• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.45.1-45.8
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• 2020

Objective: The aim of this study was to introduce a gelatin/bovine serum albumin (BSA) tissue standard, which provides dissolution properties identical to those of biological tissues. Further, the study evaluated whether the utilization of endodontic activating devices led to enhanced phantom dissolution rates. Materials and Methods: Bovine pulp tissue was obtained to determine a benchmark of tissue dissolution. The surface area and mass of samples were held constant while the ratio of gelatin and BSA were varied, ranging from 7.5% to 10% gelatin and 5% BSA. Each sample was placed in an individual test tube that was filled with an appropriate sodium hypochlorite solution for 1, 3, and 5 minutes, and then removed from the solution, blotted dry, and weighed again. The remaining tissue was calculated as the percent of initial tissue to determine the tissue dissolution rate. A radiopaque agent (sodium diatrizoate) and a fluorescent dye (methylene blue) were added to the phantom to allow easy quantification of phantom dissolution in a canal block model when activated using ultrasonic (EndoUltra) or sonic (EndoActivator) energy. Results: The 9% gelatin + 5% BSA phantom showed statistically equivalent dissolution to bovine pulp tissue at all time intervals. Furthermore, the EndoUltra yielded significantly more phantom dissolution in the canal block than the EndoActivator or syringe irrigation. Conclusions: Our phantom is comparable to biological tissue in terms of tissue dissolution and could be utilized for in vitro tests due to its injectability and detectability.

• Journal of Technologic Dentistry
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• v.34 no.1
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• pp.11-21
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• 2012

Purpose: Densification and mechanical properties of dental zirconia ceramics were evaluated by different sintering methods. Materials and Methods: Y-TZP zirconia block(Kavo $Everest^{(R)}$ ZS blank, Kavo dental GmbH, Bismarckring, Germany) was used in this study. Sintering were performed in heat sintering furnace and microwave sintering furnace, and then experimented and analyzed on a change in densification according to the sintering time, a change in densification according to thickness, flexural strength and micro-structure in zirconia specimens. Results: Microwave sintering was very effective in considerable mechanical properties such as flexural strength and bulk density was drastically increased than conventional electric heating method. It is also shown that microwave sintering time was faster and more economical than common method to be present in qualities which equal or exceed. Conclusion: It will be important to seek the accurate sintering condition of dental zirconia by microwave sintering method and the continuous research is necessary for the study of relationship between sintering methods and mechanical properties.

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.4
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• pp.229-233
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• 2012

Hemophilia, the most common of the inherited bleeding disorder, is the result of a deficiency of clotting factor. Since bleeding after dental treatment may cause severe or even fatal complications, people with hemophilia must be given special dental care. We report on the diagnosis and treatment of a 9-year-old boy having severe hemophilia visited our department with the chief complaints of pus discharge on the left lower molar region. In the clinical and radiographic examination, periapical abscess and dental caries were diagnosed. Considering complexity of the treatment and complication in the coagulation, it was decided to carry on the treatment under general anesthesia. Clotting factor IX concentrates were intended to provide 50-70% plasma level. Pulpectomy, resin restoration and Stainless steel crown were given under general anesthesia. Several teeth were extracted and the sockets were packed with Surgicel$^{(R)}$ (Oxidized Regenerated Cellulose, Johnson and Johnson Co. Neuchatel, Switzerland) under general anesthesia. Transpalatal arch and lingual arch were given for maintaining the extracted space before discharged. For people with severe hemophilia, factor replacement is necessary before scaling, surgery or regional block injections. Therefore, if several extractions are needed, dental care under general anesthesia would be effective and efficient management.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.4
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• pp.337-344
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• 2021

Background: The primary indication for using long-acting anesthetics in dentistry is extensive dental procedures that require pulpal anesthesia beyond 90 min and management of postoperative pain. Ropivacaine is an amide local anesthetic that is available at various concentrations with inherent vasoconstrictive properties at low concentrations. Ropivacaine has a 75% greater margin of safety than bupivacaine. Ropivacaine can be a good alternative to bupivacaine as a local anesthetic in dental implant surgery as it provides a longer duration of both pulpal and soft tissue anesthesia after mandibular nerve block and lowers CNS and cardiovascular toxicity. This study aimed to evaluate and compare the clinical efficacy of ropivacaine and lignocaine for implant surgery anesthesia. Methods: Fifteen patients with bilateral edentulous sites indicated for implant placement were recruited for this study. Patients aged 20-60 years of both sexes were randomly recruited. Thirty implant placements were performed in the test and control groups using ropivacaine and lignocaine with adrenaline as local anesthetics, respectively. Results: The results were analyzed statistically. The duration of anesthesia was significantly higher in the test group than in the control group. Ropivacaine was found to be superior to lignocaine in terms of the quality of anesthesia. The comparison of mean visual analog scale scores showed ropivacaine to have better anesthetic and analgesic effects than the control group. Conclusion: Ropivacaine 0.75% provides a significantly longer duration of anesthesia than lignocaine 2% with adrenaline. Ropivacaine 0.75% decreased intraoperative and postoperative analgesia compared to lignocaine 2% with adrenaline. Hence, ropivacaine 0.75% can be used as an alternative to lignocaine in implant surgeries and other intraoral surgical procedures that require a longer duration of anesthesia and analgesia.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.335-345
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• 2022

