The use of guided tissue regeneration in endodontic Microsurgery: Setting a threshold

Aim

We aimed to compare the radiographic outcomes of conventional and regenerative approaches in endodontic microsurgery (EMS) and set a critical defect size for healing in conventional and regenerative therapies.

Methodology

The study evaluated 53 root canal-treated teeth (33 patients) with periapical lesions. Among them, 19 teeth (35.8 %) were treated with regenerative treatment, whereas 34 teeth (64.1 %) were managed with the conventional approach. Conventional and regenerative approaches were performed by endodontic and periodontic residents under consultants' supervision. Healing was evaluated after a minimum period of 6 months by comparing pre- and post-operative cone-beam computed tomography (CBCT) findings. The radiographic interpretation was conducted by a single examiner who was not participating in the surgeries and was blind on the type of treatment prior to CBCT evaluation. New healing criteria were proposed owing to the limitations on the present criteria in evaluating endodontic surgery after regenerative treatment. Critical measurements were calculated for each approach based on periapical lesion dimensions.

Results

The regenerative approach presented significantly better healing than conventional treatment (mean, 1.21 and 1.59, respectively; p = 0.047). Based on the critical-point calculations, the conventional approach was effective in lesions of up to 3 mm depth and height, whereas the regenerative approach resulted in better healing rates in lesions with 3-9 mm depth and 3-6 mm height.

Conclusions

Performing the regenerative approach in EMS resulted in better healing rates than those of the conventional approach. The conventional approach is recommended for small periapical lesions, whereas the first had better results in larger lesions.

Comparison of a Novel Static Computer-aided Surgical and Freehand Techniques for Osteotomy and Root-end Resection

INTRODUCTION

This study compared the accuracy and efficiency of a novel static computer-aided surgical technique using a 3-dimensional (3D)-printed surgical guide (3D-SG) with a fully guided drill protocol (3D-SG FG) to the freehand (FH) osteotomy and root-end resection (RER).

METHODS

Forty-six roots from 2 cadaver heads were divided into 2 groups: 3D-SG FG (n = 23) and FH (n = 23). Cone-beam computed tomographic scans were taken preoperatively and postoperatively. The endodontic microsurgery was planned in Blue Sky Bio software, and the 3D-SG was designed and 3D printed. The osteotomy and RER were conducted using a guided twist drill diameter of 2 mm and an ascending tapered drill with diameters of 2.8/3.2, 3.2/3.6, 3.8/4.2, and 4.2 mm with respective guided drill guides. Two-dimensional and three-dimensional virtual deviations and angular deflection were calculated. Linear osteotomy measures and root resection angle were obtained. The osteotomy and RER time and the number of mishaps were recorded.

RESULTS

Two-dimensional and three-dimensional accuracy deviations and angular deflection were lower in the 3D-SG FG protocol than in the FH technique (P < .05). The height, length, and depth of the osteotomy and root resection angle were less in the 3D-SG FG protocol than in the FH technique (P < .05). The osteotomy and RER time with the 3D-SG FG protocol were less than the FH method (P < .05).

CONCLUSIONS

Within the limitations of this cadaver-based study using denuded maxillary and mandibular jaws, 3D-SG FG protocol showed higher accuracy than FH osteotomy and RER. Moreover, the 3D-SG FG drill protocol significantly reduced the surgical time.

Microsurgical endodontic treatment of the upper molar teeth and their relationship with the maxillary sinus: a retrospective multicentric clinical study

PURPOSE

To assess the clinical and radiographic success rate of microsurgical endodontic treatment of upper molar teeth in relationship with the maxillary sinus, with 12 months follow-up.

METHODS

Patients treated with microsurgical endodontic treatment of upper molar teeth in the period between 2017 and 2019 were recruited from two dental clinics according to specific selection criteria. The outcomes were determined based on clinical and radiographic results taken three, six and 12 months post-operatively, compared with those taken immediately before and after surgery. Clinical and radiographic outcomes were recorded. The distance between the most apical part of the root and of the lesion to the maxillary sinus was measured on CBCT images before the surgery. Patient-related outcomes were recorded.

