Inter-appointment flare-up is an undesired event following infected root canal treatment both for the patient and for the clinician, and could undermine the clinician-patient relationship. A questionnaire survey on root canal treatment was conducted in February 2004, at University Hospital, Health Sciences University of Hokkaido, involving 171 dentists. The response rate of the survey was 64.3%. The average duration of clinical experience of the dentists who responded was 7.9 years. This report focuses on the topic of infected root canal treatment and subsequent inter-appointment flare-up regarding which six questions were asked. The majority had had cases of inter-appointment flare-up. The percentage of dentists who answered that inter-appointment flare-up frequently occurred was 71.4% in group A. The corresponding figures in groups B, C and D were 29.0, 13.6 and 13.8%. Frequencies of inter-appointment flare-up were reported to be 14.4, 8.0, 8.9 and 7.2% in groups A, B, C and D, respectively. Most of the clinicians answered that the mandibular first molar was the tooth with the highest occurrence of inter-appointment flare-up. Almost 50% of the clinicians answered that the cause of the flare-up was mechanical injury to the peri-radicular tissues. In conclusion, the results of the present study indicated that basic procedures of root canal treatment are of importance to prevent inter-appointment flare-up following infected root canal treatment.

View full abstract

The purpose of this study was to evaluate the effect of delayed application of the dropped all-in-one adhesives (Clearfil tri-S Bond and G-Bond) on enamel and dentin bond strengths. Human extracted premolars were used and flat enamel and dentin surfaces ground by 600-grit SiC paper were prepared. The tooth surfaces were treated with Clearfil tri-S Bond and G-Bond which were left for 0,5,10 and 30min after dropping of a adhesives on a shaded dish at constant temperature and humidity, and then covered with resin composites according to the manufacturers' instructions. After immersion in 37℃ water for 24 h, the teeth were serially sectioned into multiple slices and the micro-tensile bond strength was measured in a universal testing machine at a crosshead speed of 1.0mm/min. Data were statistically analyzed using one-way ANOVA and Dunnett's test at a significance level of 0.05. The weight changes of the dropped adhesives were also measured until 30 min under the shaded condition. In the comparison of the leaving time, a significant difference in the bond strength was only detected between 0 min and 30 min on enamel. The bond strength of Clearfil tri-S Bond to enamel after 30 min increased, but that of G-Bond after 30 min decreased (p<0.05). There was no significant difference in the bond strengths of Clearfil tri-S Bond and G-Bond to dentin. The weights of Clearfil tri-S Bond and G-Bond decreased with the leaving time after dropping and the percentage of the weights of adhesives were 82.7% for Clearfil tri-S Bond and 52.0% for G-Bond after 30min. These results suggested that the long-term leaving after dropping of the all-in-one adhesives affected the bond strengths to enamel bv evanoration of the solvents in adhesives.

View full abstract

The objective of the present study was to analyze patients referred to the Yokohama Dental and Medical Clinic at the Kanagawa Dental College (KDC) Yokohama Clinical Training Center for endodontic treatment. Subjects were patients with referrals from external dental clinics, hospitals, and other facilities for endodontic treatment at the KDC Yokohama Adult Dental Clinic between July 2002 and August 2005. Patient data such as diagnosis, treatment, and course were obtained from the information requested in the referral forms and the written medical records at the KDC Yokohama Clinic. The following results were obtained: 1. The tooth type with the most number of requests was the molar for both upper and lower jaws. 2. The most common diagnosis on the referral forms was periapical periodontitis. However, approximately 30% of the patients with a diagnosis of periapical periodontitis at the KDC Yokohama Clinic had received a different diagnosis at the referring facility. 3. In addition, among patients with a diagnosis of root fracture at the KDC Yokohama Clinic, 23% had been suspected of the same condition at the referring facility. 4. Among patients with a diagnosis of periapical periodontitis for whom follow-up was possible, approximately 78% had a "favorable" or "generally favorable" course after normal treatment of infected root canals and surgical endodontic treatment. Other patients required tooth extraction or were found to have teeth for which preservation was clearly impossible (approximately 18%) or which had an unfavorable course(approximately 4%). In addition, among patients treated only with normal treatment of infected root canals, approximately 85% had a "favorable" or "generally favorable" course. Possible reasons for the inability of referring facilities to manage these conditions include difficulty in identifying the causes due to undetected artificial perforations and root fractures, and inappropriate endodontic treatment. Considering that half of the patients at our clinic had undergone dental computed tomography or stereomicroscopy for diagnosis and treatment, the increase in the amount of visual data obtained from these devices was thought to be vital for fast diagnosis and efficient treatment. These findings indicate that adequate endodontic treatment based on appropriate diagnosis may lead to improvements in the determination of the feasibility of tooth restoration and the success rate of treatment.

