The purpose of this study was to compare the periapical tissue responses and cementum regeneratio... more The purpose of this study was to compare the periapical tissue responses and cementum regeneration in response to three widely used root-end filling materials, amalgam, SuperEBA, and Mineral Trioxide Aggregate (MTA). These materials were placed using modern microsurgical techniques on endodontically treated dog premolars and molars. After 5 months, the cell and tissue reactions of surface-stained un-decalcified ground sections were evaluated by light microscopy and statistically analyzed. The major difference in the tissue responses to the three retrofilling materials were the degree of inflammation and types of inflammatory cells, number of fibrous capsule formations, cementum neoformation over these materials, osseous healing and resulting periodontal ligament thickness. MTA showed the most favorable periapical tissue response, with neoformation of cemental coverage over MTA. SuperEBA was superior to amalgam as a root-end filling material.
A previous report demonstrated 96.8% healing within 1 yr after apical surgery was performed with ... more A previous report demonstrated 96.8% healing within 1 yr after apical surgery was performed with the surgical operating microscope and Super-EBA as the root-end filling material. The purpose of this paper is to report on the long-term follow-up of those cases that were considered healed at the short term. Clinical examinations were made and radiographs were evaluated 5 to 7 yr after the case had first been considered healed. Criteria for determining healed cases were the same as those used in the first report. Of the 59 roots evaluated, 54 (91.5%) remained healed, whereas 5 (8.5%) showed evidence of apical deterioration.
This is the third of a five-part series (the second article) to appear in the Journal as part of ... more This is the third of a five-part series (the second article) to appear in the Journal as part of a Symposium on circulatory physiology of the pulp.
... In contrast to Kramer's study, which used human teeth and an India ink suction technique... more ... In contrast to Kramer's study, which used human teeth and an India ink suction technique, our study used dogs' teeth with a corrosive resin cast. Therefore, the difference in findings may be due to the different methods or specimens. ...
Pulpal hemodynamic regulation has been investigated in experimental animals using 133Xe washout, ... more Pulpal hemodynamic regulation has been investigated in experimental animals using 133Xe washout, 15-microns radioisotope-labeled microsphere injection, and intravital microscope methods. Three distinct types of pulp blood flow reductions were observed. Type I was characterized by reduction in response to direct stimulation of the sympathetic nerve; intraarterial infusion of norepinephrine, 5-HT, or prostaglandin F2 alpha; and indirect stimulation of the sympathetic nerve. The Type II response, an initial increase in flow followed by a decrease, was observed with isoproterenol, prostaglandin E2, substance P, and bradykinin. This biphasic flow response is caused by the low compliance environment of the tooth and may play a role in pulp inflammatory processes. The Type III response follows administration of histamine and is characterized by a gradual decrease in pulpal blood flow.
FIG 9. Six of the eight MR imaged levels of specimen 1, with corresponding drawings (D1 to D6) do... more FIG 9. Six of the eight MR imaged levels of specimen 1, with corresponding drawings (D1 to D6) done from two separate images that show pulpal and periodontal detail. MR images shown here were selected to show pulpal detail at the expense of the periodontal image. PM, periodontal
The incorporation of the microscope in clinical endodontics has had profound effects on the way e... more The incorporation of the microscope in clinical endodontics has had profound effects on the way endodontics is done and has changed the field fundamentally. This article outlines the key prerequisites for the use of the microscope in nonsurgical endodontic procedures, discusses which procedures benefit from using the microscope, and addresses the issue of cost versus patient benefit.
The ProFile instruments were among the first nickel-titanium (NiTi) instruments to be marketed. T... more The ProFile instruments were among the first nickel-titanium (NiTi) instruments to be marketed. This article describes the unique file design, clinical performance, safety concerns, and clinical applications of this system. Guidelines for NiTi rotary instrument usage need to be followed to minimize complications and maximize benefits.
