• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.37.1-37.11
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• 2021

Objectives: This systematic review evaluated the efficacy of the supplementary use of the XP-endo Finisher on bacteria content reduction in the root canal system. Materials and Methods: In-vitro studies evaluating the use of the XP-endo Finisher on bacteria content were searched in four databases in July 2020. Two authors independently screened the studies for eligibility. Data were extracted, and risk of bias was assessed. Data were meta-analyzed by using random-effects model to compare the effect of the supplementary use (experimental) or not (control) of the XP-endo Finisher on bacteria counting reduction, and results from different endodontic protocols were combined. Four studies met the inclusion criteria while 1 study was excluded from the meta-analysis due to its high risk of bias and outlier data. The 3 studies that made it to the meta-analysis had an unclear risk of bias for at least one criterion. Results: No heterogeneity was observed among the results of the studies included in the meta-analysis. The study excluded from the meta-analysis assessing the bacteria counting deep in the dentin demonstrated further bacteria reduction upon the use of the XP-endo Finisher. Conclusions: This systematic review found no evidence supporting the supplementary use of the XP-endo Finisher on further bacteria counting the reduction in the root canal.

• The Journal of Advanced Prosthodontics
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• 제3권3호
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• pp.119-125
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• 2011

PURPOSE. The aim of this study was to evaluate the influence of resin cement thickness on the microtensile bond strength between zirconium-oxide ceramic and resin cement. MATERIALS AND METHODS. Thirty-two freshly extracted molars were transversely sectioned at the deep dentin level and bonded to air-abraded zirconium oxide ceramic disks. The specimens were divided into 8 groups based on the experimental conditions (cement type: Rely X UniCem or Panavia F 2.0, cement thickness: 40 or 160 ${\mu}m$, storage: thermocycled or not). They were cut into microbeams and stored in $37^{\circ}C$ distilled water for 24 h. Microbeams of non-thermocycled specimens were submitted to a microtensile test, whereas those of thermocycled groups were thermally cycled for 18,000 times immediately before the microtensile test. Three-way ANOVA and Sheffe's post hoc tests were used for statistical analysis (${\alpha}$=95%). RESULTS. All failures occurred at the resin-zirconia interface. Thermocycled groups showed lower microtensile bond strength than non-thermocycled groups (P<.001). Differences in cement thickness did not influence the resin-zirconia microtensile bond strength given the same resin cement or storage conditions (P>.05). The number of adhesive failures increased after thermocycling in all experimental conditions. No cohesive failure was observed in any experimental group. CONCLUSION. When resin cements of adhesive monomers are applied over air-abraded zirconia restorations, the degree of fit does not influence the resin-zirconia microtensile bond strength.

• Restorative Dentistry and Endodontics
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• 제26권4호
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• pp.316-325
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• 2001

The purpose of this study was to evaluate the effect of adhesive curing timing on the direction of polymerization shrinkage of light-curing composite resin. In this study, the curing times of adhesive and composite resin were measured by differential scanning calorimeter(DSC). 28 extracted human molars were embedded in clear resin and box-type cavities were prepared. Based on DSC data, the experimental teeth were divided into 4 groups. Group 1: no bond; Group 2: late curing; Group 3: Intermediate curing; Group 4: Early curing. After treating with adhesive, the buccal cavities were filled with Z-100 hybrid composite resin and the lingual ones were filled with AEliteflo flowable composite resin. The depressions at the surface were measured by surface profilometer, then the specimens were embedded in clear resin and sectioned. Impressions were obtained and used to get epoxy resin replicas. The epoxy replicas were gold-coated and observed under SEM. Average Maximum Gap(AMG), Gap Proportion(GP), Average Marginal Index(AMI) were used to compare the shrinkage gap of each group. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA, Student-Newman-Keuls method. The results of this study were as follows. 1. Average Maximum Gap, Gap Proportion, Average Marginal Index and depression at the surface or Z-100 hybride composite resin were smaller than those of AEliteflo flowable composite resin(P<0.05). 2. When the bonding between composite resin and tooth structure was strong, the shrinkage gap was small, and depression at the surface was deep(P<0.05). 3. In the well-bonded group, light-curing composite resin shrank toward bonded cavity wall, not toward light source. The result suggested that the direction of polymerization shrinkage was affected by the quality of bonding in the dentin-resin interface. The strong was the bonding between composite resin and tooth structure, the smaller was the gap and the deeper was the depression at the surface. Then the flow to compensate the polymerization shrinkage proceeded from surface to bonded cavity wall.

