects , Photochemistry/methods , Crystallization/methods , Hardness , Light , Manufactured Materials/analysis , Manufactured Materials/radiation effects , Materials Testing , Refractometry , Temperature
9.
Am J Orthod Dentofacial Orthop ; 136(1): 83-6, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19577152

ABSTRACT

INTRODUCTION: In testing bond strengths, various storage media are used. The purpose of this study was to determine the effect of 6 storage media and rinsing on the shear bond strength of bonded orthodontic brackets. METHODS: Bovine teeth were stored in 6 storage media for 7 months before bonding: dry (no medium), filtered water, 10% formalin, 1% chloramine T, 10% chloramine T, isotonic saline solution, and 70% ethanol. These teeth were further subdivided into 2 groups; 1 group was rinsed with oil-free air and water spray before bonding orthodontic brackets, and the other group not rinsed. All specimens were tested in the shear-peel mode to failure. RESULTS: The 10% formalin rinsed sample had statistically significantly higher bond strength (16.9 +/- 6.56 MPa), and storage in ethanol (rinsed, 9.04 +/- 5.61 MPa; not rinsed, 9.08 +/- 3.5 MPa) and dry (8.34 +/- 3.80 MPa) produced significantly lower bond strengths. No difference was found between the other modes of storage or rinsing. The adhesive remnant index values showed no statistically significant difference between any groups. CONCLUSIONS: For bond strength studies, storage media can have an effect on bond strength results. Dry, formalin, and ethanol storage should be avoided. Water, isotonic saline solution, and chloramine T storage produced comparable bond strengths. Rinsing or not rinsing had no effect on bond strength with these storage media.


Subject(s)
Dental Bonding , Organ Preservation Solutions/chemistry , Orthodontic Brackets , Tooth , Adhesiveness , Air , Animals , Bisphenol A-Glycidyl Methacrylate/chemistry , Cattle , Chloramines/chemistry , Dental Enamel/ultrastructure , Desiccation , Disinfectants/chemistry , Ethanol/chemistry , Formaldehyde/chemistry , Isotonic Solutions/chemistry , Resin Cements/chemistry , Shear Strength , Sodium Chloride/chemistry , Stress, Mechanical , Surface Properties , Temperature , Therapeutic Irrigation , Time Factors , Tosyl Compounds/chemistry , Water/chemistry
10.
Am J Orthod Dentofacial Orthop ; 135(6): 771-6, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19524837

ABSTRACT

INTRODUCTION: Amorphous calcium phosphate, antibacterial monomer MDPB (12-methacryloyloxydodecyl-pyridinium bromide), and self-etching primers are some of the novel elements now added to bonding systems. The purpose of this study was to compare bond strengths of newer bonding systems with either bioactive components or self-etching primers with a conventional bonding system. METHODS: Four new bonding systems, Aegis Ortho (with amorphous calcium phosphate) (Harry J. Bosworth, Skokie, Ill), Clearfil Protect Bond (self-etching primer with an antibacterial monomer) (Kuraray Dental, Kurashiki, Japan), iBond (reformulated self-etching primer) (Heraeus Kulzer, Hanau, Germany), and Clearfil S3 Bond (self-etching primer with combined hydrophilic and hydrophobic technology) (Kuraray Dental), were tested and compared with Transbond XT, a conventional bracket bonding system (3 M Unitek, Monrovia, Calif). Brackets bonded with these materials were tested in the shear-peel mode at 30 minutes and 24 hours, and the location of the bond failures was observed. RESULTS: The newer bonding systems Aegis Ortho (5.3 +/- 0.5 MPa at 30 minutes, 7.2 +/- 0.7 MPa at 24 hours), Clearfil Protect Bond (7.1 +/- 0.8 MPa at 30 minutes, 6.1 +/- 0.6 MPa at 24 hours), Clearfil S3 Bond (3.8 MPa at 30 minutes, 6.6 +/- 0.5 MPa at 24 hours), and iBond (3.9 +/- 0.4 MPa at 30 minutes, 3.9 +/- 0.3 MPa at 24 hours) achieved shear bond strengths significantly lower than Transbond XT (10.1 +/- 0.8 MPa at 30 minutes, 10.1 +/- 1.0 MPa at 24 hours). CONCLUSIONS: Aegis Ortho, Clearfil Protect Bond, Clearfil S3 Bond, and iBond produced lower bond strengths than did Transbond XT, with iBond's strength lower than what might be acceptable for clinical usefulness.


