Meetu R. Kohli

Outcome of endodontic surgery: a meta-analysis of the literature--part 1: Comparison of traditional root-end surgery and endodontic microsurgery.

INTRODUCTION The aim of this study was to investigate the outcome of root-end surgery. The specific outcome of traditional root-end surgery (TRS) versus endodontic microsurgery (EMS) and the probability of success for comparison of the 2 techniques were determined by means of meta-analysis and systematic review of the literature. METHODS An intensive search of the literature was conducted to identify longitudinal studies evaluating the outcome of root-end surgery. Three electronic databases (Medline, Embase, and PubMed) were searched to identify human studies from 1966 to October 2009 in 5 different languages (English, French, German, Italian, and Spanish). Relevant articles and review papers were searched for cross-references. Five pertinent journals (Journal of Endodontics, International Endodontic Journal, Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics, Journal of Oral and Maxillofacial Surgery, International Journal of Oral and Maxillofacial Surgery) were individually searched back to 1975. Three independent reviewers (S.S., M.K., and F.S.) assessed the abstracts of all articles that were found according to predefined inclusion and exclusion criteria. Relevant articles were acquired in full-text form, and raw data were extracted independently by each reviewer. Qualifying papers were assigned to group TRS or group EMS. Weighted pooled success rates and relative risk assessment between TRS and EMS were calculated. A comparison between the groups was made by using a random effects model. RESULTS Ninety-eight articles were identified and obtained for final analysis. In total, 21 studies qualified (12 for TRS [n = 925] and 9 for EMS [n = 699]) according to the inclusion and exclusion criteria. Weighted pooled success rates calculated from extracted raw data showed 59% positive outcome for TRS (95% confidence interval, 0.55-0.6308) and 94% for EMS (95% confidence interval, 0.8889-0.9816). This difference was statistically significant (P < .0005). The relative risk ratio showed that the probability of success for EMS was 1.58 times the probability of success for TRS. CONCLUSIONS The use of microsurgical techniques is superior in achieving predictably high success rates for root-end surgery when compared with traditional techniques.

Outcome of Endodontic Surgery: A Meta-analysis of the Literature—Part 2: Comparison of Endodontic Microsurgical Techniques with and without the Use of Higher Magnification

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 meta-analysis 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 1966 up to October 2009 in 5 different languages (ie, English, French, German, Italian, and Spanish). Review articles and relevant articles were searched for cross-references. In addition, 5 dental and medical journals (ie, Journal of Endodontics, International Endodontic Journal, Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics, Journal of Oral and Maxillofacial Surgery, and International Journal of Oral and Maxillofacial Surgery) 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.

Healing after root-end microsurgery by using mineral trioxide aggregate and a new calcium silicate-based bioceramic material as root-end filling materials in dogs

INTRODUCTION The purpose of this study was to compare healing after root-end surgery by using grey mineral trioxide aggregate (MTA) and EndoSequence Root Repair Material (RRM) as root-end filling material in an animal model. METHODS Apical periodontitis was induced in 55 mandibular premolars of 4 healthy beagle dogs. After 6 weeks, root-end surgeries were performed by using modern microsurgical techniques. Two different root-end filling materials were used, grey MTA and RRM. Six months after surgery, healing of the periapical area was assessed by periapical radiographs, cone-beam computed tomography (CBCT), micro computed tomography (CT), and histology. RESULTS Minimal or no inflammatory response was observed in the majority of periapical areas regardless of the material. The degree of inflammatory infiltration and cortical plate healing were not significantly different between the 2 materials. However, a significantly greater root-end surface area was covered by cementum-like, periodontal ligament-like tissue, and bone in RRM group than in MTA group. When evaluating with periapical radiographs, complete healing rate in RRM and MTA groups was 92.6% and 75%, respectively, and the difference was not statistically significant (P = .073). However, on CBCT and micro CT images, RRM group demonstrated significantly superior healing on the resected root-end surface and in the periapical area (P = .000 to .027). CONCLUSIONS Like MTA, RRM is a biocompatible material with good sealing ability. However, in this animal model RRM achieved a better tissue healing response adjacent to the resected root-end surface histologically. The superior healing tendency associated with RRM could be detected by CBCT and micro CT but not periapical radiography.

Biodentine Induces Human Dental Pulp Stem Cell Differentiation through Mitogen-activated Protein Kinase and Calcium-/Calmodulin-dependent Protein Kinase II Pathways

INTRODUCTION Biodentine (Septodont, Saint-Maur-des-Fossès, 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-κB), 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-κB (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 Biodentine-induced 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-κB 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.

