The purpose of this study was to assess the correlation between integrated mineral loss (volume % mineral×µm, ΔZ(TMR)) determined using transverse microradiography (TMR) and integrated reflectivity (dB×µm, ΔR(OCT)) determined using optical coherence tomography (OCT) for detecting early dental caries with lesion depth more than 200 µm. Sixty tooth specimens were made from sound bovine teeth. They were immersed in a demineralized solution for 20, 30, and 40 days. The ΔR(OCT) was obtained from the cross-sectional OCT image. The ΔZ(TMR) was obtained from the TMR image. The correlation between ΔR(OCT) and ΔZ(TMR) was examined using Pearson correlation. The Bland-Altman plot was constructed using the ΔR(OCT) and ΔZ(TMR) values. A significant correlation between ΔR(OCT) and ΔZ(TMR) was confirmed (r=0.491, p=0.003). Moreover, most of the difference between ΔR(OCT) and ΔZ(TMR) was included in the error section of the Bland-Altman plot. Therefore, OCT could be used as a substitute for TMR when analyzing mineral loss in early dental caries.
Dental Caries* ; Microradiography ; Miners ; Tomography, Optical Coherence* ; Tooth

Dental caries is a chronic disease that causes the destruction of tooth structure by the interaction of plaque bacteria, food debris, and saliva. There has been attempts to induce remineralization by supersaturating the intra-oral environment around the surface enamel, where there is incipient caries. In this study, supersaturated remineralized solution "R" was applied to specimens with incipient enamel caries, and the quantitative ananlysis of remineralization was evaluated using microradiography. Thirty subjects volunteered to participate in this study. Removable appliances were constructed for the subjects, and the enamel specimen with incipient caries were embedded in the appliances. The subjects wore the intra-oral appliance for 15 days except while eating and sleeping. The removable appliance were soaked in supersaturated solution "R", saline, or Senstime(R) to expose the specimen to those solutions three times a day, 5 minutes each time. After 15 days, microradiography was retaken to compare and evaluate remineralization. The results were as the following: 1. The ratio of remineralized area to demineralized area was significantly higher in the supersaturated solution "R" and Senstime(R) than in the saline. (p<0.05) 2. Remineralization in the supersaturated buffer solution "R" occurred in the significantly deeper parts of the tooth, compared to the Senstime(R) group containing high concentration of fluoride.(p<0.05) As in the above results, the remineralization effect of remineralized buffer solution "R" on incipient enamel caries has been proven. For clinical utilization, further studies on soft tissue reaction and the effect on dentin and cementum are necessary. In conclusion compared to commercially available fluoride solution, remineralization solution "R" showed better remineralization effect on early enamel caries lesion, so it is considered as effecient solution for clinical application.
Bacteria ; Chronic Disease ; Dental Caries ; Dental Cementum ; Dental Enamel ; Dentin ; Eating ; Fluorides ; Microradiography ; Tooth

The purpose of this study was to investigate the effects of the Co-60 gamma irradiation on the osseointegration. 2.0 mm titanium alloy screw implants were placed in the tibial metaphysis of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15 Gy from 60Co teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non-irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy. The obtained results were as follows; 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.
Alloys ; Bone Marrow ; Bone Remodeling ; Connective Tissue ; Cytoplasm ; Haversian System ; Injections, Intramuscular ; Microradiography ; Microscopy ; Osseointegration* ; Osteogenesis ; Rabbits ; Tetracycline ; Tibia ; Titanium

BACKGROUND AND OBJECTIVES: Conventional studies for the middle ear ossicles destructed by cholesteatoma give relatively limited information on shape, mechanical strength and 3-dimensional relationship. Recently, Micro-CT scanning technology has been applied to analysis of skeletal structure. This study aims to reconstruct the 3-dimensional structure of normal ossicles and destructed ossicles by different cholesteatomas and to compare volume fraction of destructed ossicles with that of normal ossicles. MATERIALS AND METHOD: 13 pathological ossicles obtained during cholesteatoma surgery were used in this study (2 malleuses and 2 incuses from attic cholesteatoma;1 malleus and 2 incuses from sinus cholesteatoma;2 malleuses and 2 incuses from tensa retraction cholesteatoma; 2 incuses from congenital cholesteatoma). As a control, normal ossicles harvested from cadaveric temporal bone specimens were used. The structure of obtained ossicles was analyzed through Micro-CT (SkySan-1072, Belgium) by filming the 2-dimensional cross section image running perpendicular to the long axis of the ossicles. The 3-dimensional images were thereby reconstructed for each, and were analyzed using CT-Analyzer(TM) and ANTTM. Based on the results, the strength of each ossicle were measured. RESULTS: The volume fraction, indicating relative strengths of ossicles, was lower in the portion of destructed surface. The pattern of destructed ossicles by cholesteatoma was different according to pathological status of cholesteatoma. CONCLUSION: Our preliminary data of ossicular structure analyzed by Micro-CT scan will be helpful for elucidation of pathological ossicles in middle ear cholesteatoma and will make a great contribution to research of middle ear cholesteatoma.
Axis, Cervical Vertebra ; Cadaver ; Cholesteatoma* ; Cholesteatoma, Middle Ear ; Ear Ossicles ; Ear, Middle ; Humans* ; Imaging, Three-Dimensional ; Incus ; Malleus ; Microradiography ; Running ; Temporal Bone