• 구강회복응용과학지
• /
• 제40권1호
• /
• pp.24-30
• /
• 2024

청소년기 외상으로 인한 상악 전치부의 복잡 치관 파절은 기능적, 심미적 문제를 야기할 수 있다. 치수 노출을 동반한 치관 파절은 남아있는 치질의 양에 따라 다양한 수복 방법을 고려할 수 있다. 직접 레진 수복은 가장 일차적으로 고려되는 전통적이고 효과적인 방법이나 시간이 지남에 따라 변색되고 깨질 가능성이 높다. 전장관 수복은 성장기의 치아 이동으로 변연 부조화에 의한 재수복 가능성이 높으며 광범위한 치관 파절 시 주로 시행하는 포스트 수복은 치근 천공 및 치근 파절의 위험성을 증가시킨다. 그러나 Endocrown은 치수강 공간으로부터 유지력을 얻을 수 있는 일체형 구조로 생체역학적 측면에서 효과적인 재건이 가능하고 기능과 심미성의 회복에 유리한 이점을 제공한다. 따라서 Endocrown은 청소년기 외상으로 인한 복잡 치관 파절의 수복 방법으로 고려할 수 있다.

• 대한소아치과학회지
• /
• 제36권2호
• /
• pp.288-292
• /
• 2009

치관-치근 파절(crown-root fracture)은 법랑질, 상아질, 백악질에 파급된 파절이며 치수노출을 수반하는 것과 수반하지 않는 것이 있다. 치근부위만 파절된 경우와 달리 치관-치근 파절의 경우 치수와 치주조직을 통해 세균감염이 발생하기 때문에 치유를 기대하기 힘들다. 파절은 치근을 따라 다양한 부위에서 일어나기 때문에 치료방법은 파절 정도에 따라 결정된다. 치근의 파절선이 치관부에 근접 한 경우 느슨한 치아 파절편을 제거 한 후, long junctional epithelium이 형성되도록 치은을 노출된 상아질에 맞게 적합시키거나, 외과적으로 파절 부위를 노출시키거나, 교정적 또는 외과적으로 치아를 정출시키는 방법 등을 고려해 볼 수 있지만 파절선이 깊은 경우 발치가 일반적이다. 그러나 최근 논문에서 수직 치관-치근 파절된 치아에 대해 발치대신 레진으로 파절선을 수복한 후 재식하여 성공한 사례가 발표되었다. 이 방법으로 치아를 보존할 수 있으며 이러한 방법이 전치 부에서는 예후가 좋다고 보고되었다. 본 증례에서는 외상으로 인하여 상악중절치의 치관-치근 파절이 발생한 10세 환아에서 해당 치아를 발치하여 레진으로 파절부위를 재부착한 후 재식하였다. 그러나 18개월간 주기적으로 관찰한 결과 문헌에서와 같은 좋은 결과를 나타내지는 않았다.

• The Journal of Advanced Prosthodontics
• /
• 제9권5호
• /
• pp.328-334
• /
• 2017

PURPOSE. This study evaluated fracture resistance with regard to ferrule lengths and post reinforcement on endodontically treated mandibular premolars incorporating a prefabricated post and resin core. MATERIALS AND METHODS. One hundred extracted mandibular premolars were randomly divided into 5 groups (n=20): intact teeth (NR); endodontically treated teeth (ETT) without post (NP); ETT restored with a prefabricated post with ferrule lengths of either 0 mm (F0), 1 mm (F1), or 2 mm (F2). Prepared teeth were restored with metal crowns. A thermal cycling test was performed for 1,000 cycles. Loading was applied at an angle of 135 degrees to the axis of the tooth using a universal testing machine with a crosshead speed of 2.54 mm/min. Fracture loads were analyzed by one-way ANOVA and Tukey HSD test using a statistical program (${\alpha}=.05$). RESULTS. There were statistical differences in fracture loads among groups (P<.001). The fracture load of F2 ($237.7{\pm}83.4$) was significantly higher than those of NP ($155.6{\pm}74.3N$), F0 ($98.8{\pm}43.3N$), and F1 ($152.8{\pm}78.5N$) (P=.011, P<.001, and P=.008, respectively). CONCLUSION. Fracture resistance of ETT depends on the length of the ferrule, as shown by the significantly increased fracture resistance in the 2 mm ferrule group (F2) compared to the groups with shorter ferrule lengths (F0, F1) and without post (NP).