A Survey of Cone-beam Computed Tomographic Use among Endodontic Practitioners in the United States

Introduction: Cone‐beam computed tomographic (CBCT) imaging is an emerging technology for clinical endodontic practice. The aim of this study was to investigate the acceptance, accessibility, and usage of CBCT imaging among American Association of Endodontists members in the United States by means of an online survey. Methods: An invitation to participate in a web‐based survey was sent to 3076 members of the American Association of Endodontists. The survey consisted of 8 questions on demographics, access to CBCT machines, field of view (FOV), frequency of use for particular applications, and reasons in case CBCT was not used. Results: A total of 1083 participants completed the survey, giving an overall completed response rate of 35.2%; 80.30% of the participants had access to a CBCT scan, of which 50.69% (n = 443) were on‐site and 49.31% (n = 431) were off‐site, and 19.30% of all respondents denied having access to CBCT imaging. Limited FOV was used by 55.26% participants, 22.37% used larger FOV formats, and the remaining 22.37% were not sure about the format. There was a significantly greater usage of CBCT technology in residency programs (n = 78/84 [92.86%]) compared with practitioners who had finished an endodontic specialty program (n = 796/999 [79.68%]) (χ2 = 10.30, P = .02). Practitioners used CBCT imaging “frequent” or “always” for internal or external resorptions (47.28%), preoperatively for surgical retreatment or intentional replantation (45.34%), missing canals (25.39%), preoperatively for nonsurgical retreatments (24.91%), differential diagnosis (21.16%), identifying periradicular lesions (18.26%), calcified cases (13.54%), immature teeth (4.71%), and to assess healing (3.87%). There was a significant difference in on‐site and off‐site CBCT imaging use for any of these applications (P < .001). Prevalent reasons for not using CBCT technology were cost (53.79%) and lack of installation space (8.29%). General concerns were expressed about resolution limitations, radiation exposure, and cost to the patient. Conclusions: There is a widespread application of CBCT technology in endodontic practice; however, results from the survey also confirmed that the benefit versus risk ratio should always be in favor of the patient if CBCT scans are taken.

A Comparison of 2- and 3-dimensional Healing Assessment after Endodontic Surgery Using Cone-beam Computed Tomographic Volumes or Periapical Radiographs

Introduction: The aim of this study was to compare the assessment of healing after endodontic microsurgery using 2‐dimensional (2D) periapical films versus 3‐dimensional (3D) cone‐beam computed tomographic (CBCT) imaging. Methods: The healing of 51 teeth from 44 patients was evaluated using Molvens criteria (2D) and modified PENN 3D criteria. The absolute area (2D) and volume (3D) changes of apical lesions preoperatively and at follow‐up were calculated by segmentation using OsiriX software (Pixmeo, Bernex, Switzerland) and ITK‐Snap (free software). Results: There was a significant difference between the mean preoperative lesion volumes of 95.34 mm3 (n = 51, standard deviation [SD] ±196.28 mm3) versus 6.48 mm3 (n = 51, SD ±17.70 mm3) at follow‐up (P < .05). The mean volume reduction was 83.7%. Preoperatively, mean lesion areas on periapical films were 13.55 mm2 (n = 51, SD ±18.80 mm2) and 1.83 mm2 (n = 51, SD ±.68 mm2) at follow‐up (P < .05). According to Molvens criteria, 40 teeth were classified as complete healing, 7 as incomplete healing, and 4 as uncertain healing. Based on the modified PENN 3D criteria, 33 teeth were classified as complete healing, 14 as limited healing, 1 as uncertain healing, and 3 as unsatisfactory healing. The variation in the distribution of the 2D and 3D healing classifications was significantly different (P < .05). Periapical healing statuses incomplete healing or uncertain healing according to Molvens criteria could be clearly classified using 3D criteria. Conclusions: CBCT analysis allowed a more precise evaluation of periapical lesions and healing of endodontic microsurgery than periapical films. Significant differences existed between the 2 methods. Over the observation period, the mean periapical lesion sizes significantly decreased in volume. Given the correct indications, the use of CBCT imaging may be a valuable tool for the evaluation of healing of endodontic surgery. HighlightsHealing after endodontic surgery was assessed by cone‐beam computed tomographic (CBCT) volumetric analysis (3‐dimensional [3D]) and periapical radiography (2‐dimensional [2D]).The healing classification in 3D (CBCT) analysis was significantly different from 2D (periapical radiography) analysis.The use of CBCT analysis may be a valuable tool for the evaluation of healing of endodontic surgery if indications are given.

