Gingival Squamous Carcinoma with Metastatic Lymph Node Involvement of Papillary Thyroid Carcinoma

Evaluation of Effect of Silvernanoparticle Treated Implant on Bone Formation

The effect of lactic acid concentration and ph of lactic acid buffer solutions on enamel remineralization / 대한치과보존학회지

There are considerable in vitro and in vivo evidences for remineralization and demineralization occurring simultaneously in incipient enamel caries. In order to "heal"the incipient dental caries, many experiments have been carried out to determine the optimal conditions for remineralization. It was shown that remineralization is affected by different pH, lactic acid concentrations, chemical composition of the enamel, fluoride concentrations, etc. Eighty specimens from sound permanent teeth without demineralization or cracks, 0.15 mm in thickness, were immersed in lactic acid buffered demineralization solutions for 3 days. Dental caries with a surface zone and subsurface lesion were artificially produced. Groups of 10 specimens were immersed for 10 or 12 days in lactic acid buffered remineralization solutions consisting of pH 4.3 or pH 6.0, and 100, 50, 25, or 10 mM lactic acid. After demineralization and remineralization, images were taken by polarizing microscopy (x100) and micro-computed tomography. The results were obtained by observing images of the specimens and the density of the caries lesions was determined. 1. As the lactic acid concentration of the remineralization solutions with pH 4.3 was higher, the surface zone of the carious enamel increased and an isotropic zone of the subsurface lesion was found. However, the total decalcification depth increased at the same time. 2. In the remineralization solutions with pH 6.0, only the surface zone increased slightly but there was no significant change in the total decalcification depth and subsurface zone. In the lactic acid buffer solutions with the lower pH and higher lactic acid concentration, there were dynamic changes at the deep area of the dental carious lesion.

Arterial arcade of the maxillary sinus related to sinus bone graft in korean population ; A preliminary study using computed topographies

AIM: The aim of this study was to investigate the arterial arcade of maxillary sinus by determining the distance between the alveolar crest and the inferior border of the vessels in Korean population. MATERIALS AND METHODS: 76 patients and 87 available sinuses were determined by CT scan (Implagraphy, Vatech, Seoul, Korea). The distance between alveolar crest and inferior border of the vessel was determined considering the tooth area of posterior maxilla. RESULTS: The lowest distance was observed on first molar area and the average distance is 16.9 mm. DISCUSSIONS: it is important in sinus lift surgery that the vessels not to be damaged and that the anastomosis is situated in the lateral wall of maxillary sinus, which has to be exposed to gain access to the maxillary sinus. The knowledge of arterial arcade of maxillary sinus is important to perform the sinus floor elevation procedure effectively.

The graft height changes after sinus augmentation procedures using deproteinized bovine bone mineral and beta-tricalcium phosphate: A retrospective comparative study using panoramic radiography

PURPOSE: Previous clinical investigations of sinus floor augmentation have demonstrated repneumatization of grafted sinus. The aim of this study is to evaluate and compare the height changes of sinus floor after grafting with deprotenized bovine bone mineral (DBBM) and beta tricalcium phosphate (TCP). MATERIALS AND METHODS: 34 sinuses in 28 patients were augmented with 100% DBBM or 100% TCP through lateral approaches. Sinusgraft height was measured before, immediately after, and 6 months after bone graft with panoramic radiography. RESULT: After 6 months, the decreases of graft heights were 14.53% for DBBM group and 15.15% for TCP group. There was no statistically significant difference. DISCUSSION AND CONCLUSION: Long-term stability of sinus-graft height represents an important factor for implant success. After the uses of DBBM and TCP for maxillary sinus floor augmentations, acceptable graft height maintenances were observed.

Open versus closed reduction of mandibular condyle fractures: A systematic review of comparative studies

Objective: The objective of this review was to provide reliable comparative results regarding the effectiveness of any interventions either open or closed that can be used in the management of fractured mandibular condyle PATIENTS AND METHODS: Research of studies from MEDLINE and Cochrane since 1990 was done. Controlled vocabulary terms were used. MeSH Terms were "Mandibular condyle" AND "Fractures, bone". Only comparative study were considered in this review using the "limit" function. According to the criteria, two review authors independently assessed the abstracts of studies resulting from the searches. The studies were divided according to some criteria, and following were measured: Ramus height, condyle sagittal displacement, condyle Towns's image displacement, Maximum open length, Protrusion & Lateral excursion, TMJ pain, Malocclusion, and TMJ disorder. RESULTS: Many studies were analyzed to review the post-operative result of the two methods of treatment. Ramus height decreased more in when treated by closed reduction as opposed to open reduction. Sagittal condyle displacement was shown to be greater in closed reduction. Condyle Town's image condyle displacement had greater values in closed reduction. Maximum open length showed lower values in closed reduction. In protrusive and lateral movement, closed reduction was less than ORIF. Closed reduction showed greater occurrence of malocclusion than ORIF. However, post-operative pain and discomfort was greater in ORIF. CONCLUSION: In almost all categories, ORIF showed better results than CRIF. However, the use of the open reduction method should be considered due to the potential surgical morbidity and increased hospitalization time and cost. To these days, Endoscopic surgical techniques for ORIF (EORIF) are now in their infancy with the specific aims of eliminating concern for damage to the facial nerve and of reducing or eliminating facial scars. Before performing any types of treatment, patients must be understood of both of the treatment methods, and the best treatment method should be taken on permission.