View full abstract

Dental caries are caused by endogenous infection with bacteria resident in the oral cavity. The mutans streptococci are generally accepted as the main bacteria responsible for dental caries. Recently, many investigators have reported experimental studies of caries prevention using various antibacterial products. We focused on Diospyros Kaki Thunb. extracts, which have been used as crude drugs of plants since ancient times in Japan. The aim of this study was to determine the inhibitory effects of Diospyros Kaki Thunb. extracts as an anticariogenic component In vivo rat caries experiments were performed as follows JCL-Sprague-Dawley rats were infected orally with Streptococcus mutans PS-14. After sacrifice, the caries scores of the mandibles were determined by the Keyes method. Crude glucosyltransferase (GTase) was prepared from S. mutans PS-14 and activity was tested by measuring the total amounts of water-insoluble glucan (WIG). The following conclusions were obtained: 1. A significantly lower caries score was observed in specific pathogen-free rats infected with S.mutans PS-14 and fed with a cariogenic Diet 2000 containing 0.05% ursolic acid or 0.05% oleanolic acid as compared with controls fed the cariogenic Diet 2000 without Diospyros Kaki Thunb. extracts. 2. Diospyros Kaki Thunb. extracts showed an inhibitory effect on WIG formation from sucrose by crude GTase of S.mutans PS-14. In conclusion, the results of these in vivo rat experiments suggested that Diospyros Kaki Thunb. extracts have antibacterial activity against S.mutans.

View full abstract

We studied the effects of FGF-2 on the production of hyaluronan and heparan sulfate, glycosaminoglycan, by human dental pulp cells (HDPC). HDPC were isolated from healthy dental pulp of the first premolar teeth of individuals undergoing tooth extraction for orthodontic treatment and were cultured with α-MEM in the presence of 10% FCS. Alkaline phosphatase (ALPase) activity was determined by the method of Bessey et al. and calcified nodule formation was analyzed using Dahl's method. Production of hyaluronan and heparan sulfate was analyzed by competitive assay using hyaluronan-binding protein and ELISA assay, respectively. mRNA expression of extracellular matrix, hyaluronan synthetic enzyme and heparan sulfate synthesis-related enzymes was analyzed by a reverse transcription-polymerase chain reaction assay. HDPC expressed four kinds of FGF receptor mRNAs. FGF-2 reversely suppressed ALPase activity and formation of calcified nodules by HDPC, which were cultured with 10mmol/l β-glycerophosphate and 50μg/ml L-ascorbic acid. FGF-2 inhibited expression of collagen type I, DMP-1, and DSPP mRNA by HDPC and expression of collagen type I and PLAP-1 mRNA by human periodontal ligament cells (HPLC). FGF-2 did not alter the expression of collagen type III by either HDPC or HPLC. While HDPC did not change the production of heparan sulfate in response to FGF-2, HPLC increased its production. These cells did not change the expression of heparan sulfate synthesis-related enzymes mRNA. FGF-2 enhanced hyaluronan production by both HDPC and HPLC and HAS1 and HAS2 mRNA expression in both cells. This study revealed that FGF-2 modulates the production of proteoglycan by HDPC unlike human periodontal ligament cells.

