Efficacy of the Mineral Oil and Hyaluronic Acid Mixture Eye Drops in Murine Dry Eye

PURPOSE: To investigate the therapeutic effects of mineral oil (MO) and hyaluronic acid (HA) mixture eye drops on the tear film and ocular surface in a mouse model of experimental dry eye (EDE). METHODS: Eye drops consisting of 0.1% HA alone or mixed with 0.1%, 0.5%, or 5.0% MO were applied to desiccating stress-induced murine dry eyes. Tear volume, corneal irregularity score, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured at 5 and 10 days after treatment. Ten days after treatment, goblet cells in the conjunctiva were counted after Periodic acid-Schiff staining. RESULTS: There was no significant difference in the tear volume between desiccating stress-induced groups. The corneal irregularity score was lower in the 0.5% MO group compared with the EDE and HA groups. The 0.5% and 5.0% MO groups showed a significant improvement in TBUT compared with the EDE group. Mice treated with 0.1% and 0.5% MO mixture eye drops showed a significant improvement in fluorescein staining scores compared with the EDE group and the HA group. The conjunctival goblet cell count was higher in the 0.5% MO group compared with the EDE group and HA group. CONCLUSIONS: The MO and HA mixture eye drops had a beneficial effect on the tear films and ocular surface of murine dry eye. The application of 0.5% MO and 0.1% HA mixture eye drops could improve corneal irregularity, the corneal fluorescein staining score, and conjunctival goblet cell count compared with 0.1% HA eye drops in the treatment of EDE.

The Study of Ocular Side Effects after the Use of Anti-Glaucoma Topical Medication

PURPOSE: To investigate the influence of number and type of side effects as well as treatment period after the use of anti-glaucoma eye drops in patients with glaucoma. METHODS: A survey was conducted regarding the severity of ocular side effects after the use of anti-glaucoma eye drops in 528 patients with glaucoma. Side effects after using the eye drops included irritability, blurred vision, foreign body sensation, hyperemia, pinpricking sensation, itching, discomfort, pain, tearing, dry eye, and pigmentation. We analyzed the results to investigate the influence of number and type of side effects as well as treatment period. RESULTS: The side effects after the use of anti-glaucoma eye drops were more severe and frequent in the patient groups using more than 1 eye drop (p < 0.01) and in the patients with longer treatment period (p < 0.01). Among patients using 1 eye drops, side effects developed frequently in patients using Ocucarpine(R). CONCLUSIONS: In patients with glaucoma, using more than 1 anti-glaucoma eye drop or having a longer treatment period resulted in more side effects. Similaryly, patients using only 1 eye drop of Ocu-carpine(R) induced more side effects.

Long-Term Results after Cataract Surgery in Patients with Low Corneal Endothelial Cell Density

PURPOSE: To investigate the long-term results after cataract surgery in eyes with low endothelial cell density (ECD). METHODS: A retrospective medical record review was performed of 19 patients with low ECD (lower than 1000 cells/mm2) who 31 patients with a normal ECD (higher than 1600 cells/mm2) underwent cataract surgery. Clinical parameters including visual acuity, intraocular pressure (IOP), spherical equivalent refraction, anterior chamber depth, axial length and central corneal thickness (CCT) were measured and specular microscopy was performed to analyze the ECD and its morphology. The follow-up periods were 1 week, and 1, 3, 6 and 12 months postoperatively. RESULTS: Clinical parameters except ECD and CCT had no significant difference between the 2 groups until 12 months postoperatively. The decreasing rate of ECD and increase of CCT were significantly different between the 2 groups at 1 week and 1 month postoperatively. However, no significant difference was found after 3 months postoperatively. Only 1 eye in the low ECD group with 367 cells/mm2 developed bullous keratopathy. CONCLUSIONS: In the low ECD group, a significant decrease of ECD and increase of CCT were observed at 1 month after cataract surgery. However there were no significant differences compared with the control group after 3 months postoperatively. The results suggest that cataract surgery is safe postoperatively for a long-term for a patient with low ECD.