• 대한치과교정학회지
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• 제24권2호
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• pp.303-317
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• 1994

치아이동시 발생되는 치근 흡수에 관련된 특이면역반응의 역할을 연구하기 위해 치근 흡수에 따른 치근항체의 역가 변화를 관찰하였다. 생후 2년된 성견 다섯마리를 실험동물로 사용하였다. closed coil spring을 사용하여 각 실험동물의 상악 6전치에 200-250gm의 함입력을 가하였으며, 하악 6전치를 발거하여 동종항원으로 사용하였다. 발거된 하악 전치의 상아질 부위를 분리하여 6M Guanidine-HCl-10% EDTA(pH 5.0)에서 해리시킨 다음 부유물 만을 투석하여 항원을 준비하였다. 치아를 함입시키기 전 1회 혈청을 채취하고 함입시키면서 매주 간격으로 11회 형철을 채취하였다. 실험 9주째 치근 흡수가 일어나고 있는 상악 6전치를 모두 발거하여 항원의 근원을 제거하였다. 혈청 내 치근항체의 역가는 ELISA(enzyme-linked immunosorbent assay)로 측정하였다. 항체 특이성에 대한 대조군으로 혈청과 치근 항원 그리고 혈청과 관련없는 박테리아 항원(Porphyro monas gingivalis 33277)을 섭씨 25도에서 3시간 반응시켜 모든 과정에서 항원-항체 반응을 측정하였다. 치근 흡수를 관찰하기 위하여 실험 전과 실험 후 한 달 간격으로 방사선 교합사진을 촬영하였고 9주째 발거한 치아의 치근단 부위를 입체현미경으로 관찰하였다. 치근항원에 대한 자가항원의 역가 변화를 측정하여 다음과 같은 결과를 얻었다. 자가항체의 역가는 치아가 함입되면서 즉시 감소하였다가 1주후 다시 증가하였으며 4주째 최고수준에 도달한 다음 다시 지속적으로 감소하였다. 흡수 중인 치근을 발거한 직후 급격히 증가하는 양상을 보였다. 치근 항원과 반응시킨 혈청내에서는 항원-항체 반응이 거의 나타나지 않았으며 관련없는 박테리아 항원과 반응을 시킨 혈청에서는 활성도가 동종 치근 항원에 대한 자가항체의 활성도와 비슷하게 나타났다. 방사선 교합사진 상에서는 육안으로 구별할 수 있는 차이가 거의 없었으나 입체현미경하에서는 치근단 부위의 다양한 흡수 양상을 관찰할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제33권6호
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• pp.499-506
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• 2008