View full abstract

Ceramics systems have become popular due to the demand for esthetic, durable restorative materials, and also due to improvements in materials, fabricating techniques, and bonding systems. However, there are deficiencies in their physical properties. The purpose of this study was to evaluate the effect of the coping system on ceramic by measuring the mechanical properties, adaptation of inlays and observation of the coping margins. The precious-metal coping material, Captek™ (Leach & Dillon, USA, Captek) was used for the experiment. Vintage Halo®(Shofu: Vintage Halo) and IPS Empress I® (Ivoclar-Vivadent: IPS Empress I) -fused-to-coping materials were prepared according to the manufacturers' instructions. The flexure strength was determined by using the Instron universal testing machine (cross head speed: 1mm/min, n=5). Fracture toughness (K_IC) was calculated by the Indentation microfracture technique using Niihara's formula (n= 5). These ceramics-fused-to-coping materials were observed by SEM. The cement thickness of IPS Empress I with and without coping at MOD inlays was also measured. The flexure strength (MPa) of the ceramics with coping showed significantly higher values (Vintage Halo 149.6±13.0, IPS Empress I 200.0±24.5) than the ceramics without coping (82.9±3.0, 151.4±5.7, p<0.05). In the fracture toughness (MNm^-3/2), IPS Empress I with coping showed significantly greater strengths (1.57±0.06) than those without coping (1.39±0.05, p<0.05). But Vintage Halo without coping showed significantly greater strengths (1.14±0.12) than those with coping (0.90±0.08, p<0.05). The interfaces of IPS Empress I and Vintage Halo-fused-to-coping materials showed no gaps. From the results of flexure strength, fracture toughness, and observation of the coping margin, the physical properties of IPS Empress I with coping definitely improved. Flexure strength of Vintage Halo definitely improved, and Vintage Halo and IPS Empress I showed good bonding interfaces between ceramics and Captek by SEM observation. But in the fracture toughness, Vintage Halo without coping showed significantly greater strengths than those with coping. This seems to be influenced by the mismatch of thermal expansion coefficient between Captek and Vintage Halo. Regarding cement thickness of IPS Empress I with coping and without coping, the width of the cement layer of ceramics with coping was generally wider than that of those without coping. This was caused by coping Captek transformation or exfoliation from refractory die material. Further consideration is necessary regarding the application of coping system on ceramic inlays.

View full abstract

This study examined the influence of storage and handling conditions of bonding agent on the enamel bond strength. Bonding systems used in this study included two kinds of one-step type (GB and AB), one kind of two-step(self-etching-primer+adhesive)type(MB), and one kind of three-step type (MP). Bovine enamel and flowable resin composite were used as the adhered materials. The bonding agents were stored at room temperature (23℃) or at refrigerated temperature (4℃). The bonding agents were removed from the refrigerator at 4℃ and allowed to reach 23℃ 8 hours before use (4℃⇔23℃). The storage period was 1, 30, 60, 90 and 180 days. In the case of the one-step type, an experiment was additionally performed in which the bonding procedure was made at 0, 1, and 2 minutes after dish sampling. The bonded specimens were subjected to a shear bond strength test after 24-hour immersion in distilled water. The results obtained were as follows: 1. For the GB and MB stored at 23℃, the bond strength decreased significantly when preserved for 90 and 180 days as compared with 1 and 30 days. 2. For the AB and MP stored at 23℃, the bond strength decreased significantly when preserved for 90 and 180 days as compared with 1, 30 and 60 days. 3. For the GB, MB and MP stored at 4℃ and 4℃⇔23℃, the bond strength decreased significantly when preserved for 180 days as compared with 1 day. 4. For the AB stored at 4℃ and 4℃⇔23℃, the bond strength decreased significantly when preserved for 90 and 180 days as compared with 1 day. 5. No significant difference was observed in the bond strength of the one-step type determined at 0, 1, and 2 minutes of the procedure after dish sampling irrespective of the storage conditions.

View full abstract

When taking a dental impression, it is necessary to decide the optimal time for removing the impression material. The removing time is important not only for accurate taking of the impression without any deformity, but also for minimizing the duration of the procedure. Until now, the decision about removing the impression material has been made on the basis of either the time recommended by the maker of the impression material, or material hardness determined by palpation by the operator. However, decisions made in such a way do not give optimal results, and therefore improved measurement methods and decision criteria are needed. In the present study, we evaluated the potential applicability of the Equotip hardness tester (Proceq, Switzerland), which is not only commonly used for measuring metallic and rock materials in industry, but also suitable for non-destructive and directiondefined measurement of small materials, by using the Equo effect. For this purpose, we prepared four commonly clinically used materials of three different types, and determined the correlation between their hardness that was measured after 60 minutes by the Equotip hardness tester and expressed as a L-value, and Young's modulus that was measured under the same experimental conditions. In addition, the hardness of impression materials was measured in real time by the tester, and the values compared with those measured by the recently used rheometer. The results obtained were as follows. 1) There was a significant correlation between Young's modulus and L-values, measured in the injection as well as putty type of dental elastomeric impression materials. 2) Correlation curves between the values measured by the rheometer and L-values could be obtained. 3) The load of the spring used in the rheometer markedly affected the final measured values. In contrast, the effect of the load of Equotip hardness tester on the final measured values was minimal. 4) It was concluded that the Equotip hardness tester is useful for the real time measurement of elastomeric properties of dental elastomeric impression materials. In addition, the measurement of L-values should be helpful for determining the optimal time for removing different dental elastomeric impression materials.

