Decreased catalase expression and increased susceptibility to oxidative stress in primary cultured corneal fibroblasts from patients with granular corneal dystrophy type II.

Granular corneal dystrophy type II (GCD II) is an autosomal dominant disorder characterized by age-dependent progressive accumulation of transforming growth factor-beta-induced protein (TGFBIp) deposits in the corneal stroma. Several studies have suggested that corneal fibroblasts may decline with age in response to oxidative stress. To investigate whether oxidative stress is involved in the pathogenesis of GCD II, we assayed antioxidant enzymes, oxidative damage, and susceptibility to reactive oxygen species-induced cell death in primary cultured corneal fibroblasts (PCFs) from GCD II patients and healthy subjects. We found elevated protein levels of Mn-superoxide dismutase, Cu/Zn-superoxide dismutase, glutathione peroxidase, and glutathione reductase, as well as increased CAT mRNA and decreased catalase protein in GCD II PCFs. Furthermore, catalase is down-regulated in normal PCFs transfected with transforming growth factor-beta-induced gene-h3. We also observed an increase in not only intracellular reactive oxygen species and H(2)O(2) levels, but also malondialdehyde, 4-hydroxynonenal, and protein carbonyls levels in GCD II PCFs. Greater immunoreactivity for malondialdehyde was observed in the corneal tissue of GCD II patients. In addition, we observed a decrease in Bcl-2 and Bcl-xL levels and an increase in Bax and Bok levels in GCD II PCFs. Finally, GCD II PCFs are more susceptible to H(2)O(2)-induced cell death. Together, these results suggest that oxidative damage induced by decreased catalase is involved in GCD II pathogenesis, and antioxidant agents represent a possible treatment strategyope

Involvement of TGF-{beta} receptor- and integrin-mediated signaling pathways in the pathogenesis of granular corneal dystrophy II

Purpose. The purpose of this study was to elucidate the pathophysiological process in primary cultured corneal fibroblasts (PCFs) from normal subjects and granular corneal dystrophy (GCD) II patients, by using cDNA microarrays. Methods. PCFs were isolated from the corneas of normal subjects and GCD II patients who were heterozygous and homozygous for the TGFBI R124H mutation. RNA was isolated from each sample, and gene expression profiles were analyzed with a cDNA microarray consisting of approximately 29,000 genes. Cell adhesion assays were performed to confirm the functionality of the detected gene expression profiles. Results. Twofold differences were detected in the expression of 555 genes between wild-type and homozygous GCD II PCFs. Of these, 319 genes were upregulated, and 236 genes were downregulated in the homozygous GCD II PCFs. The most abundant and consistent changes were observed in gene families encoding signal transduction pathways involving the TGF-beta receptor- and integrin-mediated signaling, cell differentiation and proliferation, immune responses, cell adhesion, extracellular matrix (ECM) proteolytic enzymes, cell cycle, cytoskeletal organization, mitochondrial energy metabolism, collagen catabolism, response to wounding, response to oxidative stress, and the ubiquitin-mediated proteasomal degradation pathway. Cell adhesion assays demonstrated that heterozygous and homozygous GCD II PCFs strongly attached to collagen-I, collagen-IV, fibronectin, and laminin, compared with wild-type cells. Conclusions. Alterations in the TGF-beta receptor- and integrin-mediated signaling pathway may play a key role in GCD II pathophysiology. If the novel factors identified in this study are involved in GCD II pathogenesis, they could assist in designing further studies to elucidate specific mechanisms of this diseaseope

Characterization of dental pulp stem cells from deciduous and supernumerary teeth