RESULTS

Out of 35 patients evaluated, 21 were selected according with the selection criteria for a total of 27 roots and 29 canals treated. After 12 months, 18 patients showed a complete healing whereas three demonstrated incomplete healing. Consequently, the success rate in this study was 85.7% after one year. In 28.5% (6 patients) there was a perforation of the Schneiderian membrane that didn't seem to affect the outcome. All patients kept the molar one year later. The pain level decreased significantly over the time during the first week after surgery.

CONCLUSION

Microsurgical Endodontic treatment of the upper molar teeth should be considered a valid and predictable treatment option even in case of Schneiderian membrane perforation. Future clinical studies with a larger sample size are needed to compare the results obtained.

Influence of incision on periodontal parameters after apical surgery: a meta-analysis

INTRODUCTION

The aim of the present meta-analysis was to determine the effect of the different incision designs used in apical surgery on periodontal parameters.

METHODS

An electronic search in Cochrane Library, Pubmed (MEDLINE), and Scopus was conducted on April 2020. Two independent investigators included clinical trials and prospective cohort studies comparing the influence of different incision designs used in apical surgery on gingival recession, periodontal probing depth, and clinical attachment level. A pairwise and network meta-analysis was performed in order to meta-analyze the direct and the indirect comparisons among the incision designs.

RESULTS

Six articles were included for the qualitative and the quantitative syntheses, involving a total of 401 teeth (372 patients). The pairwise meta-analysis did not reveal statistically significant differences between the incision designs in any of the outcomes evaluated. However, to reduce the amount of buccal gingival recession, the papilla base incision presented the highest probabilities of being ranked the most effective incision (85.7%), followed by submarginal incision (50.0%) and intrasulcular incision (14.3%).

CONCLUSION

Regardless of the incision design used, the periodontal parameters did not statistically differ after apical surgery.

CLINICAL RELEVANCE

Periodontal parameters did not significantly change despite the incision used in apical surgery. However, based on the results of the present review, the papilla base incision seems to be the best option to reduce the amount of buccal gingival recession.

Occurrence of Vertical Root Fractures after Apical Surgery: A Retrospective Analysis

INTRODUCTION

Vertical root fractures (VRFs) are among the most frequent causes of tooth loss, mainly of endodontically treated teeth. However, very few data is available about the occurrence of VRFs following apical surgery.

METHODS

Patient charts from 864 patients with 1058 teeth treated with apical surgery (September 1999 to December 2018) were retrospectively evaluated, if a VRF had occurred after surgery. The following, possibly influencing factors were analyzed: sex and age, type of treated tooth, primary versus resurgery, technique of root-end preparation, and timepoint of VRF diagnosis. Endpoints were either tooth extraction or the last follow-up.

RESULTS

The study cohort (55% women, 45% men) had a mean age of 52.00 ± 13.97 years (range 9-93 years). The overall rate of VRFs after apical surgery was 4% (42 of 1058 teeth). Among these 42 teeth, 33.3% were mandibular first molars and 26.2% were maxillary second premolars. The most frequently affected root was the mesial root of mandibular first molars (28.6%). With regard to the study parameters, significant differences of VRF rates were observed only for the type of tooth treated.

CONCLUSIONS

A low VRF rate of 4% was observed in this study. VRFs commonly occurred in maxillary premolars and mandibular molars, with the mesial root of mandibular first molars affected most frequently. This is in line with previous reports about VRFs in endodontically treated teeth without additional apical surgery.

Apical surgery in cancer patients receiving high-dose antiresorptive medication-a retrospective clinical study with a mean follow-up of 13 months

PURPOSE

The aim of the study is to evaluate the results of apical surgery (AS) in patients receiving high-dose antiresorptive medication (HDAR).

METHODS

Retrospective descriptive quality control study conducted in an Oral and Maxillofacial Department at a University Hospital. Fourteen patients on HDAR met the inclusion criteria. Only descriptive statistics were applied.

RESULTS

Fourteen patients had operation on seventeen teeth. Mean HDAR treatment period before apical surgery: 25 months (SD, ± 24.27; range, 1-78 months). Drug holiday during surgery and initial healing: mean, 8 months (SD, ± 5.96; range, 0.4-22 months). Sixteen out of seventeen teeth healed clinically and showed complete or ongoing radiographic healing. All patients except one became free of symptoms. Mean follow-up: 13 months (SD, ± 9.05; range, 2-31 months). Radiographic healing according to Molven and Rud: 7, complete; 6, uncertain; 1, unsatisfactory. Three patients died during follow-up and were considered drop-outs.

