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OBJECTIVE: To see whether there is an advantage to using a self-limiting phosphoric acid etchant versus a traditional 34% phosphoric acid etchant for bonding by measuring the depth of etch at multiple time intervals. MATERIALS AND METHODS: A total of 25 bovine teeth were mounted and etched on the facial surface with two different etchants: standard 34% phosphoric acid and a self-limiting 35% phosphoric acid etchant at varied time intervals of 15, 30, 60, 90, and 120 seconds. Teeth were scanned using a three-dimensional laser confocal scanning microscope prior to etching and scanned again after etching to determine the depth of enamel etched compared to the baseline enamel surface prior to etching. RESULTS: The 34% phosphoric acid etchant etched significantly deeper than the self-limiting etch. Etch times exceeding 30 seconds also etched significantly deeper for both types of etchant. CONCLUSION: The etch depth of the self-limiting etchant was consistently less than the standard etchant. Both types of etchant etched deeper after 30 seconds, but the depth of etch at 120 seconds was not different than at 60 seconds, indicating that both etchants are somewhat self-limiting in depth. Therefore, there is no advantage to using the self-limiting etchant.

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Sonication technology has recently been touted to decrease composite viscosity during delivery and may allow better cavity preparation adaptation and minimize voids. The purpose of this investigation was to evaluate the difference between conventional, hand-placed, incremental application of a standard hybrid resin-based composite (RBC) and sonicated application of a bulk-fill RBC in box-type and cylindrical cavity preparations. Experimental restorations were fabricated using molds of box-type or cylindrical preparations. For bulk-filled specimens, a single compule of bulk-fill composite was dispensed with a sonic handpiece. The conventional hybrid material was placed in 3 increments (2 mm, 2 mm, and 1 mm). Microfocus x-ray computed tomography was used to analyze voids for percentage and total volume porosity as well as number of actual pores. An analysis of variance indicated that RBC restorations that were applied to cylindrical cavities using a sonicated bulk-filled application method exhibited significantly less porosity (1.42%; P < 0.001) than incrementally placed cylindrical restorations (2.87%); sonicated bulk-filled, cube-shaped restorations (3.12%); and incrementally placed cube-shaped restorations (5.16%). When the groups were subcategorized into the specific characteristics of shape (cube vs cylinder) and application method (bulk vs incremental), the cylindrical group, which included both bulk-filled and incrementally placed specimens, demonstrated significantly less porosity (2.00%; P < 0.001) than other groups. Restorations that were incrementally placed into cube-shaped cavities produced the largest amount of porosity.

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OBJECTIVE: To investigate the relationship between a micropulse vibration device and pain perception during orthodontic treatment. MATERIALS AND METHODS: This study was a parallel group, randomized clinical trial. A total of 58 patients meeting eligibility criteria were assigned using block allocation to one of two groups: an experimental group using the vibration device or a control group (n  =  29 for each group). Patients used the device for 20 minutes daily. Patients rated pain intensity on a visual analog scale at appropriate intervals during the weeks after the separator or archwire appointment. Data were analyzed using repeated measures analysis of variance at α  =  .05. RESULTS: During the 4-month test period, significant differences between the micropulse vibration device group and the control group for overall pain (P  =  .002) and biting pain (P  =  .003) were identified. The authors observed that perceived pain was highest at the beginning of the month, following archwire adjustment. CONCLUSION: The micropulse vibration device significantly lowered the pain scores for overall pain and biting pain during the 4-month study period.