View full abstract

To evaluate a new device using burnable gas for the detection of oral malodor, 50 periodontitis patients and 20 healthy cohorts were enrolled, and the relationship between the oral malodor and progression of periodontitis was investigated. The following results were obtained: 1. Measured values of the burnable gas were 31.4±13.4 in the periodontitis group and 8.1±1.7 in the healthy cohorts. The periodontitis group showed significantly higher values than the healthy cohorts group, which suggests that a correlation exists between periodontitis and malodor. 2. In the periodontitis patients group, the measured value in pre-brushing was 30.8±16.6 and that in post-brushing was 26.5±13.3. The measured values reduced significantly after brushing, which suggests some association between plaque level and malodor. 3. There was no correlation between the measured values and the ratio of existing deep periodontal pockets greater than 4mm, which suggests that a factor affected the measured values other than the existing periodontal pockets. 4. The measurement of burnable gas was found to be an easy and effective method for the detection of mouth malodor.

View full abstract

One of the unexpected complications during root canal treatment is breakage of the instrument within the root canal. The commonly used techniques to removal a broken file from the root canal are the mechanical method, chemical method and surgical treatment. However, problems such as anatomical complexities and injury of the biological tissues are often encountered. There have been few reports on methods of removing nickel-titanium (NiTi) files. NiTi alloy is an excellent material with corrosion resistance owing to its oxide layer. It is known that the oxide layer is destroyed by halogen ions. This study investigated the corrosion of six types of NiTi files in a solution which reportedly corrodes NiTi alloy and is not a high density strong acid. Each file was made to rotate and break at a point 5mm from the tip. Solutions of 10% NaClO+19% NaCl (NCN) and 2 % NaF, made to a pH of 4.5 by adding phosphoric acid (APF) were used. The weight change was measured after a soaking test, the surface was observed by SEM and analyzed by a characteristic X-ray image, and quantitative analysis of Ni and Ti was performed using an electron beam microanalyzer. The results were as follows: 1. All files were corroded and dissolved within 24 hours by soaking in NCN and APF. 2. In NCN, corrosion progressed from the broken edge, a corrosion product was generated, and collapse due to dissolution resulting in rugged borders was observed in the SEM image. In APF, corrosion progressed over the whole surface, no corrosion products were generated, and dissolution by consecutive pitting corrosion was observed in the SEM image. 3. Observation of the X-ray images showed that in NCN, there was a selective decrease in parts of Ni whereas in APF, Ni and Ti decreased equally. 4. From the ratio of Ti and Ni determined by quantitative analysis, a relative decrease in Ni was observed in NCN. A decrease in both Ni and Ti was observed in APF. The results of this study suggested the possibility of removing a broken file by corrosion.

View full abstract

Adequate root canal irrigation that follows root canal preparation is one of the requisites for successful root canal treatment. Usually, root canal irrigation is performed by chemical or ultrasonic methods in the clinics. In this study, the characteristics of intracanal dentin surfaces irrigated with different conditions of the Er, Cr: YSGG laser system having controlled output frequency were examined by secondary electron image (SEI). The interface between dentin and root canal filling material was observed using SEI after obturation. Finally, dye penetration was performed to determine the sealing ability of root canal filling materials at the apex. The following conclusions were obtained as a result of these experiments. 1. Very smooth intracanal walls were observed by SEI, so the output frequency of the laser was high, and output level was low. Under all irrigation conditions, no smear layer was observed but opening dentinal tubule was observed. 2. Excellent attachment was observed between the intracanal surface and root canal materials in groups CL (Gutta-percha point+Canals-N: lateral condensation method) and WV(Obturation-gutta NT: Warm gutta-percha method)by SEI. Although the attachment was not inferior in group SS(Gutta-percha point+Super-Bond sealer: single cone technique), gaps existed between the canal wall and the root canal filling material. 3. There was no dye penetration at a point 1.5 mm from the apex. When using the Er, Cr: YSGG laser system for root canal irrigation, different conditions of laser irrigation may be required for root canal filling. Overall, it is suggested that the laser is suitable for clinical application.