CONCLUSIONS

The present case series suggest that apical surgery is a valid treatment option for apical periodontitis in patients on HDAR, where orthograde endodontic retreatment is not possible. None of the patients developed medication-related osteonecrosis of the jaw. Further studies in larger study groups and with longer follow-up periods are needed. The regional scientific ethical committee provided a document exemption, registration date 20 November 2013, and the local data protection agency approved handling of the recorded data (No. 2012-41-0045), registration date 11 January 2012.

An analysis of 174 teeth after 1 year

The objective of this paper was the analysis of the 1-year outcome of teeth treated with apical surgery and a recently introduced bioceramic root repair material (BCRRM) for root-end filling. Patients were consecutively enrolled from 2015 to 2017. Apical surgery included the modern technique, i.e. the use of a surgical microscope, ultrasonic preparation of a root-end cavity, and retrofilling with BCRRM. The cohort comprised 150 patients with 174 treated teeth. Patients were recalled one year after surgery for a clinical and radiographic re-examination. Three experienced observers evaluated the periapical radiographs with regard to periapical healing utilizing the healing criteria established by Rud et al. (1972) and Molven et al. (1987). Based on the clinical findings and the radiographic assessment, healing was judged as successful, uncertain, or failed. Study parameters included gender, age, type of treated tooth, and type of BCRRM (regular vs. fast set putty). At the 1-year follow-up, 170 teeth could be reexamined (drop-out rate 2.3%). Healing outcome was categorized as successful in 94.1%, uncertain in 4.1%, and failed in 1.8%. No significant differences were observed when comparing the success rates among the different subcategories of study parameters. The lowest success rate was noted in mandibular premolars (86.7%) but without reaching statistical significance. In conclusion, BCRRM appears to be a biocompatible root-end filling material showing excellent 1-year results. The success rate was similar to recently reported success rates for BCRRM in apical surgery.

Evaluation of Hydroxyapatite Granules, CERAMENT™, and Platelet-rich Fibrin in the Management of Endodontic Apical Surgery

AIM

The present study compared hydroxyapatite granules, CERAMENT™, and platelet-rich fibrin (PRF) in the management of endodontic apical surgery cases.

MATERIALS AND METHODS

The present study was conducted on 126 patients requiring apical surgery of both genders. Patients were treated with hydroxyapatite granules, CERAMENT™, and PRF and were recalled regularly for assessment of pain, mobility, presence or absence of sinus, and healing site.

RESULTS

The mean days taken for the disappearance of pain in group I was 51.2 days, in group II was 52.3 days, and in group III was 44.7 days. The difference was significant (p < 0.05). There was a less number of draining sinuses in II and III groups. This was statistically significant (p < 0.05). Significantly less area remained after surgical intervention in groups II and III compared to group I recorded at follow-up period. The difference was significant (p < 0.05).

CONCLUSION

Authors found PRF superior in terms of reducing pain, mobility, and sinus and improving the healing site as compared to hydroxyapatite and CERAMENT™.

CLINICAL SIGNIFICANCE

Platelet-rich fibrin is considered more superior in terms of reducing pain, mobility, and sinus and improving the healing site, and it can be advised in clinical practice for endodontic management.

Effects of Dimensions of Root-End Fillings and Peripheral Root Dentine on the Healing Outcome of Apical Surgery

Objective:

The objective of this study was to assess dimensions of root-end fillings (REFs), as well as peripheral root dentine (PRD) and their effects on the healing outcome of apical surgery.

Methods:

Cone beam computed tomography (CBCT) scans were utilized to measure the REF length and width and the PRD thickness in 61 roots of 53 teeth 1 year after apical surgery. Measurements were taken in the mesio-distal as well as bucco-lingual directions. The REF alignment with respect to the root axis was also evaluated. In addition, the dimensions of REF and PRD were assessed for possible correlations with the healing outcome. Criteria for determining the healing outcome included clinical and radiographic parameters.