Vasodilation, an important response in neurogenic inflammation, involves release of Substance P (... more Vasodilation, an important response in neurogenic inflammation, involves release of Substance P (SP) from the sensory nerve endings. It is now well known that SP causes edema formation and vascular relaxation in nondental tissues, however, the SP vasodilatory mechanism in the dental pulp is not completely understood. Endothelium-dependent relaxation is mediated by nitric oxide (NO) release with consecutive intracellular cyclic-GMP elevation in many vascular preparations. Recently, it has been shown in different vascular systems that SP-induced vasodilation is mediated by cyclic-GMP production through different pathways involving endothelial NO or direct endothelial-independent pathways. In the present study, the role of endothelial NO in SP induced vasodilation in the dental pulp was investigated to better understand the inflammatory mechanisms. Freshly extracted bovine dental pulp was used to measure NO production. Sodium nitroprusside (SNP), L-NAME and SP were utilized to induce and to inhibit NO production in endothelial cells. Released NO byproducts were measured with chemiluminescence assay technique. The present data demonstrate that SP induces NO production by activating NOsynthase (NOS) in endothelial cells. The NOS inhibitor L-NAME blocks NO production completely. In conclusion, in the bovine dental pulp, SP-induced vascular relaxation can be mediated by inducing NOS, and subsequently NO production in endothelial cells.
Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipm... more Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipment, instruments and materials that match biological concepts with clinical practice, we believe that microsurgical approaches produce predictable outcomes in the healing of lesions of endodontic origin. In this review we attempted to provide the most current concepts, techniques, instruments and materials with the aim of demonstrating how far we have come. Our ultimate goal is to assertively teach the future generation of graduate students and also train our colleagues to incorporate these techniques and concepts into everyday practice. (J Endod 2006;32: 601-623)
One of the major issues confronting the contemporary dental clinician is the treatment decision b... more One of the major issues confronting the contemporary dental clinician is the treatment decision between extracting a tooth with placement of a dental implant or preserving the natural tooth by root canal treatment. The factors that dictate the correct selection of one procedure over the other for each particular case are not yet established by randomized controlled studies. The aim of this review is to evaluate key factors allowing the clinician to make clinical decisions on the basis of the best evidence and in the patient's best interests. General considerations are discussed that will help the reader analyze clinical studies focused on this problem. Importantly, the major studies published to date indicate that there is no difference in long-term prognosis between single-tooth implants and restored root canaltreated teeth. Therefore, the decision to treat a tooth endodontically or to place a single-tooth implant should be based on other criteria such as prosthetic restorability of the tooth, quality of bone, esthetic demands, cost-benefit ratio, systematic factors, potential for adverse effects, and patient preferences. It can be concluded that endodontic treatment of teeth represents a feasible, practical, and economical way to preserve function in a vast array of cases and that dental implants serve as a good alternative in selected indications in which prognosis is poor. (J Endod 2008;34: 519 -529)
The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the he... more The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the healing success of cases having a lesion of endodontic origin compared with cases having a lesion of combined endodontic-periodontal origin. Data were collected from patients in the Department of Conservative Dentistry, Dental College, Yonsei University, Seoul, Korea between March 2001 and June 2005. A total number of 263 teeth from 227 patients requiring periradicular surgery were included in this study. Patients were recalled every 6 months for 2 years and every year thereafter to assess clinical and radiographic signs of healing. A recall rate of 73% (192 of 263 patients) was obtained. The successful outcome for isolated endodontic lesions was 95.2%. In endodontic-periodontal combined lesions, successful outcome was 77.5%, suggesting that lesion type (ABC vs DEF) had a strong effect on tissue and bone healing. (J Endod 2008;34:546 -551)