이 연구는 다양한 접착시스템을 사용하는 6가지 레진시멘트를 이용하여 근관에 합착한 섬유포스트를 push-out 검사에 의해 포스트와 치근 상아질 간의 결합강도를 상호 비교하기 위하여 시행되었다. 발거된 하악 소구치의 치관부를 제거하고 치근부를 근관충전한 후 9mm의 포스트 룸을 형성하였다. 사용된 레진시멘트의 종류에 따라서 무작위로 6개씩 선택하여 Duo-Link 군, Variolink II 군, Panavia F 군, Multilink Automix 군, RelyX Unicem 군, Maxcem 군으로 분류하였다. 제조사의 지시에 따라서 각각의 레진시멘트를 Uni-dose needle tip을 이용하여 근단부에서부터 주입하여 광투과성 섬유 포스트인 no. 2 DT Light Post를 근관에 합착하였다. 증류수에 24시간동안 보관한 후, 주수 하에 저속의 Diamond Wheel Saw를 이용하여 각 치근을 횡단면으로 1mm 두께로 절단하여 연속적인 절편 6개를 얻었다. 각 군의 시편을 universal testing machine에 고정하고 push-out 검사를 시행하여 push-out 강도를 통계 분석한 결과, 서로 다른 접착시스템을 사용한 레진시멘트 군간의 push-out 강도는 유의한 차이가 나타나지 않았다 (p > 0.05).

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.247-251
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• 2001

;A dental developmental anomaly is defined as an isolated aberration in tooth form, caused by a disturbance or abnormality which occurred during tooth development. There are numerous types of dental anomalies, and a considerable variation in the extent of the defects occurs with each type. Teeth with these anomalies pose unique challenges. Since the defects are not always apparent clinically, they can confuse diagnosticians investigating the etiology of pulpal pathosis. When endodontic treatment is required, the defects often hinder access cavity preparation and canal instrumentation. Treatment planning also becomes more challenging, since the defects can create complicated periodontal problems, and the malformed teeth can be difficult to restore, particularly those weakened by endodontic therapy. Fusion is defined as the joining of two developing tooth germs resulting in a single large tooth structure. The incidence of fusion is < 1% in the Caucasian population, and it is believed that physical force or pressure produces contact of the developing teeth. Clinically and radiographically, a fused tooth usually appears as one large crown with at least partially separated roots and root canals. There may be a vertical groove in the tooth crown delineating the originally separate crowns. Dens invaginatus is a deep surface invagination of the crown or root that is lined by enamel. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisor is the tooth most commonly involved. Studies have revealed an incidence ranging from 0.25% to as high as 10%. The invagination ranges from a slight pitting to an anomaly occupying most of the crown and root. The invagination frequently communicates with the oral cavity, allowing the entry of irritants and microorganism either directly into pulpal tissues or into an area that is deparated from pulpal tissues by only a thin layer of enamel and dentin. This continuous ingress of irritants and the subsequent inflammation usually lead to necrosis of the adjacent pulp tissue and then to periapical or periodontal abscesses. If the invagination extends from the crown to the periradicular tissue and has no communication with the root canal system, the pulp may remain vital. Recommended treatment of fused tooth and dens invaginatus has been reported in the endodontic literature. This case report describes the endodontic treatment of a maxillary laterl incisors having fused crown and dens invaginatus.natus.

• 대한소아치과학회지
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• 제39권1호
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• pp.58-65
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• 2012

치관-치근 파절은 법랑질, 상아질, 백악질이 모두 포함된 치아의 파절로, 파절선이 대부분 절단연이나 순측의 변연부 치은에서 구개측 치은열구 하방으로 사선으로 진행된다. 파절선의 위치가 치은 연상이라면 파절편의 제거 및 치은연상 수복을 시행하고, 치은 연하라면 파절면의 외과적 노출술, 교정적 정출술, 외과적 정출술을 이용한 치아의 수복이 이루어진다. 그 외에 섬유 강화형 포스트를 삽입하여 치관 수복물의 유지력을 높이고, 레진 접착 시스템을 사용하여 치관 파절편을 재부착함으로써 생물학적으로 최소한으로 침습적인 치료를 하는 방법도 있다. 만약 파절의 정도가 치은 연하로 깊은 경우 발치나 치관절제술을 이용한 치근의 유지 등을 고려할 수 있다. 본 증례는 치관-치근파절로 내원한 12세 환아로 섬유강화형 포스트를 사용하여 치관 파절편 재부착을 시행하였으며 양호한 경과를 보여 이를 보고하는 바이다.