Results:

The mean REF length was 2.02±0.52 mm. No significant differences were observed with regard to tooth groups, but one-canal roots had a significantly longer mean REF than two-canal roots (P=0.006). The mean REF widths were 1.14±0.24 mm mesio-distally and 2.61±1.24 mm bucco-lingually. Roots with two canals presented a significantly wider REF (P<0.001) in the bucco-lingual dimension but had a significantly narrower REF in the mesio-distal direction (P<0.001) compared to roots with single canals. PRD measured on average 1.19±0.23 mm at the resection level and 1.44±0.27 mm at the coronal end of the REF. Almost all REFs were perfectly aligned with the longitudinal axis of the roots. With regard to healing outcomes, no correlations were found with REF and PRD values, respectively.

Conclusion:

The mean REF length was 2.02 mm. On average, a thickness >1 mm of peripheral root dentine was maintained. The REF or PRD dimensions had no statistical effect on the healing outcome.

Histologic Response of Human Pulp and Periapical Tissues to Tricalcium Silicate-based Materials: A Series of Successfully Treated Cases

Pulpal/periapical responses of human teeth that are treated successfully with tricalcium silicate-based materials are extremely difficult to obtain because of the typical unavailability of these teeth for histologic examination. The present case series reports histologic and histobacteriologic findings of 3 human teeth that had undergone pulpotomy, orthograde retreatment, and apicoectomy/root-end filling using tricalcium silicate-based endodontic materials. The teeth were extracted after 34 days, 7 weeks, and 20 months, respectively, because of unusual circumstances. The extracted teeth were processed, paraffin embedded, sectioned, stained with hematoxylin-eosin or the modified Brown and Brenn technique, and examined with light microscopy. The recurrent observation for the 3 cases presented was the absence of inflammatory or foreign body reactions of the host tissues in contact with tricalcium silicate-based materials after different observation periods despite the identification of bacteria in dentinal tubules close to the site of operation. Wound healing was rapid with repair/regeneration of lost tissues with cementum and new bone trabeculae. Although the level of evidence for a case series is low because of the anecdotal nature of the reported episodes, the histologic results reported in the present case series illustrate the highly biocompatible and bioactive nature of the tricalcium silicate-based materials used in treating these cases.

Success rate 1 year after apical surgery: a retrospective analysis

PURPOSE

The aim of the current study was the retrospective analysis of the outcomes of teeth treated with apical surgery after a 1-year follow-up period. Furthermore, potential factors associated with the success rate were investigated.

METHODS

All patients were treated at the Clinic of Cranio-Maxillofacial and Oral Surgery at the University of Zurich between 2010 and 2017. To be eligible for inclusion, all patients were required to have undergone apical surgery with a retrograde root-end filling, and a 1-year follow-up examination at the University of Zurich. Treatment success at the 1-year follow-up time-point was defined as an absence of clinical complaints and radiographically determined healing. Parameters that were analysed included tooth localisation, periapical index of the preoperative lesion, administration of antibiotics, smoker status, histopathology of the apical lesion, radiographically determined sufficiency of root canal treatment pain and clinical signs of inflammation at the initial examination.

RESULTS

A total of 81 teeth fulfilled all the inclusion criteria. At the 1-year follow-up, 91.4% of the teeth exhibited successful clinical and radiographic healing. The type of tooth was significantly associated with the success of the surgery (p = 0.006), but radiological severity of periapical inflammation, lesion histopathology, administration of antibiotics, smoker status, the quality of the root canal treatment, and preoperative pain and clinical signs of inflammation were not.

CONCLUSION

The results of the present study suggest that apical surgery with retrograde root-end filling is a reliable therapy for the preservation of teeth. Furthermore, there are limited factors that affect the treatment outcome.

Proximity of Vascular Bone Channel in the Lateral Sinus Wall to Root Apices of Maxillary First Molars: A Cone-beam Computed Tomographic Analysis

INTRODUCTION

Apical surgery is frequently indicated in maxillary first molars. Occasionally, a vascular anastomosis in the lateral maxillary sinus wall can be observed during surgery. The aim of this study was to examine the distance between the vascular bone channel (VBC) and the root apices of maxillary first molars using cone-beam computed tomographic imaging.

METHODS

Cone-beam computed tomographic images of 104 maxillary first molars were oriented in the coronal plane to evaluate the distance between the roots and the VBC. The measurements were only recorded in relation to the buccal roots. In addition, demographic parameters and further measurements such as the diameter of the VBC and the proximity to the periapical pathology were evaluated.