Introduction: The purpose of this study was to determine the bone regeneration potential to diffe... more Introduction: The purpose of this study was to determine the bone regeneration potential to different rootend filling materials by evaluating the distance between the materials and newly regenerated bone after root-end surgery. Material and Methods: Periapical lesions were induced in premolars and molars of five female beagle dogs. The teeth were treated endodontically after the development of the lesions. After 1 week, the teeth underwent root-end surgery using modern microsurgical techniques. Three different root-end filing materials were used: amalgam (Tytin; Kerr Mfg Co, Romulus, MI), SuperEBA (Bosworth, Skokie, IL), and mineral trioxide aggregates (MTA; Dentsply, York, PA). After 4 months, the dogs were sacrificed, and the jaws were prepared for histological sectioning. The distances from the root-end filling materials to the regenerated bone were determined by the evaluation of microradiographic images of the sections with imaging software (Sigma Scan/Image; Jandel Scientific Software, San Rafael, CA). The results were statistically analyzed with analysis of variance using Sigma Stat software (Jandel Scientific Software, San Rafael, CA). Results: The mean distances from the newly regenerated bone were 0.397 AE 0.278 mm in the MTA group, 0.756 AE 0.581 mm in the Super-EBA group, and 1.290 AE 0.386 mm in the amalgam group. There was a statistically significant difference between the amalgam and MTA groups (p < 0.05). No significant differences existed for amalgam versus SuperEBA and SuperEBA versus MTA. Conclusion: MTA showed the most favorable periapical tissue response. The distance from MTA to the regenerated bone was similar to the normal average periodontal ligament thickness in dogs. (J Endod 2010;36:1323-1325
Introduction: The extrusion of irrigation solutions beyond the apical constriction may result in ... more Introduction: The extrusion of irrigation solutions beyond the apical constriction may result in postoperative pain. Sodium hypochlorite can cause severe tissue irritation and necrosis outside the root canal system if extruded into the periodontal ligament (PDL) space. Different delivery techniques were discussed to reduce this potential risk. The aim of this study was to compare the postoperative level of pain after root canal therapy using either endodontic needle irrigation or a negative apical pressure device. Material and Methods: In a prospective randomized clinical trial, 110 asymptomatic single-rooted anterior and premolar teeth were treated endodontically with two different irrigation techniques. The teeth were randomly assigned to two groups. In the MP group (n = 55), procedures were performed using an endodontic irrigating syringe (Max-i-Probe; Dentsply Rinn, Elgin, IL). The EV group (n = 55) used an irrigation device based on negative apical pressure (EndoVac; Discus Dental, Culver City, CA). Postoperatively, the patients were prescribed ibuprofen 200 mg to take every 8 hours if required. Pain levels were assessed by an analog scale questionnaire after 4, 24, and 48 hours. The amount of ibuprofen taken was recorded at the same time intervals. Results: During the 0-to 4-, 4-to 24-, and 24-to 48-hour intervals after treatment, the pain experience with the negative apical pressure device was significantly lower than when using the needle irrigation (p < 0.0001 [4, 24, 48 hours]). Between 0 and 4 and 4 and 24 hours, the intake of analgesics was significantly lower in the group treated by the negative apical pressure device (p < 0.0001 [0-4 hours], p = 0.001 [4-24 hours]). The difference for the 24-to 48-hour period was not statistically different (p = 0.08). The Pearson correlation coefficient revealed a strongly positive and significant relationship for the MP group (r = 0.851, p < 0.001) and the EV group (r = 0.596, p < 0.0001) between pain intensity and the amount of analgesics. Conclusion: The outcome of this investigation indicates that the use of a negative apical pressure irrigation device can result in a significant reduction of postoperative pain levels in comparison to conventional needle irrigation. (J Endod 2010;36:1295-1301
Introduction: The aim of this study was to investigate the outcome of root-end surgery. It identi... more Introduction: The aim of this study was to investigate the outcome of root-end surgery. It identifies the effect of the surgical operating microscope or the endoscope on the prognosis of endodontic surgery. The specific outcomes of contemporary root-end surgery techniques with microinstruments but only loupes or no visualization aids (contemporary root-end surgery [CRS]) were compared with endodontic microsurgery using the same instruments and materials but with high-power magnification as provided by the surgical operating microscope or the endoscope (endodontic microsurgery [EMS]). The probabilities of success for a comparison of the 2 techniques were determined by means of a metaanalysis and systematic review of the literature. The