Effect of Combined Treatment with Cyclosporine A and Cord Serum for Dry Eye Associated with Graft-Versus-Host-Disease

PURPOSE: To investigate the efficacy of combined treatment with 0.05% cyclosporine A and 20% umbilical cord serum eye drops for severe dry eye associated with graft-versus-host disease (GVHD). METHODS: Eighteen patients with severe dry eye associated with GVHD were treated with 0.05% cyclosporine A and 20% umbilical cord serum eye drops (group 1, n = 16), 0.05% cyclosporine A eye drops (group 2, n = 10) or artificial tears only (group 3, n = 10). Tear film break up time (BUT), Schirmer test, tear clearance rate (TCR), and keratoepithelio pathy score were measured before and 1, 3 and 6 months after treatment. RESULTS: In group 1, significant improvement was observed in tear film BUT (from 3.25 +/- 1.18 s to 6.63 +/- 0.96 s, p < 0.01), TCR (from 2.38 +/- 0.72 to 3.13 +/- 0.72, p < 0.01) and keratoepithelio pathy score (from 6.31 +/- 2.15 to 0.88 +/- 0.89, p < 0.01) 6 months after treatment. Compared with group 2 and group 3, group 1 showed significant improvement in BUT (3 and 6 months after treatment) and keratoepitheliopathy score (1, 3 and 6 months after treatment). CONCLUSIONS: Combined treatment with 0.05% cyclosporine A and 20% umbilical cord serum eye drops is effective for severe dry eye associated with GVHD.

The effects of polishing technique and brushing on the surface roughness of acrylic resin / 대한치과보철학회지

PURPOSE: This study evaluated the effect of polishing techniques on surface roughness of polymethyl methacrylate (PMMA), as well as the influence of light-cured surface glaze and subsequent brushing on surface roughness. MATERIALS AND METHODS: A total of 60 PMMA specimens (10x10x5 mm) were made and then divided into 6 groups of 10 each according to the polymerization methods (under pressure or atmosphere) and the surface polishing methods (mechanical or chemical polishing) including 2 control groups. The mechanical polishing was performed with the carbide denture bur, rubber points and then pumice and lathe wheel. The chemical polishing was performed by applying a light-cured surface glaze (Plaquit(R); Dreve-Dentamid GmbH). Accura 2000(R), a non-contact, non-destructive, optical 3-dimensional surface analysis system, was used to measure the surface roughness (Ra) and 3-dimensional images were acquired. The surface roughness was again measured after ultrasonic tooth brushing in order to evaluate the influence of brushing on the surface roughness. The statistical analysis was performed with Mann-Whitney test and t-test using a 95% level of confidence. RESULTS: The chemically polished group showed a statistically lower mean surface roughness in comparison to the mechanically polished group (P = .0045) and the specimens polymerized under the atmospheric pressure presented a more significant difference (P = .0138). After brushing, all of the groups, except the mechanically polished group, presented rougher surfaces and showed no statistically significant differences between groups. CONCLUSION: Although the surface roughness increased after brushing, the chemical polishing technique presented an improved surface condition in comparison to the mechanical polishing technique.

Detorque values of abutment screws in a multiple implant-supported prosthesis / 대한치과보철학회지

PURPOSE: This study evaluated the detorque values of screws in a multiple implant-supported superstructure using stone casts made with 2 different impression techniques. MATERIAL AND METHODS: A fully edentulous mandibular master model and a metal framework directly connected to four implants (Branemark System(R); Nobel Biocare AB) with a passive fit to each other were fabricated. Six experimental stone casts (Group 1) were made with 6 non-splinted impressions on a master cast and another 6 experimental casts (Group 2) were made with 6 acrylic resin splinted impressions. The detorque values of screws (TorqTite(R) GoldAdapt Abutment Screw; Nobel Biocare AB) were measured twice after the metal framework was fastened onto each experimental stone cast with 20 Ncm torque. Detorque values were analyzed using the mixed model with the fixed effect of screw and reading and the random effect of model for the repeated measured data at a .05 level of significance. RESULTS: The mean detorque values were 7.9 Ncm (Group 1) and 8.1 Ncm (Group 2), and the mean of minimum detorque values were 6.1 Ncm (Group 1) and 6.5 Ncm (Group 2). No statistically significant differences between 2 groups were found and no statistically significant differences among 4 screws were found for detorque values. No statistically significant differences between 2 groups were also found for minimum detorque values. CONCLUSION: In a multiple external hexagon implant-supported prosthesis, no significant differences between 2 groups were found for detorque values and for minimum detorque values. There seems to be no significant differences in screw joint stability between 2 stone cast groups made with 2 different impression techniques.