RESULTS

A total of 210 VBCs were assessed. The mean distance from the VBC to the apices of the buccal roots of the maxillary first molars was 6.18 mm ± 3.84 mm. The VBC was mostly located intrasinusally (74.3%) and only rarely superficially (0.5%). The diameter of the VBC was on average 0.88 ± 0.32 mm.

CONCLUSIONS

In this study, the VBC was usually found closer to the mesiobuccal than to the distobuccal root apex. During preparation of the access window, the existence of the VBC should be kept in mind because the mesiobuccal roots of maxillary first molars undergo apical surgery to the buccally positioned roots only.

The use of Enamel Matrix Derivative (Emd) for Treatment of Combined Apicomarginal Lesions in Apical Surgery: A Retrospective Analysis

Objective

The outcome of apical surgery using modern techniques is favourable. However, the presence of a combined apicomarginal defect may negatively affect the postsurgical healing. The objective of this retrospective analysis was to assess the healing of teeth with apicomarginal defects treated with apical surgery and enamel matrix derivative (EMD).

Methods

This retrospective study evaluated the application of EMD in apical surgery of 17 teeth with apicomarginal defects. Cases were followed for at least 1 year, and healing was classified based on established clinical and radiographic criteria.

Results

The patient sample included nine females and eight males with a mean age of 50±18.2 years. Maxillary incisors (six lateral and four central) were the most frequently treated teeth. The majority of apicomarginal defects was located on the facial aspect of the root (70.6%) and belonged to defect class I (76.5%). Follow-up periods ranged from 1 to 5 years. Healing was successful in 14 teeth (82.4%).

Conclusion

The application of EMD resulted in a similar outcome as in previously published clinical studies related to regenerative techniques for the treatment of apicomarginal defects in conjunction with apical surgery.

Distances of root apices to adjacent anatomical structures in the anterior maxilla: an analysis using cone beam computed tomography

OBJECTIVES

The aim was to assess the anatomical relationship of anterior maxillary teeth to the nasal floor in patients referred for apical surgery.

MATERIALS AND METHODS

Cone beam computed tomographic images (CBCT) of 83 patients were analysed retrospectively to quantify the distances between the root apices of maxillary anterior teeth (canine to canine) to the nasal floor or maxillary sinus (whichever was closer). Secondary outcome variables were the distances of the periapical lesion to the nasal floor, distances of the apices to the labial and palatal bone plates as well as to the neighbouring teeth.

RESULTS

A total of 93 teeth (39 central, 35 lateral incisors and 19 canines) were analysed. The mean shortest distances of the apices to the nasal floor (or maxillary sinus) were 8.54 mm for central incisors, 9.49 mm for lateral incisors and 5.39 mm for the canines. The canines exhibited a significantly shorter distance to the nasal floor/maxillary sinus. In the presence of an osteolysis, the distance to the nasal floor was significantly shorter compared to the teeth without lesions. The lateral and central incisors showed significant proximity to each other at the level of the future surgical resection (3 mm from the apex).

CONCLUSIONS

A close proximity between apices and adjacent anatomical structures such as nasal floor, maxillary sinus or adjacent roots could be shown in some cases.

CLINICAL RELEVANCE

CBCT could be a valuable adjunctive imaging tool prior to apical surgery in the anterior maxilla to assess the risk for and decrease the incidence of damage to neighbouring anatomical structures such as the nasal floor, maxillary sinus or adjacent roots.

Clinical and Radiographic Outcomes of Apical Surgery: A Clinical Study

Background

Endodontic treatment is usually indicated when teeth with periapical lesions are encountered. However, sometimes root canal treatment results in failure. In that case, one of the treatment choices is retreatment by an orthograde approach. Surgical endodontic therapy is also an alternative to preserve the tooth. Various techniques have been suggested in the literature which has more predictable results. The introduction of modern surgical techniques have enhanced the results of apical surgery procedures. Operating microscopes, magnifying loupes, microinstruments, ultrasonic tips, and biologically acceptable root-end filling materials (such as MTA and SuperEBA) have been introduced to this field with the modern technique, thus the success rates of modern apical surgery has increased significantly.