influence of the tooth type on the outcome was investigated. Methods: A comprehensive literature search for longitudinal studies on the outcome of root-end surgery was conducted. Three electronic databases (ie, Medline, Embase, and PubMed) were searched to identify human studies from dating back to 1975 were hand searched. Following predefined inclusion and exclusion criteria, all articles were screened by 3 independent reviewers (S.B.S., M.R.K., and F.C.S.). Relevant articles were obtained in full-text form, and raw data were extracted independently by each reviewer. After agreement among the reviewers, articles that qualified were assigned to group CRS. Articles belonging to group EMS had already been obtained for part 1 of this meta-analysis. Weighted pooled success rates and a relative risk assessment between CRS and EMS overall as well as for molars, premolars, and anteriors were calculated. A random-effects model was used for a comparison between the groups. Results: One hundred one articles were identified and obtained for final analysis. In total, 14 studies qualified according to the inclusion and exclusion criteria, 2 being represented in both groups (7 for CRS [n = 610] and 9 for EMS [n = 699]). Weighted pooled success rates calculated from extracted raw data showed an 88% positive outcome for CRS (95% confidence interval, 0.8455-0.9164) and 94% for EMS (95% confidence interval, 0.8889-0.9816). This difference was statistically significant (P < .0005). Relative risk ratio analysis showed that the probability of success for EMS was 1.07 times the probability of success for CRS. Seven studies provided information on the individual tooth type (4 for CRS [n = 457] and 3 for EMS [n = 222]). The difference in probability of success between the groups was statistically significant for molars (n = 193, P = .011). No significant difference was found for the premolar or anterior group (premolar [n = 169], P = .404; anterior [n = 277], P = .715). Conclusions: The probability for success for EMS proved to be significantly greater than the probability for success for CRS, providing best available evidence on the influence of high-power magnification rendered by the dental operating microscope or the endoscope. Large-scale randomized clinical trials for statistically valid conclusions for current endodontic questions are needed to make informed decisions for clinical practice. (J Endod 2012;38:1-10)
Introduction: Biodentine (Septodont, Saint-Maur-des-Foss es, France), a new tricalcium silicate c... more Introduction: Biodentine (Septodont, Saint-Maur-des-Foss es, France), a new tricalcium silicate cement formulation, has been introduced as a bioactive dentine substitute to be used in direct contact with pulp tissue. The aim of this study was to investigate the response of human dental pulp stem cells (hDPSCs) to the material and whether mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-kB), and calcium-/ calmodulin-dependent protein kinase II (CaMKII) signal pathways played a regulatory role in Biodentine-induced odontoblast differentiation. Methods: hDPCs obtained from impacted third molars were incubated with Biodentine. Odontoblastic differentiation was evaluated by alkaline phosphatase activity, alizarin red staining, and quantitative real-time reverse-transcriptase polymerase chain reaction for the analysis of messenger RNA expression of the following differentiation gene markers: osteocalcin (OCN), dentin sialophosprotein (DSPP), dentin matrix protein 1 (DMP1), and bone sialoprotein (BSP). Cell cultures in the presence of Biodentine were exposed to specific inhibitors of MAPK (U0126, SB203580, and SP600125), NF-kB (pyrrolidine dithiocarbamate), and CaMKII (KN-93) pathways to evaluate the regulatory effect on the expression of these markers and mineralization assay. Results: Biodentine significantly increased alkaline phosphatase activity and mineralized nodule formation and the expression of OCN, DSPP, DMP1, and BSP. The MAPK inhibitor for extracellular signal-regulated kinase 1/2 (U0126) and Jun N-terminal kinase (SP600125) significantly decreased the Biodentineinduced mineralized differentiation of hDPSCs and OCN, DSPP, DMP1, and BSP messenger RNA expression, whereas p38 MAPK inhibitors (SB203580) had no effect. The CaMKII inhibitor KN-93 significantly attenuated and the NF-kB inhibitor pyrrolidine dithiocarbamate further enhanced the up-regulation of Biodentine-induced gene expression and mineralization. Conclusions: Biodentine is a bioactive and biocompatible material capable of inducing odontoblast differentiation of hDPSCs. Our results indicate that this induction is regulated via MAPK and CaMKII pathways. (J Endod 2014;40:937-942)
A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instr... more A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radiographically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.