The effect of screw tightening techniques on the detorque value in internal connection implant superstructure / 대한치과보철학회지

PURPOSE: This study evaluated the effect of different screw tightening sequences and methods on detorque values in a well-fitting implant superstructure. MATERIAL AND METHODS: A fully edentulous mandibular master model and a metal framework directly connected to four parallel implants (Astra Tech) with a passive fit to each other were fabricated. Six stone casts were made with a splinted impression technique to represent a 'well-fitting' situation with the metal framework. Detorque values were measured twice after screw tightening using 20 Ncm. Detorque values and minimum detorque values for three screw tightening sequences (1-2-3-4, 2-4-3-1, and 2-3-1-4) and for two tightening methods (two-step and one-step) were analyzed using multi-way analysis of variance and two-way analysis of variance, respectively, at a .05 level of significance. RESULTS: The mean detorque values for screw tightening sequences ranged from 12.8 Ncm (2-4-3-1) to 13.1 Ncm (2-3-1-4), and for screw tightening methods were 13.1 Ncm (two-step) and 11.8 Ncm (one-step). The mean of mimimum detorque values for screw tightening sequences were 11.1 Ncm (1-2-3-4) and 11.2 Ncm (2-4-3-1 and 2-3-1-4), and for screw tightening methods were 11.2 Ncm (two-step) and 9.9 Ncm (one-step). No statistically significant differences among three screw tightening sequences were found for detorque values and for mimimum detorque values. But, statistically significant differences between two screw tightening methods were found for two values. Two-step screw tightening method showed higher detorque value (P = .0003) and higher minimum detorque value (P = .0035) than one-step method. CONCLUSION: Within the limitations of this study, the screw tightening sequence was not a critical factor for the detorque values in a well-fitting implant superstructure by the splinted impression technique. But, two-step screw tightening method showed greater detorque values than one-step method.

Accuracy of a proposed implant impression technique using abutments and metal framework

PURPOSE: This study compared the accuracy of an abutment-framework (A-F) taken with open tray impression technique combining cementon crown abutments, a metal framework and resin cement to closed tray and resin-splinted open tray impression techniques for the 3-implant definitive casts. The effect of angulation on the accuracy of these 3 techniques was also evaluated. MATERIAL AND METHODS: Three definitive casts, each with 3 linearly positioned implant analogs at relative angulations 0, 30, and 40 degrees, were fabricated with passively fitted corresponding reference frameworks. Ten impressions were made and poured, using each of the 3 techniques on each of the 3 definitive casts. To record the vertical gap between reference frameworks and analogs in duplicate casts, a light microscope with image processing was used. Data were analyzed by two-way analysis of variance and the Tukey test. RESULTS: The open tray techniques showed significantly smaller vertical gaps compare to closed tray technique (P .05). CONCLUSION: The accuracy of the A-F impression technique was superior to that of conventional techniques, and was not affected by the angulation of the implants.

The effects of hyaluronic acid gel on the healing of oral mucosa

PURPOSE: In spite of various advantages of hyaluronic acid in wound healing, there are few research about wound healing process and period in oral and maxillofacial surgery. So, We evaluated the effects of local application of hyaluronic acid gel on wound healing of the oral mucosa using this animal model. MATERIALS AND METHODS: Young adult New Zealand White rabbits, weighting between 2.5 and 3.0kg, were used. Almost uniform round ulcerscould be created on the gingival of the rabbits by chemical injury with acetic acid. In experimental group, hyaluronic acid gel was applied daily until the wounds healed and in control group, ulcer lesion was not any treatment. The lengths of ulcers were measured the longest and shortest axes of the ulcers and calculated the areas of ulcer. For histological examination, specimens were made, and observed under a light microscope. RESULTS: The results showed that the number of fibroblasts, new blood vessels and the epithelial thickness from experimental group was higher than from control group. Hyaluronic acid promoted proliferation of the fibroblast, keratinocytes isolated from gingival tissue of rabbits in vitro. Topical application of hyaluronic acid accelerated healing of ulcers created in rabbits. CONCLUSION: The hyaluronic acid may be effective for wound healing of oral mucosal lesions.

The effect of screw tightening sequence and tightening method on the detorque value in implant-supported superstructure / 대한치과보철학회지