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제28권1호
• /
• pp.49-57
• /
• 2006

Mandibular fractures have higher incidence rate compared to facial bone fractures because of relatively prominent form. Specially, mandibular angle fractures were known as common fracture site because of morphological anatomic structure. The mandibular third molar appears to be the most frequent impacted tooth. The mandibular third molar have influence on mandibular angle fractures according to it's eruption state. Also, the mandibular angle fracture including the third molar may influence on post operative infection whether the third molar is in impacted or extracted state when reduction of fracture site is operated. The presence or absence and degree of impaction of the mandibular third molar were assessed for each patient and were related to the occurrence of the mandibular angle fracture. The extraction or non extraction of the mandibular third molar were related to the occurrence of the post operative infection in the reduction of mandibular angle fractures. In the presence of mandibular third molar, the possibility of mandibular angle fractures were relatively common. When viewing the mandibular third molar at occlusal plane, the possibility of mandibular angle fractures were high in the class C group. The possibility of mandibular angle fractures were high in the mesial angulation and partial impaction. There was a statistically significant difference(P<0.05). In complete erupted mandibular third molar, the possibility of post operative infection occurs quite often, but there was no statistical significant difference(P>0.05). In the extracted or non extracted of mandibular third molar, the post operative infection showed no statistical significant difference(P>0.05). With the results mentioned above, mandibular third molar was significantly more susceptible to mandibular angle fracture. In the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

• The Journal of Advanced Prosthodontics
• /
• 제8권6호
• /
• pp.489-493
• /
• 2016

PURPOSE. This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS. Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to $45^{\circ}$ oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (${\alpha}=.05$). RESULTS. The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION. For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제18권4호
• /
• pp.712-717
• /
• 1996

The term osteomyelitis literally means inflammation of bone marrow. It is described as an inflammatory condition of bone primarily engaging the medullary cavity extending to the periosteum. Following circulatory collapse and ischemia, the involved portions of the bone become necrotic. Cellulitis and osteomyelitis are the most frequent complications of fractures of the mandible and maxilla, because there is an abscessed tooth in the line of fracture. Since most fractures are compound fractures, infection may develop because of contact with oral secretions or outside air. The treatment of chronic osteomyelitis is still under debate. Some authors rely on antibiotics alone, while others advocate combination with surgery. But when infection occurs, establish proper drainage and administer antibiotics. Author treated a case of infected mandibular fracture with mandibular osteotomy, sequestrectomy, iliac bone graft and hyperbaric oxygen therapy, who had suffered suppurative osteomyelitis and mandibular nonunion following the open reduction of the mandibular fracture.

• The Journal of Advanced Prosthodontics
• /
• 제10권4호
• /
• pp.300-307
• /
• 2018

PURPOSE. To investigate the fatigue and fracture resistance of computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic molar crowns on dental implants and human teeth. MATERIALS AND METHODS. Molar crowns (n=48; n=8/group) were fabricated of a lithium-disilicate-strengthened lithium aluminosilicate glass ceramic (N). Surfaces were polished (P) or glazed (G). Crowns were tested on human teeth (T) and implant-abutment analogues (I) simulating a chairside (C, crown bonded to abutment) or labside (L, screw channel) procedure for implant groups. Polished/glazed lithium disilicate (E) crowns (n=16) served as reference. Combined thermal cycling and mechanical loading (TC: $3000{\times}5^{\circ}C/3000{\times}55^{\circ}C$; ML: $1.2{\time}10^6$ cycles, 50 N) with antagonistic human molars (groups T) and steatite spheres (groups I) was performed under a chewing simulator. TCML crowns were then analyzed for failures (optical microscopy, SEM) and fracture force was determined. Data were statistically analyzed (Kolmogorow-Smirnov, one-way-ANOVA, post-hoc Bonferroni, ${\alpha}=.05$). RESULTS. All crowns survived TCML and showed small traces of wear. In human teeth groups, fracture forces of N crowns varied between $1214{\pm}293N$ (NPT) and $1324{\pm}498N$ (NGT), differing significantly ($P{\leq}.003$) from the polished reference EPT ($2044{\pm}302N$). Fracture forces in implant groups varied between $934{\pm}154N$ (NGI_L) and $1782{\pm}153N$ (NPI_C), providing higher values for the respective chairside crowns. Differences between polishing and glazing were not significant ($P{\geq}.066$) between crowns of identical materials and abutment support. CONCLUSION. Fracture resistance was influenced by the ceramic material, and partly by the tooth or implant situation and the clinical procedure (chairside/labside). Type of surface finish (polishing/glazing) had no significant influence. Clinical survival of the new glass ceramic may be comparable to lithium disilicate.

