Effect of surface defects and cross-sectional configuration on the fatigue fracture of NiTi rotary files under cyclic loading

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files (K3^(TM), ProFile^(®), and HERO 642^(®)) with #30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups: control (no surface defects) and experimental group (artificial surface defects). A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the K3^(TM) (p<0.05). There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic pat-terns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.ope

The Degree and Incidence of interappointment pain associated with clinical factors after canal enlargement

치의학과/석사[영문] [한글] 근관성형후 나타나는 술후 동통의 빈도 및 정도가 사용약제 및 제반 임상요소들과 상관 성이 있는가를 알아보기 위해 연세대학교 치과대학 부속병원 보존과에 내원한 환자중 증 상이 없는 256명, 260개의 치아를 대상으로 내원 당일 근관내에 한정하여 무균 상태하에 근관성형을 시행하고 치료 2∼10일후 환자를 재 내원시켜 질문서 및 임상적 검사를 토대 로 치료된 치아와 관련된 여러 임상요소들 즉 치수생촬력, 치근단병소, 연령, 전·구치, 응급처치, 성별, 상·하악별, 교합면 삭제, 누공 및 사용약제에 따른 술후 동통의 빈도(p ain/no pain) 및 정도(none/slight/moderate to severe)와의 상관성을통계학적으로 비교 분석하여 다음의 결과를 얻었다. 1. 술후 동퉁과 연관시켜 분석한 여러 임상요소들 즉 치수생활력 유무, 응급처치 여부, 치근단병소 유무, 상·하악별, 전·구치별, 연령별, 성별 및 교합면삭제 여부와는 통계 학적 유의성을 보이지 않았다(p>.05). 2. 치근단병소와 연관되어 누공이 형성된 경우는 근관성형후 동통은 적게 나타났으며 이는 퉁계학적으로 유의성이 있었다(p<.05). 3. 근관소독제 및 세척제의 올바른 임상적 사용은 술후 동통의 빈도나 정도에 영향을 미치지 않았다. THE DEGREE AND INCIDENCE OF INTERAPPOINTMENT PAIN ASSOCIATED WITH CLINICAL FACTORS AFTER CANAL ENLARGEMENT Kee Yeon Kum, D.D.S. Department of Dental Science, Graduate School, Yonsei Uniersity (Directed by Associate Professor Dong Soo Pack, D.D.S., M.S.D., Ph.D.) The purpose of this study was to determine whether any clinical factors or conditions are associated with an increased incidence or degree of pain occurring during endodontic treatment in patients who begin treatment with no symptoms. The 260 teeth of 256 patients were surveyed and statistical analysis was used to determine whether a significant relationship existed between pain and any recorded clinical factors or conditions. The following conclusions were drawn. 1. No significant relationship between interappointment pain and any of the analyzed clinical factors or conditions except for fistula formation could be determined. 2. The presence of a draining fistula from a periapical lesion significantly decreased the posttreatment pain. 3. The judicious use of canal irrigants and canal medicaments is not associated with an increased incidence or degree of interappointment pain.restrictio

(The) effect of four kinds of acid and concentration on the formation of artificial carious lesion in human tooth enamel