치의학과/박사[영문]In recent year, there has been an increasing demand for tooth bleaching in order to improve the esthetic appearance of patients, because it is an easy, effective, and non-destructive treatment to remove these tooth discolorations. Hydrogen peroxide (HP) acts as a strong oxidizing agent through the formation of free radicals, reactive oxygen molecules, and HP anions. Current studies have presented contradictory results concerning the adverse effects of tooth bleaching agent on enamel surfaces. The purpose of this study was to evaluate the tooth whitening and properties of an enamel surface after treatments with tooth bleaching agents that contained dicalcium phosphate dihydrate and HP. DCPD (CaHPO4·2H2O) is known to be a precursor to hydroxyapatite (HA) in the remineralization process. Many studies have shown that supplemental calcium and phosphate in the form of DCPD have an anticaries benefit. In acidic solutions, DCPD was thermodynamically more stable than other calcium phosphates. This study selected 35 % HP and 3.5 % HP, which were used in-office bleaching and home bleaching agent. Sixty enamel specimens were obtained from human premolars and randomly divided into two groups. These groups were then divided into three subgroups (n=10). Tooth bleaching agents were prepared with DCPD (0 g for controls, 0.1 g and 1 g for experimental groups) and HP solution (35 % and 3.5 % HP). In the Group A, DCPD / 35 % HP solutions were applied on sectioned enamel surfaces for 60 min per day for 1 day. In the Group B, DCPD / 3.5 % HP solutions were applied on sectioned enamel surfaces for 8 hours per day for 14 days. pH and mineral composition (ICP-AES) in the tooth bleaching agent were measured. Tooth color, microhardness and surface characterization (SEM and EDX) of enamel surface were measured as well.1. The tooth bleaching agents with DCPD showed a significant increase in pH as compared with the ones without DCPD in the group A (p0.05). 2. As the concentration of DCPD was increased, the concentration of Ca and P was also increased. The ratio of Ca/P was found to be approximately 1.1 ~ 1.2. 3. In all groups, after the tooth whitening, the tooth color was found to have a value of L* which was significantly increased, while that of a* and b* were significantly decreased as compared with the ones that were seen prior to the tooth whitening (p<0.05). 4. In all groups, the hardness of tooth after bleaching showed a significant decrease in the microhardness as compared with the one prior to tooth bleaching (p<0.05). In both group A and B, however, as DCPD content was increased, the decreasing degree of microhardness was found to be smaller in the experimental group as compared with the control group.5. Following an analysis of the characteristics of enamel surface after bleaching, there were porosity and erosion in the control group. In the groups where the amount of DCPD was the greatest, however, there was no surface change. 6. Following an analysis of the constituents of enamel surface after bleaching, as DCPD content was increased, the amount of Ca and P was significantly increased (p<0.05). Based on the above results, tooth bleaching agents of 35 % and 3.5 % of HP containing DCPD are equally effective to the control group. By raising the pH and thereby effectively reducing the decalcification of tooth surface, a lower degree of the effects are given to the surface characteristics and constituent alterations of enamel. Thus, the commercial availability can be achieved for the constituents of tooth whitening materials.restrictio

(A) survey of sedation practices in the Korean pediatric dental office

치의학과/석사[한글] 진정요법은 소아치과에서 사용하는 보상, 속박, Tell-Show-Do, 친밀감 같은 통상의 방법으로는 환자의 반응이 개선되지 않아 일반적인 치과치료가 불가능할 때 사용하는 행동조절법이다. 최근 국내에서도 진정요법을 이용하는 사례가 증가하는 추세이나 그 기준이나 방법들에 대한 연구는 매우 부족한 상태이다. 미국소아치과학회의 진정요법에 관한 기준이 있기는 하지만 국내의 상황이 미국과 다르므로 한국에서의 연구가 필요하다. 이에 국내에 거주하고 있는 대한 소아치과학회 회원 573명을 대상으로 진정요법 사용 실태에 관한 설문지를 발송하여 이 중 회신을 한 220명의 설문을 분석하여 다음의 결과를 얻었다. 1. 응답자의 약 66%가 진정요법을 사용하고 있다고 답했다. 진정요법에 관한 이전 연구 결과와 비교해 볼 때, 국내 소아치과에서 진정요법의 사용빈도가 증가하였다. 2. 진정요법으로 치료를 결정하게 된 요인은 행동조절, 치료내용과 양, 보호자의 요구, 내원횟수, 전신질환의 순서이었다. 3. 진정요법으로 치료받는 환자의 연령은 만 3세가 가장 많았고, 만 4-5세, 만 2세 미만, 만 6-10세, 만 10세 이상의 순서로 조사되었다. 4. 진정요법 시 chloral hydrate는 60-70mg/kg, hydroxyzine은 10-40mg/kg/(25mg/kg)을 사용하고 있었고, 경구 투여가 가장 선호하는 약물투여 경로였다. 5. 진정요법 시 사용하는 환자감시 방법은 피부나 손톱색 등의 관찰을 포함한 환자 평가와 맥박 산소측정기(pulse oximeter)를 통한 환자감시를 선호하는 것으로 조사되었다. 6. 진정요법을 사용하고 있다고 응답한 사람의 약 56%에서 심폐소생술 교육을 받은 것으로 조사되었다. [영문]Sometimes the dentists encounter a child who can not be treated with traditional behavior management techniques (for example, reward, restraint, Tell-Show-Do, familialization). In such a case, the dentists use sedation technique. Recently, in Korea, the use of sedation by pediatric dentists is increased. But, the guideline and survey of sedation is very insufficient. Now, we need a survey of sedation practice in Korea. We carried out research on the actual condition about sedation with a questionaire to pediatric dentists in Korea. Followings are the conclusions 1. Sixty six percent of pediatric dentists use sedative agents in their practice. In this study, using sedation shows a increase as compared with the past. 2. Determinative factors of using sedation was orderly behavior management, number of visiting, guidian''s opinion, amount of treatment, general condition. 3. Distribution of ages in patients sedated with agents was orderly 3 years, 4-5 years, under 2 years, 6-10 years, more than 10 years. 4. Particular sedative drugs were chloral hydrate 60-70mg/kg, hydroxyzine 10-40mg/kg(25mg/kg), and oral route was the most favorable route. 5. Observation of skin and nail color, pulse oximeter were the most frequently utillized monitoring method during sedation. 6. Only fifty six percent of pediatric dentists complete the cardiopulmonary resuscitation course.ope