View full abstract

The purpose of this study was to evaluate the effect of finishing agents on a tooth enamel surface that had been bleached using an office bleaching agent(containing 35% hydrogen peroxide)or a home bleaching agent (containing 10% carbamide peroxide). After being bleached in a clinical situation, bleached enamel is usually finished with a polishing agent containing fluoride. However, there have been few reports concerning the finish of tooth enamel after bleaching. With a view to reducing the occurrence of post-bleaching sensitivity and eliminating incidences of the color relapsing back to the original tooth shade, we treated the bleached tooth enamel surface using PMTC paste containing nano-hydroxyapatite particles and compared the effect of the paste with those of other finishing agents. Forty-eight recently extracted human anterior teeth were used. Nite White Excel™(10% carbamide peroxide, NWE), Shofu Hi-lite™(35%hydrogen peroxide, HL)and 35% hydrogen peroxide solution were used as bleaching agents. The bleaching method followed the manufacturer's instructions. The finishing agents used were Merssage (Shofu MER), MI-Paste(GC, MIP), and Renamel(Sangi, REN). We performed the following steps: we measured the particle size in each finishing agent; examined the enamel surface which had been surface treated by each finishing agent using SPM and determined the surface roughness(Ra); and performed a dye penetration test using coffee as the liquid. SPM observations of the enamel surface treated MER showed some roughness compared to the other groups. Those treated with MER also showed an increased average surface roughness(Ra). There was no change observed on the enamel surfaces treated with REN after the application of the bleaching agent. No pigmentation was observed on the enamel surfaces which were bleached with HL and then finished with REN. Dye penetration was obstructed on the specimens that were bleached with NWE and then finished with REN. It was thus concluded that REN effectively reduces the negative effects of a bleaching agent on an enamel surface, suggesting that nano-hydroxyapatite may have a surface restorative effect on tooth enamel in vitro.

View full abstract

At the last stage in infected root canal treatment, it is essential to know the appropriate timing for root canal filling. Traditionally, the existence of intracanal exudates, bad odor, and simple culture tests have been utilized. However, the low objectivity and long time of these methods have limited their use in clinical scenes. The purpose of this experiment was to evaluate the possibility of judging the timing for root canal filling, by measuring the paper points used for root canal medication by DIAGNOdent®, which is said to be useful in detecting caries. Different root canal medicaments (formcresol, formalin guaiacol, phenol camphor, Creodon®, Methocol®, chloramphenicol, and tincture of iodine), were soaked in paper points and measured by DIAGNOdent® at hourly intervals. Yellowish pus and transparent fluid collected in root canals during infected root canal treatment were measured in the same way. After these, the relations among clinical symptoms of a total of 57 cases, their DIAGNOdent® values (D values), and results of simple culture test at 24, 48, 72 hours were assessed statistically using Spearman's rank correlation coefficient (p<0.05). These showed that each medicament had a D value between 1 to 5, some of which changed a little as time passed, and that the D value of yellowish pus was higher than that of transparent fluid, both of which increased gradually as time passed. A significant statistical difference was noted between clinical symptoms and D values, but it was not noted between culture tests and D values. It is suggested that DIAGNOdent® measurement of paper points used in root canal medicament could be one of the indications in judging the appropriate time for root canal filling.

View full abstract

The purpose of this study was to evaluate the efficacy on caries dentin removal of caries detecting dye (Caries Check)in combination with DIAGNOdent® at dentin after Carisol™ treatment, compared with conventional methods. Twenty human extracted teeth with shallow caries on tooth crown and another twenty with deep caries were chosen and divided into two groups. After Carisolv™ treatment, existence of residual caries was detected by traditional ways: visual inspection with hardness checking or by Caries Check with DIAGNOdent®. After caries removal and conventional filling of prepared cavities with light-curing resin, samples were soaked in rhodamine B, and then bisected to be examined by stereoscopy and SEM. As a result, 20% of shallow caries and 50% of deep ones were dyed with Caries Check in the traditional inspection groups. Marginal leakage test and SEM examination showed traditional inspections had led to the formation of a gap between dentin and filled resin, and there was a significant difference in deep caries group, compared by Caries Check with DIAGNOdent®. It was suggested that to judge caries dentin removal using Carisolv™, the combination of Caries Check and DIAGNOdent® is required. Especially, at deep caries dentin removal, it is thought that this new judgment after Carisolv™ treatment is necessary.