Subject(s)
Dental Bonding , Dental Cements/chemistry , Orthodontic Brackets , Acid Etching, Dental/methods , Animals , Calcium Phosphates/chemistry , Cattle , Dental Enamel/ultrastructure , Dental Stress Analysis/instrumentation , Dentin-Bonding Agents/chemistry , Materials Testing , Pyridinium Compounds/chemistry , Resin Cements/chemistry , Stress, Mechanical , Surface Properties , Time Factors
11.
Am J Orthod Dentofacial Orthop ; 135(4): 516-21, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19361739

ABSTRACT

INTRODUCTION: Some patients undergoing orthodontic treatment report enough discomfort to affect their compliance or request treatment termination. The purpose of this preliminary study was to test the effectiveness of ibuprofen vs acetaminophen in controlling discomfort after initial orthodontic appliance and archwire placement. METHODS: A total of 60 patients (ages, 12-18 years) undergoing fixed comprehensive orthodontic treatment were randomly assigned to 1 of 3 experimental groups: 600 mg of acetaminophen, 400 mg of ibuprofen, or a placebo. All subjects were instructed to take the medications orally at prescribed times after initial appliance and archwire placement. Each patient's level of discomfort was assessed with a 100-mm visual analog scale immediately after placement; at 3, 7, 19, 24, 31, and 48 hours; and at 3, 4, and 7 days. RESULTS: The results indicated that the peak level of pain was at 19 hours after placement, and the differences in scores among the 3 groups were not statistically significant. CONCLUSIONS: Acetaminophen, ibuprofen, and placebo are equally effective in reducing discomfort after initial orthodontic appliance placement.


Subject(s)
Acetaminophen/therapeutic use , Analgesics, Non-Narcotic/therapeutic use , Ibuprofen/therapeutic use , Orthodontic Appliances/adverse effects , Pain/drug therapy , Tooth Movement Techniques/adverse effects , Adolescent , Child , Female , Follow-Up Studies , Humans , Male , Orthodontics, Corrective/instrumentation , Pain/etiology , Pain Measurement , Pilot Projects , Treatment Outcome
12.
Am J Orthod Dentofacial Orthop ; 132(5): 578.e1-6, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18005829

ABSTRACT

INTRODUCTION: Enamel decalcification is a potential problem that can compromise the esthetic results of orthodontic treatment. Patient compliance with preventive measures is frequently inadequate to resolve this issue. The purpose of this study was to determine the effectiveness of sealing around the bracket periphery in reducing decalcification. METHODS: Sixty extracted teeth were collected and randomized to 4 groups: group 1, bonded and then sealed around the bracket with an unfilled sealant material; group 2, bonded and then sealed with a filled, flowable composite material; group 3, bonded and sealed with excess bracket adhesive contoured at bracket periphery; and group 4, conventional treatment with excess bonding material removed and no additional protection at the bracket periphery. Each group was subjected to mechanical, thermal, and decalcification challenges to simulate in-vivo conditions. RESULTS: Groups 1 and 2 had the lowest incidence of decalcification; however, decalcification was not statistically significantly reduced by the use of an additional restorative/bracket adhesive material. An incidental finding was a statistically significant loss of bracket adhesive material beneath the bracket pads of group 4. CONCLUSIONS: Prophylactic sealing around the orthodontic bracket pad periphery with an unfilled sealant or a filled flowable composite restorative material did not significantly reduce the incidence of decalcification.


Subject(s)
Dental Restoration, Permanent/methods , Orthodontic Brackets/adverse effects , Pit and Fissure Sealants , Resin Cements , Tooth Demineralization/prevention & control , Bicuspid , Humans , Molar , Statistics, Nonparametric , Tooth Demineralization/etiology
13.
Dent Mater ; 20(8): 766-77, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15302457

ABSTRACT

OBJECTIVES: This study was conducted to determine the effect of modest external heating on the photopolymerization kinetics and conversion of commercial dental composite restorative materials. METHODS: A transmission-mode, real-time near-infrared spectroscopic technique was used to monitor the photopolymerization process in the composite materials at various temperatures between 23 and 70 degrees C. Several light curing units, differing in spectral output and power densities were compared at the different cure temperatures. Several significantly different commercial composites were compared for their response. RESULTS: Regardless of the curing light or composite material used, photopolymerization at a moderate curing temperature of 54.5 degrees C resulted in significantly higher immediate and final conversion values compared with room temperature photocuring. Contrary to the room temperature cured materials, at the elevated cure temperature the extent of post-cure was minor and different curing lights produced very uniform conversion values within a given material. The time required to reach a given level of conversion, established as full conversion with the room temperature cure, was reduced typically by 80-90% using the elevated curing conditions. Complementary kinetic studies confirmed the effect of cure temperature on increasing the polymerization rate in dental composites as significant. SIGNIFICANCE: Increasing the temperature of composite resin within potentially biologically compatible limits can significantly influences resin polymerization. These increased rates and conversion could lead to improved properties of composite restorative materials.