• 대한두개안면성형외과학회지
• /
• 제20권6호
• /
• pp.376-381
• /
• 2019

Background: This study was conducted to determine the relationship between third molar (M3) and mandibular fracture. Methods: Patients with unilateral mandibular angle or condyle fractures between 2008 and 2018 were evaluated retrospectively. Medical records were reviewed regarding the location of fractures, and panoramic radiographs were reviewed to discern the presence and position of ipsilateral mandibular third molars (M3). We measured the bony area of the mandibular angle (area A) and the bony area occupied by the M3 (area B) to calculate the true mandibular angle bony area ratio (area A-B/area A×100). Results: The study consisted of 129 patients, of which 60 (46.5%) had angle fractures and 69 (53.5%) had condyle fractures. The risk of angle fracture was higher in the presence of M3 (odds ratio [OR], 2.2; p< 0.05) and the risk of condyle fracture was lower in the presence of M3 (OR, 0.45; p< 0.05), than in the absence of M3. The risk of angle fracture was higher in the presence of an impacted M3 (OR, 0.3; p< 0.001) and the risk of condyle fracture was lower in the presence of an impacted M3 (OR, 3.32; p< 0.001), than in the presence of a fully erupted M3. True mandibular angle bony area ratio was significantly lower in the angle fractures than in the condyle fractures (p= 0.003). Conclusion: Angle fractures had significantly lower true mandibular angle bony area ratios than condyle fractures. True mandibular angle bony area ratio, a simple and inexpensive method, could be an option to predict the mandibular fracture patterns.

• 대한치과보철학회지
• /
• 제45권3호
• /
• pp.295-302
• /
• 2007

Statement of problem. Fracture of the tooth-colored superstructure material is one of the main prosthetic complications in implant-supported prostheses. Purpose. The purpose of this in vitro study was to compare the fracture strength between the cement-retained implant-supported metal-ceramic crowns and the indirect composite resinveneered metal crowns under the vertical compressive load. Material and methods. Standard implants of external type (AVANA IFR 415 Pre-mount; Osstem Co., Busan, Korea) were embedded in stainless steel blocks perpendicular to their long axis. Customized abutments were fabricated using plastic UCLA abutments (Esthetic plastic cylinder; Osstem Co., Busan, Korea). Thirty standardized copings were cast with non-precious metal (Rexillium III, Pentron, Walling ford, Conn., USA). Copings were divided into two groups of 15 specimens each (n = 15). For Group I specimens, metal-ceramic crowns were fabricated. For Group II specimens, composite resin-veneered (Sinfony, 3M-ESPE, St. Paul, MN, USA) metal crowns (Sinfony-veneered crowns) were fabricated according to manufacturer's instructions. All crowns were temporary cemented and vertically loaded with an Instron universal testing machine (Instron 3366, Instron Corp., Norwood, MA, USA). The maximum load value (N) at the moment of complete failure was recorded and all data were statistically analyzed by independent sample t-test at the significance level of 0.05. The modes of failure were also investigated with visual analysis. Results. The fracture strength of Sinfony-veneered crowns ($2292.7{\pm}576.0N$) was significantly greater than that of metal-ceramic crowns ($1150.6{\pm}268.2N$) (P < 0.05). With regard to the failure mode, Sinfony-veneered crowns exhibited adhesive failure, while metal-ceramic crowns tended to fracture in a manner that resulted in combined failure. Conclusion. Sinfony-veneered crowns demonstrated a significantly higher fracture strength than that of metal-ceramic crowns in cement-retained implant-supported prostheses.

• 대한치과보철학회지
• /
• 제56권4호
• /
• pp.384-390
• /
• 2018

치주적으로 지지가 불리한 소수의 잔존치가 남은 환자에게 있어 하이브리드 텔레스코픽형 이중관의치는 장기적으로 안정적인 예후를 보이는 치료가 된다. 편측 악궁에 소수 잔존치가 남고 반대측 악궁에 다수의 자연치가 존재 하는 경우 임플란트를 식립하여 자연치와 혼재된 형태의 이중관 의치를 제작 할 시 의치의 지지 및 안정요소의 향상과 더불어 저작력의 균형을 맞추어 줄 수 있게 된다. 본 증례는 55세 여자 환자로 만성 치주염으로 인해 치주 지지가 감소한 소수 잔존치 상태에서 자연치만으로 하이브리드 텔레스코픽형 이중관 의치 치료를 통해 9.5년간 의치를 사용하였다. 9.5년 후 지대치 파절로 내원 하여 임플란트의 식립을 통해 자연치와 임플란트가 혼재된 하이브리드 텔레스코픽형 이중관 의치로 재수 복 하였으며, 이를 통해 재 치료에서도 장기적 예후의 안정성을 기대 할 수 있다.