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BACKGROUND: Bisphenol A (BPA) and other related chemical compounds may be components used in the manufacturing process of resin-based composite dental restorative material. The purpose of the authors' study was to assess salivary and urinary concentrations of BPA and other compounds before and after placement of resin-based composite dental restorations. METHODS: The authors collected saliva and urine from 172 participants receiving composite restorations before and as long as 30 hours after placement of composite restorations. The authors analyzed saliva specimens from 151 participants and urine specimens from 171 participants for concentrations of BPA and five related compounds by using liquid chromatography/mass spectrometry (LC/MS). RESULTS: Salivary concentrations of BPA and some related compounds increased immediately (within one hour) after composite placement. Salivary concentrations of BPA and most study compounds returned to prerestoration levels within eight hours after composite placement. With the exception of a 43 percent increase in BPA, concentrations of the study compounds in urine returned to prerestoration levels nine to 30 hours after restoration placement. Concentrations in saliva were lower when a rubber dam was used; however, rubber dam use appeared to have no effect on urinary concentrations of the measured compounds during the study period. The authors observed similar changes in study compound levels in both saliva and urine between participants who received anterior restorations and those who received posterior restorations. CONCLUSIONS: Placement of resin-based composite restorations was associated with detectable increases in saliva of BPA and other study compounds within one hour after restoration placement and an increased concentration of BPA in urine nine to 30 hours after restoration placement. Rubber dam use did not reduce the absorption of BPA (measured as BPA level in urine) during the study. CLINICAL IMPLICATIONS: Additional studies are needed to address how long BPA levels in urine associated with composite placement remain elevated to aid in better understanding of the clearance rates of BPA and other study compounds.

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Aryl substituted tropanes and their 2,3-ene analogs are highly selective inhibitors of monoamine uptake. The solution structures of a series of aryl tropanes were determined using NMR spectroscopy and molecular modeling to identify conformational preferences that may determine the overall activity. The majority of these analogs undergo nitrogen inversion, and the rate of interconversion between the axial and equatorial N-methyl conformers is fast on the NMR timescale at room temperature but slow between 217 and 243 K allowing us to determine the thermodynamic parameters of interconversion using dynamic and magnetization transfer NMR. The biological activities correlate strongly with the nature and the orientation of the aryl group. The relative orientation of the N-methyl further modulates the activity by directly influencing the ligand interaction in the protein binding pocket and/or by forcing a favorable orientation for the aryl substituent to fit in the binding pocket.

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Dental emergencies can significantly affect the mission of the deployed unit. As many as 22% of all emergency department visits at a deployed Expeditionary Medical Support facility can be attributed to dental problems and many of these problems are caused by impacted third molar teeth. Currently, there is no reliable method of predicting when asymptomatic, partially erupted third molar teeth will become painful. Therefore, it is imperative that Air Force dental providers carefully consider the consequences of giving patients a clean bill of health when asymptomatic, partially erupted third molar teeth are present in the oral cavity. Recommendations for future study are presented.

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OBJECTIVE: The purpose of this in vitro study was to investigate the effect of isopropyl alcohol and unfilled resin on the flexural strength of incrementally layered resin-based composite beams. METHOD AND MATERIALS: Five groups of 30 composite beams were fabricated in a 2 3 2 3 24-mm Teflon split-mold: group 1 (control group), a homogeneous resin composite beam; group 2, 2 increments with an air-inhibited layer between the increments; group 3, 2 increments with a Mylar strip placed against the composite interface during polymerization of the first increment; group 4, 2 increments with the first increment contoured with an isopropyl alcohol (70%) lubricated instrument; and group 5, 2 increments with the first increment contoured with unfilled resin lubricating the application instrument. Each increment was polymerized for 40 seconds on both front and back surfaces. The flexural strength of the composite specimens was determined using 4-point bending in an Instron universal testing machine. RESULTS: The mean flexural strength in MPa and standard deviation were as follows: group 1: 142.5 (17.3); group 2: 98.2 (15.2); group 3: 105.9 (16.3); group 4: 103.4 (19.4); and group 5: 106.1 (21.3). One-way analysis of variance detected a statistically significant difference among the groups (P < .001). Tukey's HSD post hoc tests determined that only group 1 was significantly different from the other 4 groups. CONCLUSION: The use of isopropyl alcohol and unfilled resin as instrument lubricants for incremental composite buildup seems to have little effect on the flexural strength of light-cured composite.