치의학과/박사[한글] 치아탈회는 치태내 세균의 대사과정에서 생산된 유기산에 의하여 야기되는 일련의 과정으로써, 치아면에서 집락을 형성하는 세균들의 종류와 상대적인 양뿐만 아니라 법랑질의 화학적 특성을 포함하는 매우 역동적인 현상으로 이해되고 있다. 이러한 초기 치아우식은 건전한 표면층 하방에 광물질 소실이 일어나는 표층하 병소가 형성되기 때문에 단순한 탈회작용으로는 설명하기 어려운 특징을 가지고 있다. 건전표층 하방에 우식 표면하층이 형성되는 현상에 대하여 표면 법랑질 자체의 화학적 특성이나 억제인자 및 pellicle의 존재 흑은 탈회와 재침착 사이에서 발생하는 동역학적인 기전으로 설명하고 있으며, 이러한 법랑질 탈회는 탈회용액의 무기질 농도, 포화도,pH, 탈회시간, 유기산의 고유한 산해리 상수 및 비이온화된 형태의 농도, 법랑질의조직학적 구조 등에 영향을 받는다고 알려져 있다. 본 연구는 plaque fluid를 구성하고 있는 주요 유기산인 lactic, acetic, succinic, propionic acid 들이 초기 우식병소의 조직학적인 특징인 우식 표면하층의 생성과 진행에 미치는 상대적인 영향을 평가하고자 하였다. 이에 탈회나 균열이 없는 160개의 치아를 대상으로 100 ㎛두께의 치아 연마표본을 제작하고 건전한 법랑질 부위에 3 mm의 window를 형성한 후 pH와 포화도를 고정시키고 lactic acid, acetic acid, propionic acid, succinic acid의 농도를 각각 10 mM,25 mM, 50 mM,100 mM로 변화시킨 완충용액을 제조하고 1일, 2일, 3일간 탈회시간을 달리하여 25℃ 항온조에 담가 두었다가 편광현미경으로 이를 관찰하고 그 진행 정도를 평가하여 다음과 같은 결과를 얻었다. 1. 편광현미경을 이용하여 물을 침윤시켜 관찰한 결과 건전표층과 정상법랑질은 음성복굴절(negative birefringence)을, 병소본체는 양성복굴절(positive birefringence)을 나타내었다. 2. 각 유기산의 농도가 높아질수록 법랑질의 탈회속도가 빨랐다. 3. 표층하 탈회의 병소깊이는 lactic acid, acetic acid, propionic acid, succinic acid 순으로 증가하였다. 4. pH와 포화도를 일정하게 하였을 때 유기산의 농도가 법랑질의 탈회속도에 영향을 주었다. 이상의 결과로 초기 법랑질 우식병소 형성에 있어 pH나 포화도 외에 유기산의 농도도 독립적으로 법랑질 탈회에 관여하는 것으로 생각되며 그 외에 법랑질 탈회에 관여하는 인자들에 대한 다각적인 연구를 통하여 우식발생을 조기에 차단할 수 있는 효과적인 우식예방법의 개발이 필요하리라 사료된다. THE EFFECT OF FOUR KINDS OF ACID AND CONCENTRATION ON THE FORMATION OF ARTIFICIAL CARI0US LESI0N IN HUMAN T00TH ENAMEL Kee Yeon Kum, D.D.S., M.S.D, Department of Dentistry, The Graduated School, Yonsei University (Directed by Professor Chan Yong Lee D.D.S., M.S.D., D.D.Sc.) The end products of the metabolism of the oral microorganism, organic acids, are an element that produces dental caries. Four organic acid in plaque fluid, lactic acid, acetic acid, propionic acid, propionic acid which take the important role in producing dental caries, were chosen to evaluate the effect of acid type and concentration. The subject,100㎛ in thickness, were immersed in acid-buffer solution which has the different acid concentration of 10mM, 25mM, 50mM, 100mM and pH 4.3 and degree of saturation was 0.153±0.003 kept in constant and were operated to produce artificial caries under different demineralization time (1, 2, 3 day) at x25. The results were obtained by observing under polarizing microscope at x25. 1. The subsurface lesion, specific finding of incipient enamel caries, showed positive birefringence. but surface 97ne and sound enamel showed negative birefringence. 2. The demineralization rate of enamel was increased as the acid concentration increased. 3. The subsurface lesion showed increasing depth in the order of lactic, acetic, propionic acid, succinic acid. 4. The concentration of organic acid in artificial caries system had an independent effect on demineralization rate in enamel under the constant pH and degree of saturation. The result of this study showed that not only pH and the acid strength but the concentration of organic acid had an independent effect on demineralization rate in early enamel caries. And through the further research on the factors influencing enamel demineralization, it will be necessary to develop an effective caries preventive therapy. [영문] The end products of the metabolism of the oral microorganism, organic acids, are an element that produces dental caries. Four organic acid in plaque fluid, lactic acid, acetic acid, propionic acid, propionic acid which take the important role in producing dental caries, were chosen to evaluate the effect of acid type and concentration. The subject,100㎛ in thickness, were immersed in acid-buffer solution which has the different acid concentration of 10mM, 25mM, 50mM, 100mM and pH 4.3 and degree of saturation was 0.153±0.003 kept in constant and were operated to produce artificial caries under different demineralization time (1, 2, 3 day) at x25. The results were obtained by observing under polarizing microscope at x25. 1. The subsurface lesion, specific finding of incipient enamel caries, showed positive birefringence. but surface 97ne and sound enamel showed negative birefringence. 2. The demineralization rate of enamel was increased as the acid concentration increased. 3. The subsurface lesion showed increasing depth in the order of lactic, acetic, propionic acid, succinic acid. 4. The concentration of organic acid in artificial caries system had an independent effect on demineralization rate in enamel under the constant pH and degree of saturation. The result of this study showed that not only pH and the acid strength but the concentration of organic acid had an independent effect on demineralization rate in early enamel caries. And through the further research on the factors influencing enamel demineralization, it will be necessary to develop an effective caries preventive therapy.restrictio

