Effect of infection control barrier thickness on light curing units / 대한치과보존학회지

OBJECTIVES: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. MATERIALS AND METHODS: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eight-fold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. RESULTS: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). CONCLUSIONS: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

Necessity for a Whole-body CT Scan in Alert Blunt Multiple Trauma Patients

PURPOSE: Whole-body CT is a very attractive diagnostic tool to clinicians, especially, in trauma. It is generally accepted that trauma patients who are not alert require whole-body CT. However, in alert trauma patients, the usefulness is questionable. METHODS: This study was a retrospective review of the medical records of 146 patients with blunt multiple trauma who underwent whole body CT scanning for a trauma workup from March 1, 2008 to February 28, 2009. We classified the patients into two groups by patients' mental status (alert group: 110 patients, not-alert group: 36 patients). In the alert group, we compared the patients' evidence of injury (present illness, physical examination, neurological examination) with the CT findings. RESULTS: One hundred forty six(146) patients underwent whole-body CT. The mean age was 44.6+/-18.9 years. One hundred four (104, 71.2%) were men, and the injury severity score was 14.0+/-10.38. In the not-alert group, the ratios of abnormal CT findings were relatively high: head 23/36(63.9%), neck 3/6(50.0%), chest 16/36(44.4%) and abdomen 9/36(25%). In the alert group, patients with no evidence of injury were rare (head 1, chest 6 and abdomen 2). Nine(9) patients did not need any intervention or surgery. CONCLUSION: Whole-body CT has various disadvantages, such as radiation, contrast induced nephropathy and high medical costs. In multiple trauma patients, if they are alert and have no evidence of injury, they rarely have abnormal CT findings, and mostly do not need invasive treatment. Therefore, we should be cautious in performing whole-body CT in alert multiple trauma patients.

A case report of implant placement in distraction-augmented alveolar bone of the mandible

Microleakage of endodontic temporary restorative materials under dynamic loading / 대한치과보존학회지

The purpose of this study was to compare the sealing abilities of four endodontic temporary restorative materials using a methylene blue dye penetration test under dynamic loading. Standardized access cavities were prepared in forty-four intact human permanent molar teeth, and the cavities were restored with Caviton, MD-Temp, IRM, or ZOE. After thermocycling, an intermittent load of 98 N at 1 Hz was applied for 1,000 cycles to the long axis of the functional cusp of each of the teeth, which were immersed in a 1% methylene blue solution. The teeth were split in half, and the linear depth of dye penetration was evaluated according to the criteria. The results were analyzed using one-way ANOVA (p = 0.05) and Duncan's multiple range test. The results demonstrated that Caviton and MD-Temp showed significantly lower microleakage than IRM and ZOE. It was concluded that Caviton and MD-Temp exhibited better sealing ability than IRM and ZOE under dynamic loading.

Evaluation of the radiopacity and cytotoxicity of resinous root canal sealers / 대한치과보존학회지

The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.

A Comparison of the Efficacy of Cataract Surgery Using Aqualase(R) with Phacoemulsification Using MicroFlow(R) System

PURPOSE: To compare the outcomes after phacoemulsification performed with the AquaLase(R) and phacoemulsification in MicroFlow(R) system, including surgically induced astigmatism (SIA), corneal endothelial cell damage and postoperative recovery of visual acuity. METHODS: The cataracts of Lens Opacities Classification System, version III (LOCS III) nuclear grade below 2 were subjected in this study. Nineteen eyes underwent cataract operation using AquaLase(R) (Alcon Laboratories, Fort Worth, Texas, U.S.A.). A control group (19 eyes) used the MicroFlow(R) system (Millenium, Stortz, U.S.A.) and was selected by matching age, sex, systemic disease, corneal astigmatism and corneal endothelial cell density. All the surgeries were performed by the same operator. SIA, corneal endothelial cell loss, visual acuity, and corneal thickness were evaluated postoperatively. RESULTS: SIA in the group using AquaLase(R) was less than that of the group using MicroFlow(R) system (P=0.022) at 2 months postoperatively. Evaluation of corneal endothelial cell loss, recovery of visual acuity and corneal thickness found no statistically significant differences between the two groups. CONCLUSIONS: Cataract surgery using AquaLase(R) induces less surgically induced astigmatism in mild to moderate cataracts.

The palato-gingival groove - anatomical anomaly occurred in maxillary lateral incisors: case reports / 대한치과보존학회지

This report describes clinical cases of a palato-gingival groove on a maxillary lateral incisor with associated localized periodontal disease and pulp necrosis. The tooth of the first case was extracted because of severe bone destruction. The palato-gingival groove of the second case was eliminated using a round bur, and the resulting defect was filled with synthetic graft and covered by an absorbable membrane. Both diagnosis and treatment of palato-gingival groove were very difficult and usually extraction of the involved tooth is the treatment of choice, but combined endodontic-periodontic treatment allowed the tooth to be saved.