• 대한치과교정학회지
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• 제20권3호
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• pp.447-462
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• 1990

The objective of this experiment is to observe structural differences in the othodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12 Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results w ere examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root sulfate. From the results of the study, the following conclusions may be drawn: The root resolution and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resolution of endodontically and vital teeth when both were subjected to orthodontic forces.

• Restorative Dentistry and Endodontics
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• 제34권2호
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• pp.103-112
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• 2009

본 연구에서는 2종의 이원중합 레진시멘트 (RelyX ARC와 Variolink II)를 이용하여 접착제와 레진시멘트의 중합방법 (자가중합과 광중합)이 섬유포스트와 근관 상아질의 결합강도와 접착계면에 미치는 영향을 상호 비교하기 위하여 시행하였다. 단근관을 갖는 발거된 32개의 하악 소구치에 근관을 충전한 후, FRC Postec system의 Reamer로 9 mm 깊이의 포스트 공간을 형성하였다. 레진시멘트의 종류와 중합방법에 따라 4개의 군 (R-SC군, R-LC군, V-SC군, V-LC군)으로 분류하였다. 포스트 공간에 각 군의 접착제를 도포한 후 레진시멘트를 주입하고, No. 3 FRC Postec 포스트를 위치시켜 자가중합 또는 광중합시켰다. 각 군의 치근을 실온의 증류수에 24시간동안 보관한 다음, 저속의 diamond wheel saw를 이용하여 치관부에서 치근단부를 향해 1.5 mm두께로 연속적으로 횡절단하여 1개의 치근에서 3개의 절편을 얻었다. 각 군의 절편 (31개)은 만능시험기에서 push-out 검사를 시행하였고, 각 군의 강도 값은 반복측정 two-way ANOVA와 one-way ANOVA를 이용하여 비교 분석하였다. 각 군의 절편 (3개)은 주사전자현미경하에서 섬유포스트, 레진시멘트 및 치근 상아질 간의 계면을 관찰, 비교하였다. 본 연구의 결과 전 부식 레진시멘트를 이용하여 섬유포스트를 포스트 공간에 합착할 경우, 접착제와 레진시멘트의 중합방법은 근관 상아질의 결합강도에 영향을 주었으며, 광중합보다 자가중합 방법 이 우수한 결합강도와 계면을 나타내었다.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.451-469
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• 1996

The purpose of this study was to investigate the effect of calcium hydroxide and glass ionomer cement fillings on the levels of $LTB_4$ and $LTC_4$ in experimentally inflamed rat dental pulp. The dental pulp in the mandibular incisor of wistar rat was irritated by cutting a 5mm deep hole in the dentin with a twist drill bur of 0.5mm diameter, without cooling. The cavities were filled with calcium hydroxide(light-cured) and glass ionomer cement(light cured). The untreated pulp served as control tissue specimen. After cavity preparations, the rat with or without various treatment were sacrificed in various time by decapitation. The dental pulp tissue were carefully removed and the concentrations of $LTB_4$ and $LTC_4$ were determined by radioimmunoassay. And pulps were examined histologically to observe inflammatory feature. The result were obtained as follows : 1. The inflammatory features of pulps were observed microscopically in all experimental groups. And degree of inflammation was decreased with time. 2. The concentrations of $LTB_4$ and $LTC_4$ for all experimental groups were significantly higher than those for control group 6 hours after cavity preparation(p<0.05). 3. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 6 hours after cavity preparation. In the concentrations of $LTB_4$, significant differences among 3 groups were noted(p<0.05). 4. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 24 hours after cavity preparation. And there were statistically significant difference in concentrations of $LTB_4$ between the group of irritation and the group filled with calcium hydroxide(p<0.05). 5. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 48 hours after cavity preparation. But no statistically difference was found (p>0.05). 6. The concentrations of $LTB_4$ and $LTC_4$ in all experimental groups were highest level at 6 hour after experiment and decreased as time progresses(correlation coefficient>0.8).