Histopathological profile of surgically removed persistent periapical radiolucent lesions of endodontic origin.

AIM: To determine the types of periapical lesions associated with root filled teeth with persistent periapical pathosis that required surgical treatment based on specific inclusion and exclusion criteria. METHODOLOGY: Periapical lesions from a consecutive clinical sample of 100 patients were examined histopathologically to determine a definitive diagnosis. RESULTS: Females were more represented (n = 56), the average age was 46.5 years and there were no age differences between gender or lesion type. A diagnosis of periapical granuloma was the most common finding with a similar number present in females (n = 40) and males (n = 37). A cyst was present in 18% of the cases with a majority of females (n = 12) represented in the sample. Evidence of foreign material, with an appearance consistent with endodontic sealer materials, was seen in 25 periapical granulomas, two cysts and one scar. Two periapical scars were seen, one had a history of apicectomy and amalgam root-end filling while the other was associated with extruded root filling material. CONCLUSIONS: By using defined clinical inclusion and exclusion criteria a predictable clinical diagnosis of a persistent periapical lesion due to endodontic origin can be reliably made. Periapical granulomas and cysts were the most common periapical lesions of endodontic origin associated with persistent periapical pathosis with the overall incidence of periapical cysts similar to previous studies. The presence of endodontic material in a high proportion of periapical lesions suggests a cause-effect association with the inference that clinicians should employ canal preparation techniques that limit apical extrusion of material.

Microscopic periradicular surgery: perioperative predictors for postoperative clinical outcomes and quality of life assessment.

The authors report on data from a self-assessment questionnaire filled out by 199 patients undergoing periradicular microscopic surgery at two private endodontic offices and at graduate endodontic clinics of the University of Pennsylvania. Regression analysis was performed using pain and swelling as dependent variables and age, sex, type of teeth, location, periapical lesion, and remedication as independent variables. Pain and swelling were significantly related to females and younger patients (p < 0.05). The results supported Etodolac as a pre- and postoperative analgesic and use of antibiotics restricted to high-risk patients. Maximum pain and swelling were reported at night and day 1 of the surgery, respectively. Generally, swelling was more often reported than pain. Surgeries in anterior maxilla were related to more pain and swelling. A majority of the patients (67%) rated surgical endodontics more pleasant than expected and found it less painful (46%) or the same (38%) as nonsurgical treatment. The results also point out that patients in general have negative beliefs and limited knowledge about periradicular surgery.

Periapical microsurgery: the effect of root dentinal defects on short- and long-term outcome.

INTRODUCTION: The purpose of this prospective clinical study was to evaluate the clinical outcome of endodontic microsurgery on roots exhibiting the presence or absence of dentinal defects at 1-year and 3-year follow-up period. METHODS: One hundred fifty-five teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a surgical operating microscope and a 0.8-mm head diameter light-emitting diode microscope diagnostic probe light. After inspection, root-end preparations were performed using ultrasonic tips, and root-end fillings were placed. Follow-up visits occurred at 1 year and 3 years postoperatively. The primary outcome measure used was the change in the radiographic apical bone density, and the secondary outcome measure used was the absence of clinical symptoms. RESULTS: Of the 155 treated teeth, a total of 134 teeth were assessed at the 1-year follow-up and 127 teeth at the 3-year evaluation. In the "intact" group, 94.8% healed at 1 year, and 97.3% healed at 3 years. In the "dentinal defect" group, 29.8% healed at 1 year, and 31.5% healed at 3 years. The baseline root condition of either "dentinal defect" or "intact" showed a statistical difference in the healing outcome at both 1 and 3 years. CONCLUSIONS: This prospective periapical microsurgery study showed a significant superior clinical outcome for intact roots when compared with roots with dentinal defects at both 1 year and at 3 years postoperatively.

A scanning electron microscopic study of in vivo ultrasonic root-end preparations.