Kinematic Effects of Nickel-Titanium Instruments with Reciprocating or Continuous Rotation Motion: A Systematic Review of In Vitro Studies.

INTRODUCTION: This review aimed to compare the kinematic effect of nickel-titanium instruments with reciprocating and continuous rotation motion for cyclic fatigue resistance, shaping ability, apical debris extrusion, and dentinal defects or cracks. METHOD: Articles were selected for inclusion in this review if they fulfilled all of the following criteria: described in vitro studies performed on either extracted human teeth or an artificial canal model, assessed both reciprocating and rotary instruments, compared reciprocating files and rotary files for the kinematics of files, and evaluated reciprocating and rotary files regarding the aim of this study. The electronic search was undertaken in MEDLINE, Cochrane database, and manual searches, including journals, reference lists, and other reviews. RESULTS: Twelve studies were chosen for cyclic fatigue, 19 studies for shaping ability, 14 studies for apical debris extrusion, and 13 studies for dentinal defects or cracks. Most of the studies showed that reciprocating motion had a higher resistance to cyclic fatigue. Nine studies from the shaping studies reported less canal transportation by using the reciprocating motion than the continuous rotation. The reciprocating instruments tended to extrude more dentin debris than the continuous rotating instruments, but many of the studies showed conflicting results. In addition, 2 studies from the defects or cracks studies claimed the reciprocating motion produced more dentinal defects than the continuous rotating motion. CONCLUSIONS: Instruments with reciprocating motion seemed to have better resistance to cyclic fatigue with less canal transportation tendency than the instruments with continuous rotating motion.restrictio

Computer-aided Design/Computer-aided Manufacturing-guided Endodontic Surgery: Guided Osteotomy and Apex Localization in a Mandibular Molar with a Thick Buccal Bone Plate

A mandibular molar with a thick buccal bone plate is a challenging problem in endodontic surgery despite the increase in the success rate of endodontic surgery nowadays. This report describes the application of a surgical template to guide osteotomy and facilitate apex localization in a mandibular molar with a thick buccal bone plate. A 57-year-old woman visited the authors' clinic for pain in tooth 19 and was diagnosed with symptomatic apical periodontitis in this previously treated tooth. Nonsurgical retreatment was performed; however, 2 years later, the patient reported pain in the same tooth. A periapical lesion was confirmed using cone-beam computed tomographic (CBCT) imaging, and endodontic surgery on the mesial root of tooth 19 was planned. After CBCT imaging and cast scan data were transferred to implant surgical planning software, the data were superimposed. In the superimposed model, an anchor pin was designed to target the mesial root apex of tooth 19. The surgical template was then printed using a 3-dimensional printer. Endodontic microsurgery included application of this printed surgical template. A computer-aided design/computer-aided manufacturing (CAD/CAM)-guided surgical template minimized the extent of osteotomy and enabled precise targeting of the apex in this case. There were no postoperative complications. A CAD/CAM-guided surgical template is useful in endodontic surgery for complicated cases.restrictio

Long-term Prognosis of Pulpal Status of Traumatized Teeth Exhibiting Contradictory Results between Pulp Sensibility Test and Ultrasound Doppler Flowmetry: A Retrospective Study

