• 대한치과보철학회지
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• 제51권2호
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• pp.119-124
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• 2013

과도한 마모를 보이는 환자는 광범위한 수복 치료를 필요로 하는 경우가 많다. 마모의 원인은 주로 교모에 의해 발생하나 이외에도 여러 가지 유발 요인이 있으며 치료 계획은 이러한 마모의 양상과 병인 분석에서 가장 먼저 시작되어야 한다. 발달된 저작근과 치조돌기, 높은 교합력을 보이며 수축 상태와 안정 상태의 근육길이 차이가 적어 악간 간격이 많지 않은 환자는 수직 고경 상실에 대한 평가와 수복물의 설계가 더욱 신중하게 이루어져야 한다. 치아 길이의 감소는 그에 상응하는 치조골 높이 신장에 의해 보상될 수 있으며 수직고경의 항상성이 유지되는 것이므로, 이 경우 수직고경의 섣부른 증가는 근피로감, 치아의 압하 및 통증, 보철물의 파절등을 초래할 수 있다. 본증례의 환자는 다수 치아의 마모와 이 악물기 습관이 관찰된 환자로, 수직고경의 증가를 동반하여 상악 무치악 부위는 아말감을 삽입한 가철성 국소의치, 상하악 유치악 부위는 고정성 보철물로 수복을 하였으며, 이에 기능적인 면과 심미적인 면에서 만족스러운 결과를 얻었기에 치험례를 보고하고자 한다.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1720-1729
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• 2001

Wear characteristics of Nylon and acetal pinions against steel gears for different pitch line velocities was studied with a power circulating gear test rig under unlubricated condition. Specific wear rate was measured as a function of tooth number, module, tooth width and total revolution. The worn tooth surfaces were examined with a profile projector. The Nylon pinion showed lower specific wear rate than the acetal pinion. However, the Nylon pinion was fractured at high tooth loads, whereas the acetal pinion exhibited a steady wear behavior. The wear characteristics of Nylon pinion varied significantly with the Pitch line velocity. Wear occurred most severely at the tooth tip and the region immediately below the pitch line of pinion. The dominant wear mechanisms were adhesion and abrasion.

• 대한치과기공학회지
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• 제39권1호
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 2001년도 추계학술대회
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• pp.53-53
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• 2001

• 대한소아치과학회지
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• 제35권3호
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• pp.509-515
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• 2008

현대 사회에서 증가하고 있는 산성 음료의 소비는 치아 부식의 원인으로 주목받고 있다. 이에 본 연구에서는 산성 음료와 산부식 용액, 산성 음료 적용 후 칫솔질, 산성 음료 적용 후 우유, 타액, Tooth $Mousse^{(R)}$ 의 적용이 치아 법랑질 표면 재광화에 미치는 영향을 평가하기 위해 사람 소구치의 치관 시편을 제작하여 각각을 적용시킨 후 scanning electron micrograph (SEM)를 촬영한 결과 다음과 같은 결과를 얻었다. 1. Coca-Cola와 Chilsung-Cider의 산도는 FineEtch 37과 self-etching primer인 $Tyrian^{TM}SPE$의 산도보다 높았다. 2. Coca-Cola, Chilsung-Cider, FineEtch 37, $Tyrian^{TM}SPE$를 적용한 후 촬영한 SEM 사진에서 법랑질 표면의 부식된 양상을 비교한 결과 Coca-Cola와 Chilsung-Cider의 산부식 정도가 나머지 둘의 산부식 정도보다 낮은 양상을 보였다. 3. Coca-Cola, Chilsung-Cider를 적용한 후 우유, 타액, Tooth $Mousse^{(R)}$를 적용시키고 촬영한 SEM 결과 모두 비슷한 양상을 보였으며 이는 부식된 법랑질 표면보다 덜 부식된 양상을 보였다. 4. Coca-Cola를 적용시킨 다음 칫솔질한 후와 Coca-Cola, 타액, 칫솔질의 순서로 적용한 후 촬영한 SEM 결과, 타액을 적용시킨 법랑질의 표면이 덜 부식된 양상을 보였다.

• 대한소아치과학회지
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• 제24권1호
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• pp.112-124
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• 1997

According to extensive use of composite resin which have superior esthetic property, every effort on improving bonding strength between a tooth and composite resin has been continued. Acid etching technique is a method that micro-etches the tooth surface which provides bonding with composite resin possible. Recently, there were several reports that mechanical treatment obtained from air-abrasion can provide similar bonding strength with acid etching technique. So, this experimental study was designed to compare the shear bonding strength between using air-abrasion technique and using acid etching technique. Initially, bovine teeth were divided into enamel and dentin experimental groups. Respectively each group was categorized into three subgroups. One subgroup was acid etched with 35% phosphoric acid, then bonded with composite resin. The other subgroup was air-abraded with $50{\mu}m$ $Al_2O_3$ particles sprayed with 160psi air pressure using air abrasion unit(KCP-1000, A.D.T., U.SA), and composite resin was bonded. In another subgroup, composite resin was bonded after acid etching following air-abrasion. So, enamel experimental groups were made of E1 (acid etched only), E2(air-abraded only), E3(acid etched following air-abraded), and dentin experimental groups were made of D1(acid etched only), D2(air-abraded only), D3(acid etched following air-abraded). Each subgroup had 10 specimens. Dentin bonding system(Scotchbond Multi-purpose, 3M Co., U.S.A.) and composite resin(Z-100, 3M Co., U.S.A.) were applied on treated surface using 5mm diameter gelatin capsule as manufacturer's direction. After 1200 times thermocycling between $5^{\circ}C$ and $55^{\circ}C$, shear bond strength was measured in 5mm/min crosshead speed with Instron(Instron Co., U.S.A.), and also treated enamel and dentin were observed with SEM(JEOL Co., Japan). The following results were obtained: 1. In the enamel experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 2. In the dentin experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 3. In the SEM study, air-abraded enamel and dentin had irregular and rough surfaces.