The purpose of this in vivo study was to evaluate root-ends for cracks after root resection and again after ultrasonic root-end preparation in patients undergoing endodontic surgery. Endodontic surgery was performed on 25 roots from 20 patients. In vivo vinyl polysiloxane impressions were made after root resection and again after ultrasonic root-end preparations. Epoxy resin casts were made from the impressions and scanning electron micrographic examination of the root-end replicas was performed. There was no evidence of cracks after root resection. One incomplete canal crack was evident after ultrasonic root-end preparation.

Postsurgical endodontics.

Apical surgery is known to be an effective and practical way of treating endodontic failures. However, in spite of seemingly proper root end management, surgical failures may occur as a result of lateral canal, dentinal tubule, end retrograde leakage. Since surgical retreatment of such failures would likely result in failure, the alternative of a nonsurgical retreatment should be carefully considered. An understanding of the relationship which exists between the quality of the orthograde treatment and the surgical prognosis is necessary to properly direct the course of treatment.

Root deformation during root-end preparation.

Ultrasonic root-end preparation techniques have recently been introduced and revolutionized the field of endodontic surgery. However, several reports claimed that there was an increasing incidence of crack formation after ultrasonic root-end preparation. As yet, little work has focused on the root deformation during root-end preparation. Thus, the purpose of this investigation was to measure the amount of root deformation during root-end preparation with the use of microhandpiece and ultrasonic systems by using strain gauge methods, and simultaneously to detect any cracks with the aid of the stereomicroscope, stain, and an image processing system. The results demonstrated the ultrasonic instrumentation produced significantly greater strain on average than that generated with the microhandpiece system. From the viewpoint of fracture, any technique that could diminish the strain on the root would decrease the likelihood of fracture; however, no crack was observed on any resected surface of roots in this study.

Root-end fracture during retropreparation: a comparison between zirconium nitride-coated and stainless steel microsurgical ultrasonic instruments.

The purpose of this study was to evaluate a stainless steel (CT-5) and zirconium nitride coated (KiS) microsurgical ultrasonic instrument with regard to possible root-end fracture production during retropreparation. Forty extracted human central incisors were prepared in a crown-down fashion. Canals were obturated with gutta-percha by lateral condensation. Root-ends were resected. Teeth were placed in methylene blue for 48 h and evaluated by three independent evaluators under microscope. Teeth with existing fractures were eliminated from the study. The remaining teeth were randomly divided into two equal groups. Group A was prepared with the CT-5 tip and Group B with the KiS tip. Preparation time was recorded for all roots. The teeth were again immersed in methylene blue for 48 h and reevaluated. No root-end fractures were produced by either the KiS or CT-5 microsurgical ultrasonic instruments.

Effect of IRM root end fillings on healing after replantation.

The effect of IRM as a root end filling placed in teeth prior to replantation was examined in 21 molar teeth in monkeys. After extraction, root ends were resected, the canals contaminated with oral bacteria, root end cavities prepared, and fillings of IRM or amalgam placed prior to replantation. After 8 wk the jaws were removed and prepared for histological examination. Bacteria were demonstrated in only 9 of 15 teeth filled with IRM; 18 of the roots (60%) were associated with inflammation, which was only moderate or severe around 5 (17%), and extended > 0.1 mm around only 2 roots. In contrast, of the 6 teeth filled with amalgam, all contained bacteria in the root canals and 11 roots were associated with moderate or severe inflammation, which around 8 roots extended > 0.5 mm. The difference in severity of inflammation for the two materials was statistically significant (p < 0.001). The tissue response to root end fillings of IRM in replanted teeth was less severe and less extensive than that to amalgam.

The effect of irrigation with doxycycline or citric acid on leakage and osseous wound healing.