PURPOSE. This in vitro study aimed to evaluate the surface characteristics of a full veneer crown fabricated chairside (CS) from a (Y, Nb)-TZP zirconia block in response to conventional zirconia grinding and polishing. MATERIALS AND METHODS. Zirconia crowns (n = 40) were first prepared and divided into two groups of materials: Labside (LS) and CS, after which each specimen went through a five-step grinding and polishing procedure. Following each surface treatment, surface characteristics were analyzed using confocal laser microscopy (CLSM), average surface roughness (Ra) values were processed from the profile data through Gaussian filtering, and X-ray diffraction pattern analysis was performed to evaluate the monoclinic (M) phase content. Then, a representative specimen was selected for field-emission scanning electron microscopy (FE-SEM), followed by a final analysis of the roughness and X-ray diffraction of the specimens using the independent t-test and repeated measures analysis of variance (RM-ANOVA). RESULTS. In every group, polishing significantly reduced the Ra values (P < .001). There was no significant difference in Ra between the polished state CS and LS. Furthermore, CLSM and FE-SEM investigations revealed that even though grain exposure was visible in CS specimens throughout the as-delivered and ground states, the exposure was reduced after polishing. Moreover, while no phase transformation was visible in the LS, phase transformation was visible in CS after every surface treatment, with the M phase content of the CS group showing a significant reduction after polishing (P < .001). CONCLUSION. Within the limits of this study, clinically acceptable level of surface finishing of (Y, Nb)-TZP can be achieved after conventional zirconia polishing sequence.

• Journal of Oral Medicine and Pain
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• v.47 no.3
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• pp.148-151
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• 2022

Obstructive sialadenitis, one of the diseases that most frequently causes swelling and pain in the salivary glands, is mainly caused by structural obstructions. Sialolithiasis is the most frequent cause of the disease, and other causes include calculus formation, duct strictures, foreign bodies, and anatomical variations. Although there is a possibility that facial fillers directly block the salivary ducts, no cases of obstructive sialadenitis associated with them have been reported yet. We report the case of a 34-year-old female patient who complained of recurrent swelling and pain in the left buccal mucosa. She had undergone facial filler injection procedures on her facial area for cosmetic purposes several years before. Based on the findings of magnetic resonance imaging (MRI) and MR sialography, she was diagnosed with obstructive sialadenitis due to facial fillers. Through this case, we should remember to obtain a thorough history including filler treatments in the case of parotid gland swelling. We also suggest proper utilization of advanced imaging such as MRI in evaluating the location of facial fillers.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.9-18
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• 2017

Objectives: This study evaluated color differences (${\Delta}Es$) and translucency parameter changes (${\Delta}TPs$) of various computer-aided design/computer-aided manufacturing (CAD/CAM) blocks after immersion in coffee. Materials and Methods: Eight CAD/CAM blocks and four restorative composite resins were evaluated. The CIE $L^{\ast}a^{\ast}b^{\ast}$ values of 2.0 mm thick disk-shaped specimens were measured using the spectrophotometer on white and black backgrounds (n = 6). The ${\Delta}Es$ and ${\Delta}TPs$ of one day, one week, and one month immersion in coffee or water were calculated. The values of each material were analyzed by two-way ANOVA and Tukey's multiple comparisons (${\alpha}=0.05$). The ${\Delta}Es$ after prophylaxis paste polishing of 1 month coffee immersion specimens, water sorption and solubility were also evaluated. Results: After one month in coffee, ${\Delta}Es$ of CAD/CAM composite resin blocks and restorative composites ranged from 1.6 to 3.7 and from 2.1 to 7.9, respectively, and ${\Delta}TPs$ decreased. The ANOVA of ${\Delta}Es$ and ${\Delta}TPs$ revealed significant differences in two main factors, immersion periods and media, and their interaction except for ${\Delta}Es$ of TEL (Telio CAD, Ivoclar Vivadent). The ${\Delta}Es$ significantly decreased after prophylaxis polishing except GRA (Gradia Block, GC). There was no significant correlation between ${\Delta}Es$ and water sorption or solubility in water. Conclusions: The ${\Delta}Es$ of CAD/CAM blocks after immersion in coffee varied among products and were comparable to those of restorative composite resins. The discoloration of CAD/CAM composite resin blocks could be effectively removed with prophylaxis paste polishing, while that of some restorative composites could not be removed.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.40.1-40.10
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• 2019