The Effect of Surface Defects on the Cyclic Fatigue Fracture of HEROShaper Ni-Ti rotary files in a Dynamic Model : A Fractographic Analysis

This in vitro study examined the effect of surface defects on cutting blades on the extent of the cyclic fatigue fracture of HEROShaper Ni-Ti rotary files using fractographic analysis of the fractured surfaces. A total of 45 HEROShaper (MicroMega) Ni-Ti rotary flies with a #30/.04 taper were divided into three groups of 15 each. Group 1 contained new HEROShapers without any surface defects. Group 2 contained HEROShapers with manufacturing defects such as metal rollover and machining marks. Croup 3 contained HEROShapers that had been clinically used for the canal preparation of 4-6 molars A fatigue-testing device was designed to allow cyclic tension and compressive stress on the tip of the instrument whilst maintaining similar conditions to those experienced in a clinic. The level of fatigue fracture time was measured using a computer connected the system. Statistical analysis was performed using a Tukey's test. Scanning electron microscopy (SEM) was used for fractographic analysis of the fractured surfaces. The fatigue fracture time between groups 1 and 2, and between groups 1 and 3 was significantly different (p0.05). A low magnification SEM views show brittle fracture as the main initial failure mode At higher magnification, the brittle fracture region showed clusters of fatigue striations and a large number of secondary cracks. These fractures typically led to a central region of catastrophic ductile failure. Qualitatively, the ductile fracture region was characterized by the formation of microvoids and dimpling. The fractured surfaces of the HEROShapers in groups 2 and 3 were always associated with pre-existing surface defects.ope

IN VITRO EVALUATION OF ACCURACY AND CONSISTENCY OF FOUR DIFFERENT ELECTRONIC APEX LOCATORS

이번 연구는 서로 다른 4개의 전자근관장측정기의 정확성을 측정하고 각각 0.5지점과 Apex지점에서의 일관성을 비교하고자 하였다. 40개의 발치된 상하악 소구치를 대상으로 치수강 개방 후 alginate model에 고정시키고 근관장을 측정하였다. 사용된 전자근관장측정기는 Root ZX (Morita, Tokyo, Japan), SmarPex (META, Seoul, Korea), Elements Diagnostic Unit (SybronEndo, CA, USA), E-Magic Finder Deluxe (S-Denti, Seoul, Korea)이다. 먼저 모든 치아에서 4개의 전자근관장측정기를 사용하여 0.5지점과 Apex지점에서 근관장을 측정하여 한 치아당 8개의 측정값을 얻었다. 다음으로 치아를 각 전자근관장측정기당 10개씩 4개의 그룹으로 나누어, 각각 제조사의 지시대로 Root ZX, Elements Diagnostic Unit 및 E-Magic Finder Deluxe는 "0.5"지점에서, SmarPex는 ''Apex" 지점에서 file을 치아에 cement로 고정시켰다. 이후 치근단부 4 mm를 삭제하여 100배율의 Image ProPlus로 관찰하여 file 끝에서 주근단공의 외연까지의 실제거리를 측정한 후, 4개의 전자근관장측정기의 0.5지점 및 Apex지점에서 file 끝과 주근단공 사이의 거리를 계산하여 비교하였다. 그 결과 Root ZX와 E-Magic Finder는 실험군 100%, SmarPex는 90%, Elements Diagnostic Unit는 70��에서 주근단공과의 거리가 임상적 허용범위인 토0.5 mm 이내에 있었다. 또한 각 전자근관장측정기마다 0.5지점과 Apex지점에서의 근관장의 표준편차와 사분위 범위를 구하여 두 지점간의 일관성을 비교한 결과, Root ZX, E-Magic Finder는 0.5지점과 Apex지점에서 비슷한 일관성을 보였으며 SmarPex와 Elements Diagnostic unit는 Apex지점에서 0.5지점보다 더 높은 일관성을 보였다. 전자근관장측정기는 근관 내의 조건에 관계없이 근첨협착부에서 항상 일정한 거리를 재현해 낼 수 있는 일관성이 중요하므로, 이렇게 0.5지점 또는 Apex지점에서의 일관성이 증명된다면 실제 임상에서 사용할 때 전자근관장에서 일정한 거리를 가감하여 사용할 수 있다