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The purpose of this investigation was to evaluate the reduction in perceived pain in patients with myofascial pain (MFP) using a group cognitive behavior therapy (CBT) course. Twenty-six participants diagnosed as having MFP were enrolled. Each CBT session had a small-group format, where participants received instruction in habit reversal, stress management, and progressive relaxation. Participants served as their own control subjects and were surveyed for pain intensity, duration, and frequency at study enrollment, before attending the CBT course, and 2 to 3 weeks after course completion. Wilcoxon signed-rank tests revealed that changes in intensity, frequency, and duration were significant (p < 0.001 to p < 0.045). Thirty-three percent of the participants showed improvement with home care instructions before CBT course start, whereas 65% of the participants showed improvement after the CBT course. Participants attending CBT group training exhibited significant improvements in MFP intensity, frequency, and duration, compared with levels reported at the initial evaluation.

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INTRODUCTION: Amorphous calcium phosphate (ACP) materials have recently been introduced with the promise of reducing demineralization around orthodontic brackets. The purpose of this in vitro study was to compare the shear bond strength of orthodontic brackets bonded with enamel using a commercially available orthodontic adhesive containing ACP to that of brackets bonded with a conventional resin-based orthodontic adhesive. METHODS: Thirty extracted molars were collected. The first group of 30 brackets was bonded to either the mesiobuccal or distobuccal tooth surface with a conventional resin-based composite adhesive. The second group of 30 brackets was bonded with the ACP adhesive to the buccal cusp that was not used by the first group. Each tooth received 2 brackets; 1 bonded with a conventional resin-based composite adhesive and the other with the ACP-containing orthodontic adhesive. Specimens were stored in water at 37 degrees C for 24 hours and then tested for shear bond strength in an Instron universal testing machine. A paired t-test was used to compare the mean shear bond strength between the 2 adhesives. The ARI scores were analyzed using the chi-squared test. All statistical tests were performed at alpha =.05. RESULTS: The t-test detected a highly significant difference in the mean shear bond strength between the 2 groups (P <.001). There was no evidence to suggest a statistical difference between the groups' ARI scores (P = .37). CONCLUSIONS: Under the conditions of this in vitro study, orthodontic brackets bonded to teeth with an ACP-containing composite material failed at significantly lower forces than brackets bonded to teeth with the conventional resin-based composite orthodontic cement.

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INTRODUCTION: The purpose of this in-vitro study was to compare the torsional stability of split crimpable surgical hooks and soldered brass surgical hooks on a rectangular stabilizing archwire. METHODS: Coated split crimpable hooks (Never-Slip Grip, TP Orthodontics, LaPorte, Ind), ribbed crimpable hooks (TP Orthodontics), and .032-in brass soldered hooks/notched electrodes (Ormco/Sybron Dental Specialties, Orange, Calif) were attached to a 0.019 x 0.025-in stainless steel archwire. The archwire/hook attachment assembly was secured into a dual contact jig and statically mounted to the base of a universal testing machine. The hooks were engaged by a wire loop attached to the upper load cell of the machine, which pulled the wire until the hook was torsionally displaced from the archwire. RESULTS: The mean forces, measured in newtons (N), required to dislodge the hooks were as follows: soldered brass surgical hooks (51.3 +/- 5.2 N), coated split crimpable hooks (49.9 +/- 6.6 N), and ribbed split crimpable hooks (31.3 +/- 5.4 N). Data were analyzed with 1-way ANOVA and Tukey HSD post-hoc tests at alpha = .05. Ribbed split crimpable hooks provided significantly less resistance to torsional displacement than the other types of hooks (P <001). There was no difference between coated split crimpable hooks and soldered brass surgical hooks (P >05). CONCLUSIONS: Under the conditions of this study, the results suggest that soldered brass surgical hooks and coated split crimpable hook attachments provide more stability to torsional dislodgement from a rectangular stabilizing archwire than ribbed split crimpable hooks.