INTRODUCTION: In this retrospective study, we investigated long-term (over 3 years) follow-up results of teeth that exhibited contradictory results between the pulp sensibility test (thermal or electric pulp test) and ultrasound Doppler flowmetry (UDF) until 1 year after trauma to inspect the prognosis of the pulp. METHODS: Data were collected from the records of trauma patients in our hospital between February 2012 and May 2015. The teeth that had continuously shown contrasting results on the pulp sensibility test and UDF until 1 year after trauma were chosen for the study. Cases with follow-up records of more than 3 years after trauma were finally included, and a retrospective chart review was performed. RESULTS: Data from 343 teeth in 147 patients who visited the hospital with traumatic dental injuries were examined. Among these, 13 teeth from 7 patients were included, and the record of each case was reviewed. All the subjects showed negative responses on the pulp sensibility test and positive responses on UDF until 1 year after trauma. Ultimately, 8 of the 13 teeth recovered pulp sensibility. Two teeth failed to recover pulp sensibility and became symptomatic; root canal treatment was performed on the teeth. The remaining 3 teeth belonged to patients suffering from nerve damage; therefore, the pulp sensibility test was not feasible. CONCLUSIONS: Based on this study, UDF can be effectively used for the evaluation of pulpal status in traumatized teeth.restrictio

Efficacy of Ultrasound Doppler Flowmetry in Assessing Pulp Vitality of Traumatized Teeth: A Propensity Score Matching Analysis

INTRODUCTION: This retrospective study aimed to evaluate and compare the efficacy of ultrasound Doppler flowmetry (UDF) with that of electric pulp testing (EPT) in assessing pulp vitality in traumatized teeth. METHODS: A total of 246 teeth from 78 patients who visited the authors' hospital with histories of dental trauma between February 2012 and May 2015 were included. Patients were divided into 2 groups based on the diagnostic method used to determine pulp vitality during the follow-up visits. In the control group, EPT alone was used to assess pulp vitality, whereas both UDF and EPT were used in the UDF group. Kaplan-Meier survival analysis and the log-rank test were performed after propensity score matching. Survival was defined as the tooth not having to undergo root canal treatment. Additionally, the McNemar test was used to compare the results of UDF with those of EPT in the UDF group. RESULTS: After propensity score matching, 69 teeth were included in each group. The pulp survival rates at 1 year were 74% and 90% in the control and UDF groups, respectively, a difference that was statistically significant (P < .01). In the UDF group, there was a significant difference between the UDF and EPT results at all follow-up evaluations (P < .001). CONCLUSIONS: Within the limitations of this study, UDF appeared to be more sensitive in assessing pulp vitality in traumatized teeth.restrictio

Interrater and intrarater reliability of FDI criteria applied to photographs of posterior tooth-colored restorations

STATEMENT OF PROBLEM: Since 2007, the FDI World Dental Federation (FDI) criteria have been used for the clinical evaluation of dental restorations. However, the reliability of the FDI criteria has not been sufficiently addressed. PURPOSE: The purpose of this study was to assess and compare the interrater and intrarater reliability of the FDI criteria by evaluating posterior tooth-colored restorations photographically. MATERIAL AND METHODS: A total of 160 clinical photographs of posterior tooth-colored restorations were evaluated independently by 5 raters with 9 of the FDI criteria suitable for photographic evaluation. The raters recorded the score of each restoration by using 5 grades, and the score was dichotomized into the clinical evaluation scores. After 1 month, 2 of the raters reevaluated the same set of 160 photographs in random order. To estimate the interrater reliability among the 5 raters, the proportion of agreement was calculated, and the Fleiss multirater kappa statistic was used. For the intrarater reliability, the proportion of agreement was calculated, and the Cohen standard kappa statistic was used for each of the 2 raters. RESULTS: The interrater proportion of agreement was 0.41 to 0.57, and the kappa value was 0.09 to 0.39. Overall, the intrarater reliability was higher than the interrater reliability, and rater 1 demonstrated higher intrarater reliability than rater 2. The proportion of agreement and kappa values increased when the 5 scores were dichotomized. The reliability was relatively lower for the esthetic properties compared with the functional or biological properties. CONCLUSIONS: Within the limitations of this study, the FDI criteria presented slight to fair interrater reliability and fair to excellent intrarater reliability in the photographic evaluation of posterior tooth-colored restorations. The reliability was improved by simplifying the evaluation scores.restrictio