Apical anatomy in mesial and mesiobuccal roots of permanent first molars

The purpose of this in vitro study was to investigate the canal configuration types, and the prevalence and location of anatomical variations in the mesiobuccal (MB) and mesial roots of permanent maxillary and mandibular first molars after instrumentation. The number and the type of canals were determined before instrumentation using conventional methods. All root canals from the 47 MB roots and 42 mesial roots were then instrumented to size #30 with ProFile .04 taper rotary instruments in a crown-down method and then filled with a single gutta-percha cone and sealer. Transverse 1 mm-thick cross-sections at 2, 3, 4, and 5 mm from the apex were obtained, stained and examined using a stereomicroscope. The canal configuration types and the prevalence and location of isthmi and accessory canals in roots with two canals were evaluated. The prevalence of two canals was 80.8% in the maxillary MB roots and 95.2% in the mandibular mesial roots. There were six types of canal configurations in the instrumented root apices. The prevalence of anatomical variations was highest at the apical 4 mm level, and was more frequent in mandibular first molars, and in roots with Weine type III canal. chi test showed that the prevalence of the anatomical variations was statistically higher in the maxillary MB roots with Weine type III canals than in those with Weine type II canals (p < 0.05). Different canal configurations were often found at different levels in the same root. The results indicate that anatomical variations persist following instrumentation of roots with two canals in first molars. These anatomical variations should be considered during surgical or nonsurgical endodontic procedures of the permanent first molars.restrictio

반복 굽힘 스트레스 하에서 전동식 니켈-티타늄 파일의 단면적의 크기가 피로파절에 미치는 영향 : 파절역학 분석

본 연구의 목적은 니켈 티타늄 전동파일의 피로 파절에 파일의 단면 형태가 미치는 영향을 평가하고자 하였다. 6 종의 ProFile (Dentsply), Mtwo (VDW), K3 (SybronEndo), Heroshaper (MicroMega), NRT (Mani), Alpha system (KOMET) 니켈-티타늄 전동 파일(ISO 30 size/.04 taper)을 각 10개씩 실험군으로 배정하고 실험을 진행하였다. 니켈 티타늄 전동파일에 반복적인 장력과 압축력을 재현시킬 수 있는 피로파절 실험기(Denbotix)와 연결된 토크 조절 전동모터(Aseptico)에 각 군의 파일을 연결하여 300rpm 속도로 만곡도가 60도이고 5mm의 반경을 가진 인공 금속 근관 내를 6 mm pecking depth로 작동시켰다. 각 파일의 파절시간을 측정하고 통계 분석하여 유의성을 분석하였으며, 각 군의 파절된 모든 파일의 파절면을 주사전자현미경을 이용한 fractographic analysis를 통해 파절 역학을 규명하였다. 또한 각 군에서 3개의 사용하지 않은 새 파일을 clear resin에 매몰하고tip에서부터 3mm 지점을 횡절단하여 Image-Pro Plus (Imagej 1.34n, NIH) 소프트웨어로 절단면의 단면적을 측정하고 단면적의 크기와 피로 파절과의 상관성도 평가하였다. 실험 결과 NRT와 ProFile이 다른 실험군에 비해서 유의성 있게 높은 피로 파절 저항성을 보였다(P < .05). 또한 파일의 단면적은 피로파절 저항성과 통계학적인 유의성은 보이지 않았다. Fractographic analysis 결과 모든 시편에서 파절면은 ductile fracture와 brittle fracture가 혼재된 양상으로 나타났다. 결론적으로 니켈 티타늄 전동 파일의 단면적의 크기는 피로파절 저항과는 상관성이 적었다. This study aimed to assess the influence of different cross-sectional area on the cyclic fatigue fracture of Ni-Ti rotary files using a fatigue tester incorporating cyclical axial movement. Six brands of Ni-Ti rotary files (ISO 30 size with. 04 taper) of 10 each were tested: Alpha system (KOMET), HeroShaper (MicroMega), K3 (SybronEndo), Mtwo (VDW), NRT (Mani), and ProFile (Dentsply). A fatigue-tester (Denbotix) was designed to allow cyclic tension and compressive stress on the tip of the instrument. Each file was mounted on a torque controlled motor (Aseptico) using a 1:20 reduction contra-angle and was rotated at 300 rpm with a continuous, 6 mm axial oscillating motion inside an artificial steel canal. The canal had a angle and a 5 mm radius of curvature. Instrument fracture was visually detected and the time until fracture was recorded by a digital stop watch. The data were analyzed statistically. Fractographic analysis of all fractured surfaces was performed to determine the fracture modes using a scanning electron microscope. Cross-sectional area at 3 mm from the tip of 3 unused Ni-Ti instruments for each group was calculated using Image-Pro Plus (Imagej 1.34n, NIH). Results showed that NRT and ProFile had significantly longer time to fracture compared to the other groups (p < .05). The cross-sectional area was not significantly associated with fatigue resistance. Fractographycally, all fractured surfaces demonstrated a combination of ductile and brittle fracture. In conclusion, there was no significant relationship between fatigue resistance and the cross-sectional area of Ni-Ti instruments under experimental conditions.SNUDH Research fun