The purpose of this study was to compare the periapical tissue responses and cementum regeneratio... more The purpose of this study was to compare the periapical tissue responses and cementum regeneration in response to three widely used root-end filling materials, amalgam, SuperEBA, and Mineral Trioxide Aggregate (MTA). These materials were placed using modern microsurgical techniques on endodontically treated dog premolars and molars. After 5 months, the cell and tissue reactions of surface-stained un-decalcified ground sections were evaluated by light microscopy and statistically analyzed. The major difference in the tissue responses to the three retrofilling materials were the degree of inflammation and types of inflammatory cells, number of fibrous capsule formations, cementum neoformation over these materials, osseous healing and resulting periodontal ligament thickness. MTA showed the most favorable periapical tissue response, with neoformation of cemental coverage over MTA. SuperEBA was superior to amalgam as a root-end filling material.
A previous report demonstrated 96.8% healing within 1 yr after apical surgery was performed with ... more A previous report demonstrated 96.8% healing within 1 yr after apical surgery was performed with the surgical operating microscope and Super-EBA as the root-end filling material. The purpose of this paper is to report on the long-term follow-up of those cases that were considered healed at the short term. Clinical examinations were made and radiographs were evaluated 5 to 7 yr after the case had first been considered healed. Criteria for determining healed cases were the same as those used in the first report. Of the 59 roots evaluated, 54 (91.5%) remained healed, whereas 5 (8.5%) showed evidence of apical deterioration.
This is the third of a five-part series (the second article) to appear in the Journal as part of ... more This is the third of a five-part series (the second article) to appear in the Journal as part of a Symposium on circulatory physiology of the pulp.
... In contrast to Kramer's study, which used human teeth and an India ink suction technique... more ... In contrast to Kramer's study, which used human teeth and an India ink suction technique, our study used dogs' teeth with a corrosive resin cast. Therefore, the difference in findings may be due to the different methods or specimens. ...
Pulpal hemodynamic regulation has been investigated in experimental animals using 133Xe washout, ... more Pulpal hemodynamic regulation has been investigated in experimental animals using 133Xe washout, 15-microns radioisotope-labeled microsphere injection, and intravital microscope methods. Three distinct types of pulp blood flow reductions were observed. Type I was characterized by reduction in response to direct stimulation of the sympathetic nerve; intraarterial infusion of norepinephrine, 5-HT, or prostaglandin F2 alpha; and indirect stimulation of the sympathetic nerve. The Type II response, an initial increase in flow followed by a decrease, was observed with isoproterenol, prostaglandin E2, substance P, and bradykinin. This biphasic flow response is caused by the low compliance environment of the tooth and may play a role in pulp inflammatory processes. The Type III response follows administration of histamine and is characterized by a gradual decrease in pulpal blood flow.
FIG 9. Six of the eight MR imaged levels of specimen 1, with corresponding drawings (D1 to D6) do... more FIG 9. Six of the eight MR imaged levels of specimen 1, with corresponding drawings (D1 to D6) done from two separate images that show pulpal and periodontal detail. MR images shown here were selected to show pulpal detail at the expense of the periodontal image. PM, periodontal
The incorporation of the microscope in clinical endodontics has had profound effects on the way e... more The incorporation of the microscope in clinical endodontics has had profound effects on the way endodontics is done and has changed the field fundamentally. This article outlines the key prerequisites for the use of the microscope in nonsurgical endodontic procedures, discusses which procedures benefit from using the microscope, and addresses the issue of cost versus patient benefit.
The ProFile instruments were among the first nickel-titanium (NiTi) instruments to be marketed. T... more The ProFile instruments were among the first nickel-titanium (NiTi) instruments to be marketed. This article describes the unique file design, clinical performance, safety concerns, and clinical applications of this system. Guidelines for NiTi rotary instrument usage need to be followed to minimize complications and maximize benefits.