Objectives: This study aimed to assess the effect of DentalVibe on the level of pain experienced during anesthetic injections using 2 different techniques. Materials and Methods: This randomized crossover clinical trial evaluated 60 patients who required 2-session endodontic treatment. Labial infiltration (LI) anesthesia was administered in the anterior maxilla of 30 patients, while inferior alveolar nerve block (IANB) was performed in the remaining 30 patients. 1.8 mL of 2% lidocaine was injected at a rate of 1 mL/min using a 27-gauge needle. DentalVibe was randomly assigned to either the first or second injection session. A visual analog scale was used to determine participants' pain level during needle insertion and the anesthetic injection. The paired t-test was applied to assess the efficacy of DentalVibe for pain reduction. Results: In LI anesthesia, the pain level was 12.0 ± 15.5 and 38.1 ± 21.0 during needle insertion and 19.1 ± 16.1 and 48.9 ± 24.6 during the anesthetic injection using DentalVibe and the conventional method, respectively. In IANB, the pain level was 14.1 ± 15.9 and 35.1 ± 20.8 during needle insertion and 17.3 ± 14.2 and 39.5 ± 20.8 during the anesthetic injection using DentalVibe and the conventional method, respectively. DentalVibe significantly decreased the level of pain experienced during needle insertion and the anesthetic injection in anterior LI and mandibular IANB anesthesia. Conclusions: The results suggest that DentalVibe can be used to reduce the level of pain experienced by adult patients during needle insertion and anesthetic injection.

• The Journal of the Korean dental association
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• v.48 no.1
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• pp.6-11
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• 2010

Amid the rapid transitions in both local and international markets, the Korean dental industry is facing more challenges than at any time in its history. This paper tried to address some of the key issues faced by the industry as well as the policy issues and I direction of implementation that the Korean Dental Association (KDA) is expected to tackle. First, the direction of reforming the country's health insurance system was examined with emphasis on the expected changes in and improvement of the fee-for-service reimbursement system (FFSRS) and medical reimbursement system (MRS). With FFSRS, the most urgent issue would be ameliorating the current lop-sided, unreasonable reimbursement system that prevents suppliers from voicing their opinions. To help achieve that goal, the limited authority and responsibility of the president of National Health Insurance Corporation (NHIC) as one of the contract-making parties must be clarified. In addition, the functions of NHIC's Health Insurance Finance Committee must be restricted; at the same time, the panel organization of the Health Insurance Policy Review Committee needs to be reformed to embrace greater democracy. As with MRS, the government is considering a block budget bill to help promote efficiency in employing and managing the health insurance fund. Policymakers must understand that the implementation of such proposal could exacerbate an already dire situation. Improving MRS requires meeting the following preconditions: (a) the structurally vicious cycle of small charge-small salary needs to be resolved, and a certain percentage of fee raise must be guaranteed on a yearly basis to help adjust the fee system to a more realistic level; (b) the supply-and-demand balance in producing health care professionals must be improved including the prevention of oversupply of doctors, nurses, etc., and; (c) institutional strategies must be provided to enhance the quality of medical care and ensure academic advancement in health care disciplines.

• Journal of the Korean institute of surface engineering
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• v.42 no.1
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• pp.41-46
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• 2009

The fit between dental implant fixture and zirconia abutment is affected by many variables during the fabrication process by CAD/CAM program and milling working. The purpose of this study was to evaluate the surface compatibility and electrochemical behaviors of zirconia abutment for prosthodontics. Zirconia abutments were prepared and fabricated using zirconia block and milling machine. For stabilization of zirconia abutments, sintering was carried out at $1500^{\circ}F$ for 7 hrs. The specimens were cut and polished for gap observation. The gap between dental implant fixture and zirconia abutment was observed using field-emission scanning electron microscopy (FE-SEM). The hardness and corrosion resistance of zirconia abutments were observed with vickers hardness tester and potentiostat. The gap between dental implant fixture and zirconia abutment was $5{\sim}12{\mu}m$ for small gap, and $40{\sim}60{\mu}m$ for large gap. The hardness of zirconia surface was 1275.5 Hv and showed micro-machined scratch on the surface. The corrosion potentials of zirconia abutment/fixture was .290 mV and metal abutment/fixture was .280 mV, whereas $|E_{pit}-E_{corr}|$ of zirconia abutment/fixture (172 mV) was higher than that of metal abutment/fixture (150 mV). The corrosion morphology of metal abutment/fixture showed the many pit on the surface in compared with zirconia abutment/fixture.