Objective

The aim of the present study was to evaluate the clinical and radiographic outcomes and periotest values of apical surgery treatment.

Methods

A total of 112 teeth were included. SuperEBA and MTA were used as root-filling materials. The recorded parameters were gender, age, location of the tooth, the presence/absence of a post, coronal restoration of the tooth, previous surgical/nonsurgical treatment of the tooth, the size of periapical lesions, histopathology of periapical lesions, smoking habits. Also the periotest values were recorded.

Results

The overall success rate was 88.4%. With regard to the evaluated variables, only one parameter (tooth type) was found statistically significant. Although the periotest values were decreased after 6 months compared to immediately postoperative measurements, the values were still significantly higher than preoperative measurements.

Conclusion

In this study, apical surgery performed with the modern instruments has significantly successful results with 88.4% success rate.

Endoscopic Evaluation of Cut Root Faces and Histologic Analysis of Removed Apices Following Root Resection: A Clinical Study

Objective:

To evaluate the resection plane after root-end resection during apical surgery using endoscopy.

Methods:

Following apicectomy of 69 roots, the cut root faces were inspected with a rigid endoscope for the presence of unfilled areas of the root canal space, gaps between the obturated root canal and dentinal wall, isthmi, ‘opaque’ dentine and cracks. Endoscopic pictures were captured and assessed using a 12-sectorn transparent grid for determination of location of the studied elements. Furthermore, the removed apices were examined histologically (n=47). The surfaces of the removed apices opposite the cut root faces were histologically analysed for the same outcome measures.

Results:

Endoscopy revealed the following findings: opaque dentine in 84.1%, unfilled parts of the root canal system in 59.4%, gaps between the existing root canal filling and dentinal walls in 49.3%, and cracks in 10.1% of cases. With regard to isthmi, histology of the removed apices demonstrated an isthmus in two-thirds of those seen with endoscopy at the root end. Ramifications were histologically observed only in 6 root apices.

Conclusion:

The studied elements may cause failure of the root canal treatment, and conventional root canal retreatment or apical surgery may be indicated. The clinical significance of opaque dentine with regard to tooth prognosis after apical surgery remains unclear and warrants further research.

Changes of Periodontal Parameters after Apical Surgery: Correlation of Clinical and Cone-beam Computed Tomographic Data

INTRODUCTION

The purpose of this study was to evaluate the changes of the marginal periodontium 1 year after apical surgery.

METHODS

Clinical and radiographic (cone-beam computed tomographic) examinations of 54 teeth treated with buccal access flaps for apical surgery were performed at baseline and after 1 year. Clinical assessment included measurements of probing pocket depth, the level of gingival margin (GM), and the width of keratinized tissue. Subsequently, the clinical attachment level (CAL) and the width of the attached gingiva were calculated. On bucco-oral cone-beam computed tomographic sections, the height and thickness of the crestal bone and the thickness of the alveolar bone were measured at different levels.

RESULTS

In general, the calculated mean changes of periodontal tissue and crestal/alveolar bone were only minimal. Significant mean changes included only GM and CAL on midoral aspects and the distance from the cementoenamel junction or restoration margin on midbuccal sites. CAL was further correlated with the thickness of the alveolar bone at 3 mm below the cementoenamel junction or restoration margin. None of the clinically and radiographically calculated mean changes were correlated with sex, biotype, or incision techniques. With regard to age, older patients showed significantly more gingival recession on the buccal aspect compared with younger individuals. Furthermore, mean changes of the midbuccal width of the attached gingiva were positively correlated with the healing outcome, whereas mean changes of the midoral GM and CAL were negatively correlated with the healing outcome.

CONCLUSIONS

Within an observation period of 1 year, the marginal periodontium and its underlying bone structures did not suffer from significant changes after apical surgery.

Modern Endodontic Microsurgery Concepts: A Clinical Update

Increased use of the surgical operating microscope in endodontic surgery has elucidated many shortcomings of previous techniques and along with microsurgical instruments and new more biologically acceptable root-end filling materials has started the new microsurgical era in surgical endodontics. Endodontic microsurgery is a minimally invasive technique that results in less postoperative pain and edema and faster wound healing. It offers a significantly higher success rate than traditional apical surgery technique. The components, key concepts and procedural steps of endodontic microsurgery as well as the prognosis and predictability of modern root-end procedures are presented in this review.