• 구강회복응용과학지
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• 제34권3호
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• pp.137-146
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• 2018

치아 마모로 인해 치아 경조직은 없어지게 된다. 이것은 여러 가지 변수가 작용하는 과정이다. 오랜 시간 동안 치아 마모는 일상적인 임상 영역에서는 별다른 과심을 받지 못하였지만 최근 들어 관심이 점점 더 커지고 있다. 인간의 평균 수명이 계속 늘어가면서 치아의 중요도가 더 증가하기도 하였고 구강 위생이 보편화되고 치과 치료가 발전하면서 치아가 더욱 오랜 동안 구강 내에서 유지되고 있기 때문에 치아 마모가 더 많은 관심을 불러 일으키고 있는 것이다. 치아 마모는 자연적으로 한방향성을 가지고 있기 때문에 이를 통해 개개인의 연령 감정을 하는데 자주 이용되었다. 당연하게도 치아 마모를 이용한 연령감정은 상대적으로 넓은 범주에서 이루어지고 그 정확성도 의심받고 있다. 고대에서 중세시대까지 치아 마모는 아주 심하게 있어왔다. 그래서 치아 마모는 매우 많은 지역에서 연구되어 왔다. 하지만 아직 이런 개개의 연구들이 통합적인 의미 도출로 이어지지는 못하고 있다. 따라서 지금까지의 연구들을 토대로 통합적인 치아 마모의 이해를 위한 세부적인 연구와 접근이 필요한 시점이다.

• The Journal of Advanced Prosthodontics
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• 제13권1호
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• pp.1-11
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• 2021

PURPOSE. The study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment. MATERIALS AND METHODS. Four hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test. RESULTS. The maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)]. CONCLUSION. The comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.

• 대한치과보철학회지
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• 제38권3호
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• pp.336-347
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• 2000

Statement of problem. Luster loss in esthetic anterior ceromer restoration can occur and can be related with rough surface texture. Understanding durability of surface finishing methods like polishing and surface coating have critical importance. Purpose. This study evaluated the effect of tooth brushing and thermal cycling on surface luster of 3 ceromer systems (Artglass, Targis, Sculpture) treated with different surface finishing methods. Material and methods. Seventy-two samples were prepared: 12 for control group Z100, 12 for Artglass, 24 for Targis, and 24 for Sculpture. Half of the Targis and Sculpture were polished according to the manufacturer's recommendation. The rest of the samples were coated with staining and glazing solution for Targis and Sculpture, respectively. All specimens were subjected to 10,000 cycles between $5^{\circ}C\;and\;55^{\circ}C$ with 30 seconds dwell time. Tooth brushing abrasion tests were performed in a customized tooth brushing machine with 500g back and forth for 20,000 cycle. Luster comparisons were based on grading after direct observation, and light reflection area was measured with Image analysis software. Results. All materials showed an decrease in luster grade after thermal cycling and tooth brushing. The post-tooth brushing results revealed that the glazed Sculpture had greater mean luster grade than did any other groups. While, the stained Targis group showed greatest changes after tooth brushing (p < 0.05), polished Targis and Sculpture did not show significant changes. However, glazed Sculpture showed discretely fallen out glaze resin. Conclusion. From the results of this study, all of the ceromer specimens were much glossy than control composite group after tooth brushing. coatings used for Targis and Sculpture had not durability for long term use.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.819-828
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• 1997

The purpose of this study was to evaluate the abrasion-resistance of root surface after NaF iontophoresis, Nd:YAG laser irradiation and combined treatment 50 anterior teeth with flat interproximal root surface that had been extracted due to periodontal destruction were selected. All teeth were treated by the same procedure as conventional periodontal root treatment, such as scaling and root planing, root conditioning with tetracycline HCI(lOOmg/ml, 5min). The pre-treatment weight of each tooth was measured by a dial scale(SHIMADEU Co, LIBROR EB-220HU, capacity 220.000 g, Japan). All teeth were divided into 5 groups as follows: Nd:YAG laser irradiation(group 1, 1 W, 100 mJ, 10Hz, fiberoptic-root surface distance=5mm, $10\;sec.{\times}6times$, EL.EN.EN060, Italy): NaF iontophoresis(group 2, $150{\mu}A$, 4 min}: Nd:YAG laser irradiation following NaF iontophoresis(group 3): NaF iontophoresis following Nd:YAG laser irradiation(group 4): No treatment(control group). Electric toothbrushing (Oral-B, Brown Co, Germany) was conducted during 1 hour($lO\;min.{\times}6\;times$). Subsequently post-treatment weight was remeasured by the same method as pre-treatment weight measurement. The difference of abrasion rate among all groups was statistically analyzed by ANOVA(SAS program). Following results were obtained: 1. The abrasion rate was significantly lower in Nd:YAG laser irradiation group than NaF iontophoresis group(p < 0.001). 2. The abrasion rate was significantly lower in combined groups of Nd:YAG laser irradiation and NaF iontophoresis than either Nd:YAG laser irradiation group or NaF iontophoresis group(p < 0.001). 3. There was no significant difference in abrasion rate according to application order in the combined groups(p > 0.05). 4. The abrasion rate was significantly lower in all experimental groups than control group(p < 0.001). The results suggest that combined treatment of Nd:YAG laser irradiation and NaF iontophoresis on exposed root surface after periodontal therapy can enhance the abrasion-resistance of root surface and may inhibit the root caries development.