Apicoectomy of maxillary anterior teeth through a piezoelectric bony-window osteotomy: two case reports introducing a new technique to preserve cortical bone

Two case reports describing a new technique of creating a repositionable piezoelectric bony window osteotomy during apicoectomy in order to preserve bone and act as an autologous graft for the surgical site are described. Endodontic microsurgery of anterior teeth with an intact cortical plate and large periapical lesion generally involves removal of a significant amount of healthy bone in order to enucleate the diseased tissue and manage root ends. In the reported cases, apicoectomy was performed on the lateral incisors of two patients. A piezoelectric device was used to create and elevate a bony window at the surgical site, instead of drilling and destroying bone while making an osteotomy with conventional burs. Routine microsurgical procedures - lesion enucleation, root-end resection, and filling - were carried out through this window preparation. The bony window was repositioned to the original site and the soft tissue sutured. The cases were re-evaluated clinically and radiographically after a period of 12 - 24 months. At follow-up, radiographic healing was observed. No additional grafting material was needed despite the extent of the lesions. The indication for this procedure is when teeth present with an intact or near-intact buccal cortical plate and a large apical lesion to preserve the bone and use it as an autologous graft.

Outcome of Endodontic Micro-resurgery: A Retrospective Study Based on Propensity Score–matched Survival Analysis

Introduction: The purpose of this retrospective study was to evaluate and compare the outcome of endodontic micro‐resurgery with that of primary endodontic microsurgery and determine prognostic factors affecting the outcome of micro‐resurgery. Methods: A clinical database was searched for endodontic microsurgery cases between 2001 and 2016. Nearest neighbor 2:1 propensity score matching for the following 5 variables was performed for cases of primary microsurgery and those of micro‐resurgery: age, sex, tooth type, lesion type, and postoperative restoration. For the matched cases, the outcome was categorized as success or failure according to clinical and radiographic evaluations performed at least 1 year after surgery. Kaplan‐Meier survival analysis and log‐rank tests were performed to compare the outcome of primary microsurgery with that of micro‐resurgery over time. For the micro‐resurgery group, multivariate Cox proportional hazard regression analysis was performed to identify prognostic factors and estimate their effects. Results: In total, 571 cases of endodontic microsurgery (498 primary microsurgery and 73 micro‐resurgery cases) were identified, and 146 cases of primary microsurgery were matched to 73 cases of micro‐resurgery through 2:1 propensity score matching. After matching, all covariates demonstrated an absolute standardized difference of <0.1. The estimated 5‐year success rates were 91.6% and 87.6% for primary microsurgery and micro‐resurgery, respectively (P = .594). The tooth type was found to be the only contributing factor for the outcome of micro‐resurgery, with molars showing a higher probability of failure than anterior teeth (hazard ratio, 8.53; P = .002). Conclusions: Within the limitations, the findings of this study suggest that the outcome of endodontic micro‐resurgery is comparable with that of primary endodontic microsurgery.

Outcome of Endodontic Surgery: A Meta-analysis of the Literature—Part 3: Comparison of Endodontic Microsurgical Techniques with 2 Different Root-end Filling Materials