The resection angle in apical surgery: a CBCT assessment

OBJECTIVES

The primary objective of the present radiographic study was to analyse the resection angle in apical surgery and its correlation with treatment outcome, type of treated tooth, surgical depth and level of root-end filling.

MATERIALS AND METHODS

In the context of a prospective clinical study, cone beam computed tomography (CBCT) scans were taken before and 1 year after apical surgery to measure the angle of the resection plane relative to the longitudinal axis of the root. Further, the surgical depth (distance from the buccal cortex to the most lingual/palatal point of the resection plane) as well as the level of the root-end filling relative to the most coronal point of the cut root face was determined. Treated teeth were categorized into four groups (maxillary and mandibular anterior and posterior teeth). The final material comprised 62 treated roots in 55 teeth.

RESULTS

The mean calculated resection angle of all roots was 17.7° ± 11.4° (range -9.6° to 43.4°). Anterior maxillary roots presented the highest mean angle (25.8° ± 10.3°) that was significantly different from the mean angle in posterior maxillary roots (10.7° ± 9.4°; p < 0.001) and from the mean angle in posterior mandibular roots (15.1 ± 9.8°; p < 0.05). In roots with a shallow resection angle (≤20°), the rate of healed cases was higher than in roots with an acute resection angle (>20°), however without reaching statistical significance (p = 0.0905). Angles did not correlate either with the surgical depth or with the retrofilling length.

CONCLUSIONS

Statistically significant differences were observed comparing resection angles of different tooth groups. However, the angle had no significant effect on treatment outcome.

CLINICAL RELEVANCE

Contrary to common belief, the resection angle in maxillary anterior teeth was greater than in the other teeth. The surgeon is advised to pay attention to the resection angle when bevelling maxillary anterior teeth in apical surgery.

Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study

Objectives

The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery.

Materials and Methods

Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.0 mm on the cross-sectional view of CBCT.

Results

The second molar apex and apical 3 mm were located significantly deeper relative to the buccal bone surface compared with the first molar (p < 0.01). For the mandibular second molars, the distance from the buccal bone surface to the root apex was significantly shorter in patients over 70 years of age (p < 0.05). Furthermore, this distance was significantly shorter when the first molar was missing compared to nonmissing cases (p < 0.05). For the mandibular first molars, the distance to the distal root apex of one distal-rooted tooth was significantly greater than the distance to the disto-buccal root apex (p < 0.01). In mandibular second molar, the distance to the apex of C-shaped roots was significantly greater than the distance to the mesial root apex of non-C-shaped roots (p < 0.01).

Conclusions

For apical surgery in mandibular molars, the distance from the buccal bone surface to the apex and apical 3 mm is significantly affected by the location, patient age, an adjacent missing anterior tooth, and root configuration.

Changes of Root Length and Root-to-Crown Ratio after Apical Surgery: An Analysis by Using Cone-beam Computed Tomography

INTRODUCTION

Apical surgery is an important treatment option for teeth with post-treatment periodontitis. Although apical surgery involves root-end resection, no morphometric data are yet available about root-end resection and its impact on the root-to-crown ratio (RCR). The present study assessed the length of apicectomy and calculated the loss of root length and changes of RCR after apical surgery.

METHODS

In a prospective clinical study, cone-beam computed tomography scans were taken preoperatively and postoperatively. From these images, the crown and root lengths of 61 roots (54 teeth in 47 patients) were measured before and after apical surgery. Data were collected relative to the cementoenamel junction (CEJ) as well as to the crestal bone level (CBL). One observer took all measurements twice (to calculate the intraobserver variability), and the means were used for further analysis. The following parameters were assessed for all treated teeth as well as for specific tooth groups: length of root-end resection and percentage change of root length, preoperative and postoperative RCRs, and percentage change of RCR after apical surgery.