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INTRODUCTION: The purpose of this study was to evaluate the battery lives of cordless light-emitting diodes (LEDs) and their effect on orthodontic bracket bond strength. METHODS: One hundred eighty-six metal orthodontic brackets were bonded to extracted molars. Two LED light-curing units (L. E. Demetron [SDS/Kerr, Orange, Calif] and Ortholux [3M Unitek, Monrovia, Calif]) were evaluated. Each light was used to bond 93 specimens. One bracket was bonded every 5 minutes until the battery ran out. The lights were activated for 20 seconds, then automatically turned off for 40 seconds every minute (33% duty cycle) without recharging. Bonded specimens were stored in water at 37 degrees C for 24 hours and then subjected to shear force with a universal testing machine until bracket failure. RESULTS: Repeated measures ANOVA detected significantly weaker mean shear bond strength and fewer consecutive cures with the Ortholux compared with the L. E. Demetron light-curing unit. However, when the first 5 time points were excluded, there were no differences between the 2 lights, demonstrating that the lights performed similarly after the first 20 minutes of operation Just before battery failure, both lights still provided the same power density as at the beginning. CONCLUSIONS: Both light-curing units provided adequate power density for up to 2 hours without recharging at a 33% duty cycle. There was no significant decrease in power in cordless LED light-curing units as the battery life approached its end point.

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INTRODUCTION: The purpose of this in-vitro study was to compare the shear bond strength of orthodontic brackets bonded to tooth enamel with 4 adhesives: a commercially available giomer material, a polyacid-modified composite resin (PMCR), a resin-modified glass ionomer (RMGI), and a standard resin-based composite (RBC) adhesive. MATERIALS: Eighty extracted human molars were collected and divided into 4 groups (n = 20). Two stainless steel premolar brackets were bonded to each tooth with 1 of the 4 adhesives, according to each manufacturers' instructions. One bracket was tested for shear bond strength at 1 hour and the other at 7 days. A shear force was applied to the bracket/tooth interface with a chisel-shaped rod attached to a universal testing machine at a crosshead speed of 0.5-mm per minute until bracket failure. The force in newtons was recorded. Debonded enamel surfaces were examined under a stereomicroscope to assess the amount of residual adhesive. RESULTS: A 2-factor analysis of variance detected significant differences among adhesive types and time of load test. The Tukey HSD test determined that the RBC and the RMGI adhesives had significantly higher shear bond strength than the giomer and the PMCR materials at both 1 hour and 7 days. The chi-square test detected a significant difference in adhesive remnant index scores. The bracket/resin interface was the most common site of failure for all groups except the RMGI group. CONCLUSIONS: RMGI orthodontic cement provides acceptable bond strength in vitro. Further clinical research is needed to validate this laboratory finding.

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INTRODUCTION: Recent studies have suggested that a 10-second cure time with a high-energy quartz-tungsten-halogen (QTH) or a light-emitting diode (LED) light might be adequate when bonding orthodontic brackets to tooth enamel. The purpose of this study was to evaluate the ability of the latest generation of QTH and LED light-curing units (LCUs) to bond orthodontic brackets to teeth at decreased polymerization times. METHODS: Two LED LCUs (Ortholux LED, 3M Unitek, Monrovia, Calif; UltraLume LED 5, Ultradent Products, South Jordan, Utah) and a QTH LCU (Optilux 501, Demetron, Danbury, Conn) were evaluated. One hundred eighty metal orthodontic brackets were bonded to extracted human molars. The specimens were divided into 9 groups (3 lights and 3 curing times) of 20 teeth each. Each group was cured with 1 of the 3 lights for 20, 10, or 6 seconds. Thirty minutes after polymerization, the specimens were subjected to shear force on a universal testing machine until bracket failure. RESULTS: Two-way ANOVA detected significant differences among the main effects of light type and cure time. Tukey post-hoc tests determined that brackets bonded by all light types had lower bond strengths with the 6-second cure than the 20-second cure (P < .001). The highest bond strengths were obtained with the Optilux 501 QTH LCU and the UltraLume LED 5 LCU at the longest cure time of 20 seconds. CONCLUSIONS: It is recommended that orthodontic brackets be photopolymerized for at least 20 seconds with the QTH or the LED LCU before the archwires are engaged.

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Scurvy is a nondiscriminatory disease process resulting from a nutritional deficiency of ascorbic acid (vitamin C). The severe vitamin deficiency produces a breakdown in the cellular structure of the body. This case report describes a middle-age woman with a history of edema, bruising of the lower extremities, anemia, and severe periodontal disease. Her presentation and medical history are classic for the signs of scurvy. Scurvy is now only uncommonly seen in developed countries, but there are still vulnerable populations whose nutritional status can lead to scurvy. The aim of this report is to help the clinician identify and treat scurvy, a disease that was once feared for its high mortality but is now easily treatable, even in cases that have progressed to multiple organ dysfunction and failure.