Introduction: The aim of the present study was to investigate the influence of root‐end preparation and filling material on endodontic surgery outcome. A systematic review and meta‐analysis was conducted to determine the outcome of resin‐based endodontic surgery (RES, the use of high‐magnification preparation of a shallow and concave root‐end cavity and bonded resin‐based root‐end filling material) versus endodontic microsurgery (EMS, the use of high‐magnification ultrasonic root‐end preparation and root‐end filling with SuperEBA [Keystone Industries, Gibbstown, NJ], IRM [Dentsply Sirona, York, PA], mineral trioxide aggregate [MTA], or other calcium silicate cements). Methods: An exhaustive literature search was conducted to identify prognostic studies on the outcome of root‐end surgery. Human studies conducted from 1966 to the end of December 2016 in 5 different languages (ie, English, French, German, Italian, and Spanish) were searched in 4 electronic databases (ie, Medline, Embase, PubMed, and Cochrane Library). Relevant review articles on the subject were scrutinized for cross‐references. In addition, 5 dental and medical journals (Journal of Endodontics; International Endodontic Journal; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics; Journal of Oral and Maxillofacial Surgery; and International Journal of Oral and Maxillofacial Surgery) were hand checked dating back to 1975. All abstracts were screened by 3 independent reviewers (H.B., M.K., and F.S.). Strict inclusion‐exclusion criteria were defined to identify relevant articles. Raw data were extracted from the full‐text review of these selected articles independently by each of the 3 reviewers. In case of disagreement, an agreement was reached by discussion, and qualifying articles were assigned to group RES. For EMS, the same search strategy was performed for the time frame October 2009 to December 2016, whereas up to October 2009 the data were obtained from a previous systematic review with identical criteria and search strategy. Weighted pooled success rates and a relative risk assessment between RES and EMS were calculated. To make a comparison between groups, a random effects model was used. Results: Sixty‐eight articles were eligible for full‐text review. Of these, per strict inclusion exclusion criteria, 14 studies qualified, 3 for RES (n = 862) and 11 for EMS (n = 915). Weighted pooled success rates for RES were 82.20% (95% confidence interval [CI], 0.7965–0.8476) and 94.42% for EMS (95% CI, 0.9295–0.9590). This difference was statistically significant (P < .0005). Conclusions: The probability for success for EMS proved to be significantly greater than the probability for success for RES, providing best available evidence on the influence of cavity preparation with ultrasonic tips and/or SuperEBA (Keystone Industries, Gibbstown, NJ), IRM (Dentsply Sirona, York, PA), MTA, or silicate cements as root‐end filling material instead of a shallow cavity preparation and placement of a resin‐based material. Additional large‐scale randomized clinical trials are needed to assess other predictors of outcome. HIGHLIGHTSEndodontic microsurgery (EMS) with the use of high‐magnification ultrasonic root‐end preparation and root‐end filling with SuperEBA, IRM, MTA, or other calcium silicate cements has a high probability of success.Resin‐based endodontic surgery with the use of high‐magnification preparation of a shallow concave root‐end cavity with bonded resin‐based root‐end filling material performed less favorably than EMS.

Long-term Evaluation of Treatment Planning Decisions for Nonhealing Endodontic Cases by Different Groups of Practitioners

Introduction: The aim of this study was to investigate changes in treatment planning decisions among different practitioner groups over 7 years for teeth with apical periodontitis and a history of endodontic treatment. Methods: A Web‐based survey was sent to dentists in Pennsylvania in 2009 consisting of 14 cases with nonhealing periapical lesions and intact restorations without evidence of recurrent caries. Participants selected among 5 treatment options: wait and observe, nonsurgical retreatment (NSRTX), surgical retreatment (SRTX), extraction and fixed partial denture, or extraction and implant (EXIMP). In 2016, the identical survey was resent to the original 2009 participants. Results: In 2009, 262 dentists participated in the survey. Two hundred one participants were general practitioners (GPs: 76.7%), 26 endodontists (ENDOs: 9.9%), and 35 other specialists (prosthodontics, periodontics, and oral surgery [SPECs]: 13.4%) (n = 262). EXIMP, NSRTX, and SRTX were fairly equally selected but with great variation between practitioner groups (χ2 = 173.49, P < .05). A subset group of 104 participants (SUB) (39.7% of the original participants) retook the survey in 2016 (69 GPs [66.3%], 15 ENDOs [14.0%], and 20 SPECs [19.7%]). Comparisons among practitioner groups were significantly different in SUB (n = 104) for 2009 (χ2 = 95.536, P < .05) and 2016 (χ2 = 109.8889, P < .05). Intragroup reliability between 2009 and 2016 revealed no significant differences between the overall treatment planning choices for all practitioners (GPs, ENDOs, or SPECs). Intrapractitioner reliability showed many treatment planning decision changes on an individual level. Chances that individuals changed their original decision were 47.8% (95% confidence interval, 45.2%–50.4%) and were significantly different among the 3 practitioner groups (GPs > SPECs > ENDOs [χ2 = 11.2792, P < .05]). No significant changes were observed in the decision for tooth saving versus replacement treatment options (P = .520). Conclusions: No significant differences were noted between current and past treatment planning decisions in regard to tooth preservation by endodontic retreatment versus tooth extraction and replacement. However, individual practitioners lacked consistency in their decision making over time. Highlights:A 2‐time survey (in 2009 and 2016) was conducted to investigate treatment planning decisions for teeth with apical periodontitis and a history of endodontic treatment.Practitioners of different specialty groups chose between the options wait and observe, nonsurgical retreatment, surgical retreatment, extraction and fixed partial denture, and extraction and implant.Both in 2009 and 2016, great inconsistencies in regard to treatment planning existed among the different practitioner groups and also with regard to practitioner reliability when 104 participants repeated the identical survey in 2016.