STATEMENT OF PROBLEM: The screw detorque value is a measure of the preload remaining in the screw just before detorquing. PURPOSE: This study evaluated the effect of different screw tightening sequences and tightening methods on detorque values for a well-fitting implant superstructure. MATERIAL AND METHOD: An implant superstructure that connected directly to four implants (Astra Tech) was fabricated on a fully edentulous mandibular acrylic resin model. Six wellfitting dental stone casts were made with a pickup impression of the superstructure from the acrylic resin model. To evaluate the effect of three screw tightening sequences (1-2-3-4, 2-4-3-1, and 2-3-1-4) and two tightening methods (2-step and 1-step) on the stability of screw joint, the detorque values for a well-fitting implant superstructure were measured twice after screw tightening using 20 Ncm. Detorque values were analyzed using multi-way analysis of variance and two-way analysis of variance at a .05 level of significance. RESULTS: 1. The mean detorque values for three screw tightening sequences were 12.3 Ncm, 12.6 Ncm, and 12.0 Ncm, respectively. 2. The mean detorque values for two screw tightening methods were 12.0 Ncm, and 12.2 Ncm, respectively. 3. The mean of mimimum detorque values for three screw tightening sequences and for two tightening methods were 10.6 Ncm, 11.1 Ncm, 10.5 Ncm, and 9.8 Ncm, respectively. 4. No statistically significant differences among the variables of screw tightening sequence and tightening method were found (p>.05) for detorque values and for mimimum detorque values. CONCLUSION: Within the limitations of this study, the screw tightening sequence and tightening method did not have a significant effect on the detorque values for a well-fitting implant superstructure.

Evaluation of the accuracy of fixture-level impression technique for internal connection implant using clinical methods / 대한치과보철학회지

Statement of problem: Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression technique in internal connection implant system. Purpose: This study evaluated the accuracy of splinted fixture-level impression technique using clinical methods and the effect of internal hex on fit of superstructure in internal connection implant system (Astra Tech). Material and method: Two metal master frameworks made from two abutments (Cast-to Abutment ST) each for parallel and divergent conditions and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts were made with vinyl polysiloxane impressions from the master cast by acrylic resin splinted fixture-level impression technique. To evaluate the accuracy of impression technique, the fit of master frameworks for test models was evaluated using screw resistance test (SRT) and onescrew test. The results of SRT were recorded as SRT values from grade 1 to grade 5 by 1/4 turn. And to evaluate the effect of hex on fit of superstructure, the same tests were performed after removing hexes of master frameworks. Results: 1. There was only one case (2.5%) showing SRT value of test model below grade 2 in total before and after removing hexes of master frameworks. And, by removing hexes, SRT values decreased in only one test model (5%) and did not change in 17 test models (85%). 2. SRT values of the 1st screws were grade 2 in 80% of cases before, and grade 1 in 80% of cases after removing hexes. And, by removing hexes, SRT values decreased in 72.5% of cases. 3. SRT values of the 2nd screws were grade 3 in 85% of cases before, and grade 3 in 95% of cases after removing hexes. And, by removing hexes, SRT values did not change in 85% of cases. 4. There were only 2 cases regarded as acceptable fit by one-screw test, and SRT values of 2nd screws of both cases were grade 2. Conclusion: Within the limitations of this study, fixture-level impression of internal connection implant system is considered to obtain inaccurate working cast, even using acrylic resin splinted impression technique. And, it is considered to be unable to improve the fit to remove the hexes of implant restoration.

Comparative accuracy of the splinted and unsplinted impression methods for internal connection / 대한치과보철학회지

STATEMENT OF PROBLEM: Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression techniques in internal connection implant systems. PURPOSE: The purpose of this study was to compare the accuracy of two fixture-level impression techniques in two conditions (parallel and divergent) and to assess the effect of tightening sequences and forces on stresses generated on superstructures in internal connection implant system (Astra Tech). MATERIAL AND METHODS: Two metal master frameworks made from two abutments (Cast-to Abutment ST) each and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts for each impression techniques (direct unsplinted and splinted technique) were made with vinyl polysiloxane impressions from the master cast. Strain gauges for each framework were fixed midway between abutments to measure the degree of framework deformation on each stone cast. Pairs of strain gauges placed opposite each other constituted one channel (half Wheatstone bridge) to read deformation in four directions (superior, inferior, anterior, and posterior). Deformation data were analyzed using one-way ANOVA and the Tukey test at the .01 level of significance. And the effect of tightening sequences (right-to-left and left-to-right) and forces (10 Ncm and 20 Ncm) were assessed with ten stone casts made from parallel condition by the splinted technique. Deformation data were analyzed using paired t-test at the .01 level of significance. CONCLUSIONS: Within the limitations of this study, the following conclusions could be drawn. 1. Frameworks bent toward the inferior side on all casts made by both direct unsplinted and splinted impression techniques in both parallel and divergent conditions. 2. There was no statistically significant difference of accuracy between the direct unsplinted and splinted impression techniques in both parallel and divergent conditions (P>.01). 3. There was no statistically significant difference of stress according to screw tightening sequences in casts made by the splinted impression technique in parallel condition (P>.01). 4. Greater tightening force resulted in greater stress in casts made by the splinted impression technique in parallel condition (P<.01).