Effect of remineralization and inhibition to demineralization after fluoride gel or hydroxyapatite paste application on stripped enamel / 대한치과교정학회지

OBJECTIVE: The aim of this study was to evaluate the effect of remineralization and inhibition to demineralization after fluoride gel (acidulated phosphate fluoride, APF) or hydroxyapatite (HAp) paste application on interdentally stripped teeth. METHODS: After interdental stripping, 1.23% APF or 5%, 10% HAp paste were applied for 7 days for remineralization. Afterwards, teeth were exposed to lactate carbopol buffer solution for demineralization. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to compare change in surface contents and crystal structures after remineralization, and then after demineralization. RESULTS: EDS analysis indicated that calcium (p < 0.001) and phosphate (p < 0.01) contents were increased after 10% HAp paste application on stripped enamel, calcium (p < 0.05) and phosphate (p < 0.01) contents were increased after 5% HAp paste application, and fluoride (p < 0.01) contents were increased after 1.23% APF application. SEM image showed that enamel surfaces became smoother and crystal structures became small and compact after APF or HAp application. After demineralization, calcium (p < 0.05) and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 10% HAp paste, and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 5% HAp paste. After demineralization, surfaces looked less destroyed in the enamel remineralized beforehand than those of the control, and small pores between crystal structures, formed by remineralization were remained. CONCLUSIONS: Hydroxyapatite paste and fluoride gel were helpful to remineralize and inhibit deminerlization on stripped enamel.

Shear bond strength of rebonded ceramic brackets / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the shear bond strength of rebonded ceramic brackets according to each condition and find an appropriate method to rebond ceramic brackets with proper shear bond strength in clinical practice. METHODS: The study consisted of 12 experimental groups, according to the types of brackets, debonding methods, and treatment methods of the bracket base. Shear bond strength was measured, and adhesive residues left on the tooth surface were assessed. The base of the bracket was examined under scanning electron microscopy. RESULTS: The shear bond strength of the monocrystalline ceramic bracket group was significantly higher than thatof the polycrystalline bracket group with only sandblasting (p 0.05). The shear bond strength of the sandblasted/silane group was significantly higher than that of the selectively grinded group with a low-speed round bur and the sandblasted only group (p < 0.001). The retentive structure was more presented in groups where laser was applied than in groups where shear force was applied to debond brackets prior to rebonding. The bracket bases which were treated before rebonding presented smoother surfaces than new brackets. CONCLUSIONS: Shear bond strength could be increased by applying a silane coupling agent after sandblasting before rebonding. Also, the bond strength of the selectively grinded group with a low-speed round bur and the sandblasted group showed acceptable bond strength for clinical orthodontic treatment.

Psychological Analysis with Symptom Check List-90-Revision in Patients with Tinnitus / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Psychological distress may develop from tinnitus, or that recognition of tinnitus may even be greater during exposure to environmental stress. So, patients with tinnitus need to consider the psychologic aspect in their diagnosis and treatment. The aim of this study is to evaluate the degree and characteristics of the psychologic factors associated in patients undergoing tinnitus retraining therapy. MATERIALS AND METHOD: 119 patients with tinnitus who received the Symptom Check List-90-Revision (SCL-90-R) and a control group without tinnitus were compared first; and then 92 out of 119 patients performed the follow up study after three months of tinnitus retraining therapy. RESULTS: The results were as follows. 1. The tinnitus group scored higher than the control group in somatization, anxiety, phobic anxiety (p0.05). 3. The psychologic aspect of patients with tinnitus were related to loudness, pitch, annoyance (p<0.05). 4. The follow-up study of 3 months on patients who underwent tinnitus retraining therapy showed diminished score in all components of SCL-90-R, except phobic anxiety, and paranoid (p<0.05). CONCLUSION: This study indicated that the compliant behaviour of tinnitus is related closely with intrinsic psychodynamic mechanism.