Vasodilation, an important response in neurogenic inflammation, involves release of Substance P (... more Vasodilation, an important response in neurogenic inflammation, involves release of Substance P (SP) from the sensory nerve endings. It is now well known that SP causes edema formation and vascular relaxation in nondental tissues, however, the SP vasodilatory mechanism in the dental pulp is not completely understood. Endothelium-dependent relaxation is mediated by nitric oxide (NO) release with consecutive intracellular cyclic-GMP elevation in many vascular preparations. Recently, it has been shown in different vascular systems that SP-induced vasodilation is mediated by cyclic-GMP production through different pathways involving endothelial NO or direct endothelial-independent pathways. In the present study, the role of endothelial NO in SP induced vasodilation in the dental pulp was investigated to better understand the inflammatory mechanisms. Freshly extracted bovine dental pulp was used to measure NO production. Sodium nitroprusside (SNP), L-NAME and SP were utilized to induce and to inhibit NO production in endothelial cells. Released NO byproducts were measured with chemiluminescence assay technique. The present data demonstrate that SP induces NO production by activating NOsynthase (NOS) in endothelial cells. The NOS inhibitor L-NAME blocks NO production completely. In conclusion, in the bovine dental pulp, SP-induced vascular relaxation can be mediated by inducing NOS, and subsequently NO production in endothelial cells.
Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipm... more Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipment, instruments and materials that match biological concepts with clinical practice, we believe that microsurgical approaches produce predictable outcomes in the healing of lesions of endodontic origin. In this review we attempted to provide the most current concepts, techniques, instruments and materials with the aim of demonstrating how far we have come. Our ultimate goal is to assertively teach the future generation of graduate students and also train our colleagues to incorporate these techniques and concepts into everyday practice. (J Endod 2006;32: 601-623)
One of the major issues confronting the contemporary dental clinician is the treatment decision b... more One of the major issues confronting the contemporary dental clinician is the treatment decision between extracting a tooth with placement of a dental implant or preserving the natural tooth by root canal treatment. The factors that dictate the correct selection of one procedure over the other for each particular case are not yet established by randomized controlled studies. The aim of this review is to evaluate key factors allowing the clinician to make clinical decisions on the basis of the best evidence and in the patient's best interests. General considerations are discussed that will help the reader analyze clinical studies focused on this problem. Importantly, the major studies published to date indicate that there is no difference in long-term prognosis between single-tooth implants and restored root canaltreated teeth. Therefore, the decision to treat a tooth endodontically or to place a single-tooth implant should be based on other criteria such as prosthetic restorability of the tooth, quality of bone, esthetic demands, cost-benefit ratio, systematic factors, potential for adverse effects, and patient preferences. It can be concluded that endodontic treatment of teeth represents a feasible, practical, and economical way to preserve function in a vast array of cases and that dental implants serve as a good alternative in selected indications in which prognosis is poor. (J Endod 2008;34: 519 -529)
The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the he... more The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the healing success of cases having a lesion of endodontic origin compared with cases having a lesion of combined endodontic-periodontal origin. Data were collected from patients in the Department of Conservative Dentistry, Dental College, Yonsei University, Seoul, Korea between March 2001 and June 2005. A total number of 263 teeth from 227 patients requiring periradicular surgery were included in this study. Patients were recalled every 6 months for 2 years and every year thereafter to assess clinical and radiographic signs of healing. A recall rate of 73% (192 of 263 patients) was obtained. The successful outcome for isolated endodontic lesions was 95.2%. In endodontic-periodontal combined lesions, successful outcome was 77.5%, suggesting that lesion type (ABC vs DEF) had a strong effect on tissue and bone healing. (J Endod 2008;34:546 -551)