하악 대구치에서 근관세척방법에 따른 잔사제거효과에 대한 평가

본 연구의 목적은 isthmus가 존재하는 하악 대구치의 근심 근관에서 근관세척방법에 따른 잔사제거효과를 평가하는 것이다. 45개의 하악 대구치의 근심근관을 #30 Profile .06까지 확대하였다. 각 근관을 3개의 군으로 나누고 conventional irrigation syringe와 초음파, RinsEndo를 사용하여 1분간 최종 세척하였다. 조직표본을 제작한 후, 광학현미경으로 치근단 1, 3, 5 mm 부위의 단면을 관찰하였다. 근관과 isthmus의 잔사 양으로 청결도를 계산하고 Mann-Whitney U test로 검정하였다. 1. 초음파 군과 syringe군은 5 mm부위의 isthmus를 제외한 나머지 부위에서 청결도의 유의한 차이가 없었다. 2. RinsEndo군은 syringe군에 비해 1 mm, 3 mm부위의 근관과, 모든 부위의 isthmus에서 유의하게 높은 청결도를 나타내었다 (p<0.05). 3.초음파 군과 RinsEndo군은 3mm부위의 근관을 제외한 나머지 부위에서 청결도의 유의한 차이가 없었다. 임상적으로 RinsEndo를 이용한 근관세척방법의 부가적인 적용이 하악 대구치의 근심근관의 잔사제거에 효과가 있을 것으로 사료된다. The aim of this in vitro study was to evaluate the cleaning efficacy of various irrigation methods in the mandibular mesial roots. The forty five mesial root canals were shaped by Profile .06 instruments to apical size #30 and irrigated with 5ml of 3.5% NaOCl. The teeth were divided into 3 groups and irrigated finally for 1 minute; Group 1: syringe irrigation. Group 2: ultrasonic irrigation. Group 3: RinsEndo irrigation. After histological processing, the cross sections of apical 1, 3, and 5 mm level were examined with an optical microscope. The cleanliness values of canals and isthmuses were calculated and analyzed by Mann-Whitney U test. 1. There were no significant differences in both canal and isthmus cleanliness between syringe irrigation and ultrasonic irrigation except 5 mm level of isthmus. 2. RinsEndo irrigation had significantly higher canal cleanliness values than syringe irrigation at 1 mm and 3 mm levels (p<0.05). Also, RinsEndo irrigation had significantly higher isthmus cleanliness values than syringe irrigation at all levels evaluated (p<0.05). 3. There were no statistical differences in both canal and isthmus cleanliness between ultrasonic irrigation and RinsEndo irrigation except 3 mm level of canal. From this study, RinsEndo irrigation can be useful as an additional irrigation procedure

Evaluation of the prognosis and causes of failure in 182 cases of autogenous tooth transplantation