Tinnitus Masking Effects Using Various Kinds of Sound and Music / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Even though various methods have been tried to diagnose and treat tinnitus, researchers have fallen short of providing the accurate characteristics since most tinnitus are presented as a subjective symptom. A few researchers have tried to assimilate tinnitus using computer and music synthesizers, however, their efforts have not yet been developed as generalized treatment modalities. In this study, we attempted to induce not only tinnitus masking but also psychological stability with various kinds of sound and music and to analyse its treatment effects. The aim of this study is to make a step toward developing tinnitus treatment. MAERIALS AND METHODS: The subjects were 28 patients with constant tinnitus, who visited the otolaryngology department of Seoul Paik Hospital, Medical College of Inje University from June to December of 1997. We tried to objectify the tinnitus as close to the actual sound as possible by synthesizing the modulation of the broad band noises and recording not only the existing pure tones and broad band noises but also the natural and artificial sounds which the patients could easily hear from their surroundings. And then we tried to mask tinitus with various natural, artificial and synthetic sounds, including its frequency band. We also let them hear the tapes for contemplation and various music. RESULTS: The results were as follows. 1) As for the quality of tinnitus, 13 patients reported similarity to the pure tone (46.4%), seven to narrow band noise (25%), eight to natural environmental sounds (21.4%), one each to artificial environmental sound and white noise (3.6%) and no one to synthetic sound. 2) The sound that masked tinnitus well was three octave broad band noise including the tinnitus frequency. 3) Twenty four patients (85.7%) chose music as the most comfortable sound to listen to. 4) Three patients (10.7%) replied that their tinnitus were decreased in amplitude and 15 patients (53.6%) reported that it was easier to stand the tinnitus even though their tinnitus persisted. CONCLUSION: Based on these results, it can be concluded that music therapy provides psycological stability in addtion to inducing masking effect, even though it can't directly decrease nor completely remove tinnitus. Thus we believe that a more effective result can be obtained if music therapy is implemented on a gradual basis as a part of the whole treatment process.

Effects of Salicylate on ABR and ECoG in Guinea Pig / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It has been recognized that salicylate induces ototoxicity in animals and humans. Many studies have been done to identify the mechanisms of ototoxicity of salicylate with histopathological, biochemical and electrophysiological methods. Among these methods, the electrophysiological method is useful for clinical diagnosis and evaluation of therapeutic effect. The studies reported here were aimed at performing electrophysiological effects of salicylate by using Auditory Brainstem Response (ABR) and Electrocochleography (EcoG) through non-invasive approach. MATERIAL AND METHODS: Auditory brainstem response and electrocochleogram were observed by non-invasive approaching method after the intraperitoneal injection of 450 mg/kg of lysine salicylate on 10 ears of 5 guinea pigs. RESULTS: The threshold shifting of ABR and ECoG were less than 10 dB. The latency of ABR waves and Summating Potential were increased after salicylate was administered especially at low intensity sound stimulation. CONCLUSION: The latency of ABR wave and SP would be useful in diagnosing ototoxicity and evaluating the therapeutic effect in ototoxic patients.

Comparative Analysis on Anatomical Measurements of Paranasal Sinuses Using Nasal Endoscope and CT / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It is rare to find any studies reporting on the practical measurements of landmarks in the paranasal sinuses that are done intraoperatively as well as comparative analysis on the anatomical and radiological measurements of the paranasal sinuses. The aim of this study was to analyze the anatomical measurements of the paranasal sinuses using nasal endoscope and CT scout films to determine the statistical significance. MATERIALS AND METHODS: In 130 patients the authors used bayonet forceps and seekers to measure the distances from the anterior nares to some of the intranasal structures, such as the uncinate process, bulla ethmoidalis, basal lamella, maxillary ostium, posterior wall of ethmoid sinus, anterior wall of sphenoid sinus and posterior wall of sphenoid sinus. Then, using the CT scout films, we measured the distances between the anterior nasal spine and the basal lamella (B.L.), the anterior wall of sphenoid sinus (A.W.S.), and the posterior wall of sphenoid sinus (P.W.S.). We analyzed the mean values of the basal lamella, the anterior and posterior wall of sphenoid sinus from all the available data in order to compare the endoscopic and radiologic measurements, and carried out a paired t-test. RESULTS: There was a statistically significant discrepancy in the comparative analysis of the CT scout film and the endoscopic measurements of the basal lamella, anterior wall of sphenoid sinus and posterior wall of sphenoid sinus, althought there were no significant discrepancy for basal lamella in female patients (p>0.05). CONCLUSION: The differnces between the CT and operative measurements observed in this study were due to differnt measuring points, differences in the measuring angles, and inaccurate locations of the landmarks on the CT scout films owing to their small sizes. These findings indicate that a more accurate method need to be introduced in using the CT films to measure the anatomical landmarks in the paranasl sinuses.