Introduction: The purpose of this study was to determine the bone regeneration potential to diffe... more Introduction: The purpose of this study was to determine the bone regeneration potential to different rootend filling materials by evaluating the distance between the materials and newly regenerated bone after root-end surgery. Material and Methods: Periapical lesions were induced in premolars and molars of five female beagle dogs. The teeth were treated endodontically after the development of the lesions. After 1 week, the teeth underwent root-end surgery using modern microsurgical techniques. Three different root-end filing materials were used: amalgam (Tytin; Kerr Mfg Co, Romulus, MI), SuperEBA (Bosworth, Skokie, IL), and mineral trioxide aggregates (MTA; Dentsply, York, PA). After 4 months, the dogs were sacrificed, and the jaws were prepared for histological sectioning. The distances from the root-end filling materials to the regenerated bone were determined by the evaluation of microradiographic images of the sections with imaging software (Sigma Scan/Image; Jandel Scientific Software, San Rafael, CA). The results were statistically analyzed with analysis of variance using Sigma Stat software (Jandel Scientific Software, San Rafael, CA). Results: The mean distances from the newly regenerated bone were 0.397 AE 0.278 mm in the MTA group, 0.756 AE 0.581 mm in the Super-EBA group, and 1.290 AE 0.386 mm in the amalgam group. There was a statistically significant difference between the amalgam and MTA groups (p < 0.05). No significant differences existed for amalgam versus SuperEBA and SuperEBA versus MTA. Conclusion: MTA showed the most favorable periapical tissue response. The distance from MTA to the regenerated bone was similar to the normal average periodontal ligament thickness in dogs. (J Endod 2010;36:1323-1325
Introduction: The extrusion of irrigation solutions beyond the apical constriction may result in ... more Introduction: The extrusion of irrigation solutions beyond the apical constriction may result in postoperative pain. Sodium hypochlorite can cause severe tissue irritation and necrosis outside the root canal system if extruded into the periodontal ligament (PDL) space. Different delivery techniques were discussed to reduce this potential risk. The aim of this study was to compare the postoperative level of pain after root canal therapy using either endodontic needle irrigation or a negative apical pressure device. Material and Methods: In a prospective randomized clinical trial, 110 asymptomatic single-rooted anterior and premolar teeth were treated endodontically with two different irrigation techniques. The teeth were randomly assigned to two groups. In the MP group (n = 55), procedures were performed using an endodontic irrigating syringe (Max-i-Probe; Dentsply Rinn, Elgin, IL). The EV group (n = 55) used an irrigation device based on negative apical pressure (EndoVac; Discus Dental, Culver City, CA). Postoperatively, the patients were prescribed ibuprofen 200 mg to take every 8 hours if required. Pain levels were assessed by an analog scale questionnaire after 4, 24, and 48 hours. The amount of ibuprofen taken was recorded at the same time intervals. Results: During the 0-to 4-, 4-to 24-, and 24-to 48-hour intervals after treatment, the pain experience with the negative apical pressure device was significantly lower than when using the needle irrigation (p < 0.0001 [4, 24, 48 hours]). Between 0 and 4 and 4 and 24 hours, the intake of analgesics was significantly lower in the group treated by the negative apical pressure device (p < 0.0001 [0-4 hours], p = 0.001 [4-24 hours]). The difference for the 24-to 48-hour period was not statistically different (p = 0.08). The Pearson correlation coefficient revealed a strongly positive and significant relationship for the MP group (r = 0.851, p < 0.001) and the EV group (r = 0.596, p < 0.0001) between pain intensity and the amount of analgesics. Conclusion: The outcome of this investigation indicates that the use of a negative apical pressure irrigation device can result in a significant reduction of postoperative pain levels in comparison to conventional needle irrigation. (J Endod 2010;36:1295-1301
Introduction: The aim of this study was to investigate the outcome of root-end surgery. It identi... more Introduction: The aim of this study was to investigate the outcome of root-end surgery. It identifies the effect of the surgical operating microscope or the endoscope on the prognosis of endodontic surgery. The specific outcomes of contemporary root-end surgery techniques with microinstruments but only loupes or no visualization aids (contemporary root-end surgery [CRS]) were compared with endodontic microsurgery using the same instruments and materials but with high-power magnification as provided by the surgical operating microscope or the endoscope (endodontic microsurgery [EMS]). The probabilities of success for a comparison of the 2 techniques were determined by means of a metaanalysis and systematic review of the literature. The influence of the tooth type on