RESULTS

The mean length of root-end resection was 3.58 ± 1.43 mm (relative to the CBL). This amounted to a loss of 33.2% of clinical and 26% of anatomic root length. There was an overall significant difference between the tooth groups (P < .05). There was also a statistically significant difference comparing mandibular and maxillary teeth (P < .05), but not for incisors/canines versus premolars/molars (P = .125). The mean preoperative and postoperative RCRs (relative to CEJ) were 1.83 and 1.35, respectively (P < .001). With regard to the CBL reference, the mean preoperative and postoperative RCRs were 1.08 and 0.71 (CBL), respectively (P < .001). The calculated changes of RCR after apical surgery were 24.8% relative to CEJ and 33.3% relative to CBL (P < .001). Across the different tooth groups, the mean RCR was not significantly different (P = .244 for CEJ and 0.114 for CBL).

CONCLUSIONS

This CBCT-based study demonstrated that the RCR is significantly changed after root-end resection in apical surgery irrespective of the clinical (CBL) or anatomic (CEJ) reference levels. The lowest, and thus clinically most critical, postoperative RCR was observed in maxillary incisors. Future clinical studies need to show the impact of resection length and RCR changes on the outcome of apical surgery.

Sealing ability of root-end filling materials

BACKGROUND

The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators.

MATERIALS AND METHODS

Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance.

RESULTS

The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups.

CONCLUSIONS

All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.

Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study

Objectives

The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers.

Materials and Methods

The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test.

Results

There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation.

Conclusions

Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

Management of a large periapical lesion using Biodentine(™) as retrograde restoration with eighteen months evident follow up

Injury to anterior teeth is a common event. It requires a treatment approach that assures the complete biologic healing and functional restoration of the tooth or teeth involved. A cystic lesion, which is unable to heal nonsurgically, heals well with surgical intervention and use of mineral trioxide aggregate (MTA) as retrograde filling has been reported in literature. Another material with largely improved handling properties; Biodentine^™ (Septodont, St. Maurdes Fossés, France) was introduced in 2011. It is a calcium silicate based material and manufacturers claim that it can be used for crown and root dentin repair treatment, repair of perforations or resorptions, apexification, and root end fillings. This article presents a case report of surgical management of a large cystic lesion using Biodentine^™ as retrograde filling material which has not been reported in literature so far. Eighteen months radiographic follow-up exhibited completely healed cystic lesion.

The use of regenerative techniques in apical surgery: A literature review

Apical surgery has become a standard of care for tooth maintenance if conventional endodontic retreatment is not possible or associated with risks. However, in certain situations, the outcome of apical surgery may be compromised due to the extent or location of the periapical or periradicular lesions. The present review article including clinical and experimental studies reports and discusses the outcome of regenerative techniques (RT) in conjunction with apical surgery, with regard to the type of periradicular lesions:

APICAL LESIONS

The majority of studies have shown no benefit for healing in test sites treated with RT compared to control sites treated without RT. The use of a radio-opaque bone filler/substitute may even compound the radiographic interpretation of periapical healing. Currently, the use of RT for lesions <10 mm limited to the apical area is not warranted.

THROUGH-AND-THROUGH LESIONS

All reviewed studies demonstrated a better outcome for test sites with RT compared to the control sites without RT; hence the use of RT for treatment of tunnel lesions in apical surgery is recommended.

APICO-MARGINAL LESIONS

All clinical studies assessed cohorts without controls, and, therefore, no firm conclusion about the benefit of RT for treatment of apico-marginal lesions in conjunction with apical surgery can be drawn. However, the experimental animal studies have shown that healing of teeth with apico-marginal lesions appears to benefit from RT.

Apical surgery: A review of current techniques and outcome

Apical surgery is considered a standard oral surgical procedure. It is often a last resort to surgically maintain a tooth with a periapical lesion that cannot be managed with conventional endodontic (re-)treatment. The main goal of apical surgery is to prevent bacterial leakage from the root-canal system into the periradicular tissues by placing a tight root-end filling following root-end resection. Clinicians are advised to utilize a surgical microscope to perform apical surgery to benefit from magnification and illumination. In addition, the application of microsurgical techniques in apical surgery, i.e., gentle incision and flap elevation, production of a small osteotomy, and the use of sonic- or ultrasonic driven microtips, will result in less trauma to the patient and faster postsurgical healing. A major step in apical surgery is to identify possible leakage areas at the cut root face and subsequently to ensure adequate root-end filling. Only a tight and persistent apical obturation will allow periapical healing with good long-term prognosis. The present paper describes current indications, techniques and outcome of apical surgery.