Effect of intermittent polymerization on the rate of polymerization shrinkage and cuspal deflection in composite resin / 대한치과보존학회지

This study investigated the effect of intermittent polymerization on the rate of polymerization shrinkage and cuspal deflection in composite resins. The linear polymerization shrinkage of each composite was measured using the custom-made linometer along with the light shutter specially devised to block the light at the previously determined interval. Samples were divided into 4 groups by light curing method; Group 1) continuous light (60s with light on); Group 2) intermittent light (cycles of 3s with 2s light on & 1s with light off for 90s); Group 3) intermittent light (cycles of 2s with 1s light on & 1s with light off for 120s); Group 4) intermittent light (cycles of 3s with 1s light on & 2s with light off for 180s). The amount of linear polymerization shrinkage was measured and its maximum rate (Rmax) and peak time (PT) in the first 15 seconds were calculated. For the measurement of cuspal deflection of teeth, MOD cavities were prepared in 10 extracted maxillary premolars. Reduction in the intercuspal distance was measured by the custom-made cuspal deflection measuring machine. ANOVA analysis was used for the comparison of the light curing groups and t-test was used to determine significant difference between the composite resins. Pyramid showed the greater amount of polymerization shrinkage than Heliomolar (p < 0.05). There was no significant difference in the linear polymerization shrinkage among the groups. The Rmax was group 4 < 3, 2 < 1 in Heliomolar and group 3 < 4 < 2, 1 in Pyramid (p < 0.05). Pyramid demonstrated greater cuspal deflection than Heliomolar. The cuspal deflection in Heliomolar was group 4 < 3 < 2, 1 and group 4, 3 < 2, 1 in Pyramid (p < 0.05). It was concluded that the reduced rate of polymerization shrinkage by intermittent polymerization can help to decrease the cuspal deflection.

Measurement of maxillary sinus volume for the placement of graft material: a case control study using CT image

PURPOSE: The aim of this study is to determine whether a difference in the amount of bone graft material is needed between edentulous patients and dentulous patients and to calculate the amount of augmentation for a sinus lift procedure. METHODS: 19 patients (20 sinuses) were included to measure maxillary sinus volume. Facial CT scanning was performed using MX 8000 IDT CT devices (Philips, USA). And it was used for IDLvm (The IDL Virtual Machine) 6.0, CT Volume Analyzer Ver 2.3 program to measure maxillary sinus volumes RESULTS: At edentulous patients, volumes (mean+/-SD) of the inferior portion of the sinuses were 0.56+/-0.13 cm3 (5mm height), 2.35+/-0.57 cm3 (10mm height), 4.85+/-1.10 cm3 (15mm height). At dentulous patients, volumes (mean+/-SD) of the inferior portion of the sinuses were 0.41+/-0.18 cm3 (5mm height), 1.76+/-0.42 cm3 (10mm height), 3.80+/-0.84 cm3 (15mm height). A significant correlation was found between augmentation height (5mm, 10mm, 15mm) and the calculated sinus volume. (p=0.027, p=0.018, p=0.044) CONCLUSIONS: A significant correlation was found between augmentation height (5mm, 10mm, 15mm) and the calculated sinus volume. Detailed preoperative knowledge of sinus lift augmentation volume is helpful in determining the appropriate amount of the bone graft material.

Micro-shear bond strength to dentin under simulated pulpal pressure / 대한치과보존학회지

The aim of this study was to measure and compare the micro shear bond strengths of the following dentin bonding systems to the dentin surfaces under simulated pulpal pressure; All Bond 2(R), Second(R), AdheSE(R), Adper Prompt L-Pop(R). The occlusal surfaces of 180 extracted human molars were prepared so the dentin bonding surfaces could be exposed. The teeth were randomly assigned to 3 equal groups of 60 each and subdivided. The dentin surfaces were treated with the above mentioned bonding system and resin composite cylinders were built up under a simulated pulpal pressure when saline (Group II) or diluted bovine serum (Group III) was used as the pulpal fluid. As a control, the same procedures were performed in the dried dentin surfaces (Group I). After one day of storage in water, the micro shear bond strengths were measured using an EZ tester. Group II and III showed significantly lower shear bond strength than Group I statistically (p < 0.05). SEbond(R) and AdheSE(R) showed no difference among the different dentin condition. In the Adper Prompt L-Pop(R), a simulated pulpal pressure were applied to the specimens using diluted bovine serum, which showed a higher strength than the specimens in which saline was used (p < 0.05).