OBJECTIVES: Autotransplantation is a viable option for treating missing teeth when a donor tooth is available. The aim of this study was to evaluate the prognosis in addition to the causes of failure in 182 autotransplanted teeth. STUDY DESIGN: A total of 182 cases of autotransplantation were analyzed. All the transplants were performed according to a computer-aided rapid prototyping technique with an average extraoral time of 7.58 minutes. These cases were followed for 2 to 60 months after surgery. The prognosis was divided into 4 groups, complete healing, incomplete healing, uncertain healing, and failure. The initial stability, root resorption, and ankylosis were also analyzed. RESULTS: Most transplanted teeth showed complete healing between postoperative 2 months and 8 months. The transplanted teeth with a good initial stability showed better initial healing than those with a poor initial stability. The average extraoral time was 7.58 min (range: immediately after extraction up to 25 min). There was no relationship (P > .05) between the extraoral time and either root resorption (4 cases, 2.4%) or ankylosis (18 cases, 10.7%) within this experimental time period. Nine cases (4.5%) failed. CONCLUSION: This study showed a 4.5% failure rate during the short to intermediate observation period. Autotransplantation is a very useful method for replacing missing teeth, provided that the extraoral time and other factors are well controlled.restrictio

THE ROLE OF TYPE 2 DIABETES AS A PREDISPOSING RISK FACTOR ON THE PULPO-PERIAPICAL PATHOGENESIS: REVIEW ARTICLE

당뇨(Diabetes Mellitus)란 혈당을 조절하는 인슐린의 분비나 기능에 장애를 야기하는 질환으로 인슐린 의존성 여부에 따라 제 1 형과 제 2 형으로 분류된다. 본 종설은 최근 증가 추세에 있는 제 2 형 당뇨가 치수 치근단 병소의 병인 과정에 전구 위험요인으로 작용할 수 있는지를 평가 하고자 문헌고찰을 통해 당뇨의 병인 과정에서 특징적으로 나타나는 혈관 합병증에 관해 알아보고, 부가적으로 제 2 형 당뇨 쥐 모델에서 인위적인 치수 감염 후 얻은 치근단 조직의 조직병리학적 분석을 시행하였다. 조직학적 관찰 결과 제 2 형 당뇨 쥐에서 대조군에 비해 치수 치근단 병소의 크기가 증가하였고, 치수 염증 반응도 심하게 나타난 것으로 보아 당뇨 자체가 숙주를 감염에 취약한 상태로 만드는 전구 위험요소로 작용하였음을 알 수 있었다. 이러한 이유로는 첫째, 당뇨 시 전반적으로 나타나는 혈관 내 죽상 침착(atheromatous deposits)에 의해 혈관내벽의 두께가 두꺼워져 미세 순환의 장애는 물론 탐식 세포의 기능 저하, 면역 세포의 혈류 이동이 차단되어 치수 감염 시 쉽게 치근단 병소로 이환될 가능성이 높고, 둘째 치수 혈관에서 특징인 측부 순환(collateral circulation)의 부재에 따른 살균성 다형핵 백혈구의 활동 억제를 포함한 미세 혈관계의 취약성으로 인해 치수 조직의 재생능이 저하되어 추가적인 감염원의 공격에 대한 방어 및 치유 저하를 더욱 심화시키기 때문인 것으로 사료된다. 따라서 제 2 형 당뇨 환자의 수복치료 시 치과의사는 당뇨조절 하에서 치수 조직의 자극을 최소화하기 위한 세심한 처치가 필요하다. Diabetes Mellitus (DM) is a syndrome accompanied with the abnormal secretion or function of insulin, a hormone that plays a vital role in controlling the blood glucose level (BGL). Type land 2 DM are most common form and the prevalence of the latter is recently increasing, The aim of this article was to assess whet her Type 2 DM could act as a predisposing risk factor on the pulpo-periapical pathogenesis. Previous literature on the pathologic changes of blood vessels in DM was thoroughly reviewed. Furthermore, a histopathologic analysis of artificially-induced periapical specimens obtained from Type 2 diabetic and DM-resistant rats was compared. Histopathologic results demonstrate that the size of periapical bone destruction w as larger and the degree of pulpal inflammation was more severe in diabetic rats, indicating that Type 2 D M itself can be a predisposing risk factor that makes the host more susceptible to pulpal infection. The possible reasons may be that in diabetic state the lumen of pulpal blood vessels are thickened by atheromatous deposits, and microcirculation is hindered, The function of polymorphonuclear leukocyte is also impair ed and the migration of immune cells is blocked, leading to increased chance of pulpal infection. Also, lack of collateral circulation of pulpal blood vessels makes the pulp more susceptible to infection. These decrease the regeneration capacity of pulpal cells or tissues, delaying the healing process, Therefore, when restorative treatment is needed in Type 2 DM patients, dentists should minimize irritation to the pulpal tissue un der control of BGL