the outcome was investigated. Methods: A comprehensive literature search for longitudinal studies on the outcome of root-end surgery was conducted. Three electronic databases (ie, Medline, Embase, and PubMed) were searched to identify human studies from dating back to 1975 were hand searched. Following predefined inclusion and exclusion criteria, all articles were screened by 3 independent reviewers (S.B.S., M.R.K., and F.C.S.). Relevant articles were obtained in full-text form, and raw data were extracted independently by each reviewer. After agreement among the reviewers, articles that qualified were assigned to group CRS. Articles belonging to group EMS had already been obtained for part 1 of this meta-analysis. Weighted pooled success rates and a relative risk assessment between CRS and EMS overall as well as for molars, premolars, and anteriors were calculated. A random-effects model was used for a comparison between the groups. Results: One hundred one articles were identified and obtained for final analysis. In total, 14 studies qualified according to the inclusion and exclusion criteria, 2 being represented in both groups (7 for CRS [n = 610] and 9 for EMS [n = 699]). Weighted pooled success rates calculated from extracted raw data showed an 88% positive outcome for CRS (95% confidence interval, 0.8455-0.9164) and 94% for EMS (95% confidence interval, 0.8889-0.9816). This difference was statistically significant (P < .0005). Relative risk ratio analysis showed that the probability of success for EMS was 1.07 times the probability of success for CRS. Seven studies provided information on the individual tooth type (4 for CRS [n = 457] and 3 for EMS [n = 222]). The difference in probability of success between the groups was statistically significant for molars (n = 193, P = .011). No significant difference was found for the premolar or anterior group (premolar [n = 169], P = .404; anterior [n = 277], P = .715). Conclusions: The probability for success for EMS proved to be significantly greater than the probability for success for CRS, providing best available evidence on the influence of high-power magnification rendered by the dental operating microscope or the endoscope. Large-scale randomized clinical trials for statistically valid conclusions for current endodontic questions are needed to make informed decisions for clinical practice. (J Endod 2012;38:1-10)
Introduction: Biodentine (Septodont, Saint-Maur-des-Foss es, France), a new tricalcium silicate c... more Introduction: Biodentine (Septodont, Saint-Maur-des-Foss es, France), a new tricalcium silicate cement formulation, has been introduced as a bioactive dentine substitute to be used in direct contact with pulp tissue. The aim of this study was to investigate the response of human dental pulp stem cells (hDPSCs) to the material and whether mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-kB), and calcium-/ calmodulin-dependent protein kinase II (CaMKII) signal pathways played a regulatory role in Biodentine-induced odontoblast differentiation. Methods: hDPCs obtained from impacted third molars were incubated with Biodentine. Odontoblastic differentiation was evaluated by alkaline phosphatase activity, alizarin red staining, and quantitative real-time reverse-transcriptase polymerase chain reaction for the analysis of messenger RNA expression of the following differentiation gene markers: osteocalcin (OCN), dentin sialophosprotein (DSPP), dentin matrix protein 1 (DMP1), and bone sialoprotein (BSP). Cell cultures in the presence of Biodentine were exposed to specific inhibitors of MAPK (U0126, SB203580, and SP600125), NF-kB (pyrrolidine dithiocarbamate), and CaMKII (KN-93) pathways to evaluate the regulatory effect on the expression of these markers and mineralization assay. Results: Biodentine significantly increased alkaline phosphatase activity and mineralized nodule formation and the expression of OCN, DSPP, DMP1, and BSP. The MAPK inhibitor for extracellular signal-regulated kinase 1/2 (U0126) and Jun N-terminal kinase (SP600125) significantly decreased the Biodentineinduced mineralized differentiation of hDPSCs and OCN, DSPP, DMP1, and BSP messenger RNA expression, whereas p38 MAPK inhibitors (SB203580) had no effect. The CaMKII inhibitor KN-93 significantly attenuated and the NF-kB inhibitor pyrrolidine dithiocarbamate further enhanced the up-regulation of Biodentine-induced gene expression and mineralization. Conclusions: Biodentine is a bioactive and biocompatible material capable of inducing odontoblast differentiation of hDPSCs. Our results indicate that this induction is regulated via MAPK and CaMKII pathways. (J Endod 2014;40:937-942)
A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instr... more A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radiographically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.
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