Subject(s)
Composite Resins/chemistry , Dental Materials/chemistry , Analysis of Variance , Biocompatible Materials/chemistry , Biocompatible Materials/radiation effects , Composite Resins/radiation effects , Dental Materials/radiation effects , Hot Temperature , Humans , Light , Lighting/instrumentation , Polymers/chemistry , Polymers/radiation effects , Resin Cements/chemistry , Resin Cements/radiation effects , Spectroscopy, Near-Infrared , Temperature , Thermodynamics
14.
Dent Mater ; 19(6): 458-65, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12837392

ABSTRACT

OBJECTIVE: Two visible light sources (tungsten-quartz-halogen and xenon-arc plasma) with vastly different intensities (200 and 1800 mW/cm(2)) but similar spectral outputs, were used to examine the effects of light intensity on conversion and flexural strength of a model dental resin formulation (75/25wt% bis-GMA/TEGDMA). METHODS: The exact same polymer samples were used to correlate double bond conversion (measured with near-IR spectroscopy) to flexural strength, both immediately after light exposure and after storage. RESULTS: In general, polymers which were irradiated with the high light intensity source exhibited greater double bond conversion. However, increasing the light intensity also increased the maximum temperature reached during polymerization. Therefore, the greater double bond conversion was caused by a combination of both photo and thermal effects. Regardless of the light intensity, a single linear relationship existed between conversion and final flexural strength (measured 4 days after cure) over the conversion range analyzed (50-80%). However, deviations from linearity were noted in several samples that were tested immediately after exposure. SIGNIFICANCE: These findings illustrate that light intensity does not affect the final flexural strength of a dental resin as long as the final conversions are similar.


Subject(s)
Composite Resins/chemistry , Composite Resins/radiation effects , Analysis of Variance , Bisphenol A-Glycidyl Methacrylate/chemistry , Bisphenol A-Glycidyl Methacrylate/radiation effects , Halogens , Light , Materials Testing , Molecular Structure , Pliability/radiation effects , Polyethylene Glycols/chemistry , Polyethylene Glycols/radiation effects , Polymers/chemistry , Polymethacrylic Acids/chemistry , Polymethacrylic Acids/radiation effects , Regression Analysis , Temperature , Xenon
15.
Am J Orthod Dentofacial Orthop ; 122(3): 242-50, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12226604

ABSTRACT

Light curing of composite resin material beneath orthodontic brackets is common in clinical orthodontics. Experiences with composite resins and high-intensity lights indicate some advantages to staged curing of the composite. In this study, the shear/peel bond strength of orthodontic brackets bonded to bovine enamel and cured with a pulsed xenon plasma arc light was compared with that of bonds cured with a conventional tungsten-quartz-halogen light and a nonpulsed xenon plasma arc light. The pulsed light provided less light energy than the nonpulsed lights. A small and a larger light-guide tip were used with the pulsed xenon plasma arc light. Three different orthodontic composite resin adhesives were tested with each light. The pulsed xenon plasma arc light resulted in either the same or decreased shear/peel bond strength when compared with the nonpulsed lights. There appeared to be no advantage to the use of a pulsed xenon plasma arc light in bonding orthodontic brackets. Results from using either a small or a large light-guide tip varied with the adhesive tested.


Subject(s)
Composite Resins/chemistry , Dental Bonding , Lighting/instrumentation , Orthodontic Brackets , Resin Cements/chemistry , Acid Etching, Dental , Acrylic Resins/chemistry , Analysis of Variance , Animals , Bisphenol A-Glycidyl Methacrylate/chemistry , Cattle , Dental Enamel/ultrastructure , Equipment Design , Halogens , Quartz , Spectrophotometry , Statistics as Topic , Statistics, Nonparametric , Stress, Mechanical , Surface Properties , Time Factors , Tungsten , Xenon
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