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PURPOSE: This study evaluated the effect of light dispersion of halogen and LED curing lights on resin composite polymerization. MATERIALS AND METHODS: One halogen (Optilux 501, SDS/Kerr, Orange, CA, USA) and five light-emitting diode (LED) curing lights (SmartLite iQ, Dentsply Caulk, Milford, DE, USA; LEDemetron 1, SDS/Kerr; FLASHlite 1001, Discus Dental, Culver City, CA, USA; UltraLume LED 5, Ultradent Products, South Jordan, UT, USA; Allegro, Den-Mat, Santa Maria, CA, USA) were used in this study. Specimens (8 mm diameter by 2 mm thick) were made in polytetrafluoroethylene molds using hybrid (Z100, 3M ESPE, St. Paul, MN, USA) and microfill (A110, 3M ESPE) composite resins. The top surface was polymerized for 5 seconds with the curing light guide tip positioned at a distance of 1 and 5 mm. Degree of conversion (DC) of the composite specimens was analyzed on the bottom surface using micro-Fourier Transform Infrared (FTIR) spectroscopy (Perkin-Elmer FTIR Spectrometer, Wellesley, PA, USA) 10 minutes after light activation. DC at the bottom of the 2 mm specimen was expressed as a percentage of the mean maximum DC. Five specimens were created per curing light and composite type (n=5). Percent mean DC ratios and SDs were calculated for each light under each testing condition. Data were analyzed by analysis of variance (ANOVA)/Tukey's test (alpha = .05). A beam analyzer (LBA-700, Spiricon, Logan, UT, USA) was used to record the emitted light from the curing lights at 0 and 5 mm distances (n=5). A Top Hat factor was used to compare the quality of the emitted beam profile (LBA/PC, Spiricon). The divergence angle from vertical was also determined in the x- and y-axes (LBA/PC). Mean values and SDs were calculated for each light under each testing condition (0 and 5 mm, x- and y-axes) and analyzed by a two-way ANOVA/Tukey's test (alpha = .05). RESULTS: For DC ratios, significant differences were found based on curing light and curing distance (p < .05). At 1 mm, Optilux 501 and FLASHlite 1001 produced significantly higher DC ratios with the hybrid resin composite. No differences were found among lights with the microfill at 1 mm. At 5 mm, SmartLite iQ, FLASHlite 1001, LEDemetron 1, and UltraLume LED 5 produced significantly higher DC ratios with the hybrid resin composite, whereas LEDemetron 1 and SmartLite iQ produced significantly higher DC ratios with the microfill resin composite. The UltraLume LED 5, Allegro, and Optilux 501 had significant reductions in mean DC ratios at curing distances of 1 and 5 mm with both resin composite types. For dispersion of light, significant differences were found in Top Hat factor and divergence angle (p < .001). SmartLite iQ had overall the highest Top Hat factor and lowest divergence angle of tested lights. A linear regression analysis relating pooled DC with pooled Top Hat factors and divergence angles found a very good correlation (r2 = .86) between dispersion of light over distance and the ability to polymerize resin composite. CLINICAL SIGNIFICANCE: The latest generation of LED curing lights provides DC ratios similar to or better than the halogen curing light at a curing distance of 5 mm. Dispersion of light plays a significant role in the DC of resin composite. To maximize curing effectiveness, light guides should be maintained in close proximity to the surface of the light-activated restorative material.

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A series of new 3-aryl-tropanes have been synthesized, and their affinities and selectivities were evaluated for monoamine transporters. (1RS)-3-(Fluoren-2-yl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene exhibited the highest affinity for the human serotonin transporter (IC(50)=14.5nM). It is also 52-fold and 230-fold selective over human dopamine and norepinephrine transporters, respectively.

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A quick, failsafe method for the esthetic replacement of a catastrophically fractured anterior tooth was presented. This method required minimal armamentarium and no anesthesia. In addition, it employed a technique that is not technique sensitive. The patient and the dental team both benefit by resolving the esthetic crisis using simple methods and excellent time resource management.

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