View full abstract

Recently, requests to improve mild discoloration of teeth have been increasing, and bleaching treatment, which is less invasive while still achieving an esthetic improvement, has thus become increasingly popular. Current bleaching methods for vital teeth are classified broadly into two categories-namely, in-office bleaching in which dentists perform bleaching treatment at dental offices, and at-home bleaching in which patients perform such treatment at home. However, the effects of such bleaching treatments on healthy enamel have not yet been fully evaluated. Therefore, in order to elucidate the effects of vital tooth bleaching on the surface of the enamel, we observed the microstructure changes of the tooth surface by means of confocal laser scanning microscopy before and after bleaching using an in-office and an at-home bleaching agent (Hi Lite® and Nite White Excel®, respectively) in freshly extracted human teeth (young group from 20- to 30-year-old and elderly group from 60-year-old or older patients). Shade changes in the teeth were also scored. In addition, application of fluoride (Fluorident Gel; 9,000 ppmF) was also performed to improve the acid resistance of the enamel on the bleached surface, and calcium ion release from the tooth surface was measured. The following results were obtained: 1. The application of both Hi Lite and Nite White Excel to the tooth surface caused demineralization and an increase of surface roughness of the enamel. In addition, the surface roughness was improved by polishing the tooth surface. 2. The values of demineralization and surface roughness were higher in the young group than in the elderly group. 3. As for color change, both bleaching agents were effective, but in comparison to the elderly group, the shade score appeared to be more improved in the young group. 4. The topical application of fluoride to the bleached and polished tooth surface significantly decreased the calcium ion release from the enamel. No major microstructure changes of the enamel surface were found and no effects on tooth color were recognized. These findings indicated that not only polishing the tooth surface but also the application of fluoride, in an attempt to improve the acid resistance of the tooth structure, were together considered to be effective follow-up modalities after bleaching.

View full abstract

This study experimentally investigated the histopathological influence of the root canal open space following pulp removal in monkey teeth on the periapical and intracanal healing. Twenty fully developed maxillary and mandibular multirooted posterior teeth in a crab-eating monkey (Macaca irus) were used for this experiment. Pulp removal procedures were performed under general and local anesthesia, while using a rubber dam for all teeth. The root canal length was determined by using an electronic device (Endodontic Meter S, Onuki). After the canals of teeth were prepared on the apex, in most of them penetration a small-size reamer was done approximately 1.0mm beyond the apex. The canals were then irrigated alternately with 6% sodium hypochlorite (Purelox®) and 3% hydrogen peroxide, and sterile saline was used for washing. Sterile cotton pellets were placed in the canal orifices. All the cavities were carefully lined with zinc phosphate cement and then sealed with Clearfil Posterior® (Kuraray). The teeth were radiographed. Thirty-one months after the experiment, the animal was killed with intracardiac injections of 10% formalin. After decalcification by 20% formic acid, serial paraffin sections were cut at 8μm and stained with hematoxylin eosin and Gram stained for light microscope observation. The results were as follows: 1. In many teeth there were radiographically visible pathological changes. A widespread diffusely demarcated radiolucency was sometimes seen around the periradicular areas of mandibular molars 31 months later. In some cases of apical radiolucency, bone sclerosis appeared surrounding the entire periapical radiolucency. 2. In many teeth granulation tissue bridges had grown into or through the dead space of an unfilled root canal. 3. Most of the teeth developed root resorption which correlates with the presence of chronically inflamed granulation tissue. Maxillary third molars exhibiting slight root resorption showed the deposition of calcific repair tissue, called osteodentin, within the empty canal extending into the pulp chamber floor. 4. The top of the invaded granulation tissue in the apical canal became necrotic and there were infections in many teeth. Colonies of microorganisms with inflammatory cell infiltration of polymosphonuclear leukocytes in the necrotic tissue area were observed. 5. Pathological diagnosis of the radicular lesions was thought to be granuloma or chronic abscess in many cases.

View full abstract