Comparison of A-scan, Scheimpflug Camera, and Orbscan for Measurement of Anterior Chamber Depth

PURPOSE: To assess the reproducibility and reliability of the A-scan, Scheimpflug camera and Orbscan Topography system in measuring anterior chamber depth (ACD) METHODS: In this prospective study of 207 eyes of 150 patients, ACD estimation prior to cataract surgery was done by three METHODS: A-scan, Scheimpflug camera, and Orbscan (in that order). One observer performed all measurements three times for each test. ACD was defined as the length between the center of anteror surface of cornea and the center of anterior lens surface. RESULTS: The mean ACD by the three methods were 2.86+/-0.46 mm, 3.22+/-0.46 mm, and 3.13+/-0.44 mm, respectively: the differences were statistically significant (P<0.01). The correlation coefficient between Scheimpflug camera and Orbscan was 0.93. The coefficient of variation for the three methods were 3.20% in the A-scan, 1.34% in the Scheimpflug camera, and 0.84% with Orbscan. CONCLUSIONS: Applanation A-scan gives lower measurements for ACD compared with Scheimpflug and Orbscan. There was good agreement between results obtained with the latter 2 methods based on optical principles. Orbscan had the best reproducibility of results among the three methods.

Evaluation of Accommodating Potency of the Accommodative Intraocular Lens by Change of Anterior Chamber Depth

PURPOSE: To investigate the accommodating potency of the 1CU accommodative posterior chamber intraocular lens (PC IOL), according to pilocarpine-induced ciliary muscle contraction, near visual acuity, and distance-corrected near visual acuity after implantation of the IOL. METHODS: In a prospective study, 9 eyes of 7 patients (mean age 48+/-14.9 years [range 23 to 71 years]) had phacoemulsification and PC IOL (1CU(R), Humanoptics). Distance refraction, distance visual acuity (VA), distance-corrected VA (DCVA), near visual acuity (NVA), and distance-corrected near visual acuity (DCNVA) were determined at 2 week, 1, 2, 6, and 12 months after surgery. Anterior chamber depth (ACD) was measured 3 times with the Orbscan(R) (Orbtek, U.S.A.), and averaged. Then ACD was repeatedly measured within 90 minutes after administration of pilocarpine 2% eyedrops 3 times at 10 minutes interval. RESULTS At 2 weeks, 1, 2, 6 and 12 months after surgery, the mean DCNVA was 0.55+/-0.23, 0.37+/-0.14, 0.40+/-0.22, 0.51+/-0.20, and 0.56+/-0.20, respectively. The mean ACD decrease (mm) was 0.57+/-0.77, 0.91+/-0.69, 0.17+/-0.45, 0.35+/-0.40 and 0.59+/-0.31, respectively, using Orbscan(R) after pilocarpine 2% eyedrops. There was statistically significant correlation between the pilocarpine-induced IOL movement and DCNVA (r=0.439, P=0.012). CONCLUSIONS: 1CU accommodative PC IOL provided relatively good DCNVA and accommodating potency for up to 1 year. It is necessary to investigate accommodative change for a longer time period.

Evaluation of Accommodating Potency of the Accommodative Intraocular Lens by Change of Anterior Chamber Depth

PURPOSE: To investigate the accommodating potency of the 1CU accommodative posterior chamber intraocular lens (PC IOL), according to pilocarpine-induced ciliary muscle contraction, near visual acuity, and distance-corrected near visual acuity after implantation of the IOL. METHODS: In a prospective study, 9 eyes of 7 patients (mean age 48+/-14.9 years [range 23 to 71 years]) had phacoemulsification and PC IOL (1CU(R), Humanoptics). Distance refraction, distance visual acuity (VA), distance-corrected VA (DCVA), near visual acuity (NVA), and distance-corrected near visual acuity (DCNVA) were determined at 2 week, 1, 2, 6, and 12 months after surgery. Anterior chamber depth (ACD) was measured 3 times with the Orbscan(R) (Orbtek, U.S.A.), and averaged. Then ACD was repeatedly measured within 90 minutes after administration of pilocarpine 2% eyedrops 3 times at 10 minutes interval. RESULTS At 2 weeks, 1, 2, 6 and 12 months after surgery, the mean DCNVA was 0.55+/-0.23, 0.37+/-0.14, 0.40+/-0.22, 0.51+/-0.20, and 0.56+/-0.20, respectively. The mean ACD decrease (mm) was 0.57+/-0.77, 0.91+/-0.69, 0.17+/-0.45, 0.35+/-0.40 and 0.59+/-0.31, respectively, using Orbscan(R) after pilocarpine 2% eyedrops. There was statistically significant correlation between the pilocarpine-induced IOL movement and DCNVA (r=0.439, P=0.012). CONCLUSIONS: 1CU accommodative PC IOL provided relatively good DCNVA and accommodating potency for up to 1 year. It is necessary to investigate accommodative change for a longer time period.