This study investigated the effect of doxycycline irrigation on wound healing and the apical seal of three filling materials. Part 1: 220 extracted teeth received root canal therapy followed by root resection (2 mm) and ultrasonic root end preparations (3 mm). Groups of 20 were irrigated with saline, citric acid, or doxycycline and filled with amalgam, Super EBA, or MTA. Leakage was measured (mm) after decalcification and clearing. Part 2: two defects were made on each side of the mandible of 10 New Zealand rabbits. On each side, one defect was irrigated with saline and one with either citric acid or doxycycline. The animals were killed in groups of five at 9 and 18 days. Sections of each defect were stained with hematoxylin and eosin for evaluation of healing and bone fill. Super EBA and MTA leaked significantly less than amalgam, regardless of irrigant. Leakage after irrigation with doxycycline compared to citric acid or saline was not significantly different for Super EBA or MTA but was lower for amalgam. There was no significant difference in healing or bone fill among irrigants at 9 or 18 days.

Efficacy of low level laser therapy in reducing postoperative pain after endodontic surgery-- a randomized double blind clinical study.

The aim of the study was to evaluate the effect of low level laser application on postoperative pain after endodontic surgery in a double blind, randomized clinical study. Fifty-two healthy adults undergoing endodontic surgery were included into the study. Subsequently to suturing, 26 patients had the operation site treated with an 809 nm-GaAlAs-laser (oralaser voxx, Oralia GmbH, Konstanz, Germany) at a power output of 50 mW and an irradiation time of 150 s. Laser treatment was simulated in further 26 patients. Patients were instructed to evaluate their postoperative pain on 7 days after surgery by means of a visual analogue scale (VAS). The results revealed that the pain level in the laser group was lower than in the placebo group throughout the 7 day follow-up period. The differences, however, were significant only on the first postoperative day (Mann-Whitney U-test, p<0.05). Low level laser therapy can be beneficial for the reduction of postoperative pain. Its clinical efficiency and applicability with regard to endodontic surgery, however require further investigation. This is in particular true for the optimal energy dosage and the number of laser treatments needed after surgery.

Relationship between apical and marginal healing in periradicular surgery.

OBJECTIVE: The purpose of the present study was to evaluate the relationship between apical and marginal periodontal healing after periapical surgery. STUDY DESIGN: The investigation was conducted on 59 patients referred for periradicular surgery. A radiographic examination as well as assessments of periodontal attachment and pocket depth of teeth undergoing surgery and control teeth were performed at the time of surgery and 1 year after surgery. The radiographic periapical healing pattern was evaluated. RESULTS: After an observation time of 1 year, 85% of the healing patterns were classified as successful or uncertain. Teeth within the surgical area showed a significant loss of clinical attachment during the observation period. The mean clinical attachment loss in teeth with an unsuccessful healing was 0.85 mm and differed significantly from successfully healed cases (mean, 0.15 mm). CONCLUSIONS: A persisting endodontic infection may be regarded as a contributing risk factor for a progressing marginal attachment loss.

A retrospective radiographic study of root-end surgery with amalgam and intermediate restorative material.

OBJECTIVE: We sought to compare amalgam with intermediate restorative material in terms of their effectiveness as root-end filling materials during root-end surgeries. STUDY DESIGN: A root-end operation was performed on 228 patients with 262 endodontically treated teeth with periapical lesions. Of these teeth, 122 from 101 patients were available for follow-up. Radiographs were taken immediately postoperatively and again at a mean of 11.25 months (range, 6-45 months) postoperatively. The radiographs were digitized, and the diameter of the periapical lesion was measured by means of a computerized system. The mesiodistal distance at the cementoenamel junction served as an internal standard. Radiographic findings were classified into 1 of 3 groups: complete healing, incomplete healing, or unsatisfactory (no) healing. RESULTS: Complete healing was observed in 44.3% of the teeth, incomplete healing in 21.3%, and unsatisfactory healing in 34.4%. No statistical significance was found for amalgam versus intermediate restorative material, but teeth that underwent additional operations had a significantly worse success rate than those that underwent only first-time operations. No correlation was found between the subjective prognosis by the surgeons and the long-term outcome. CONCLUSION: As root-end filling materials, amalgam and intermediate restorative material had the same clinical effectiveness. The classic root-end operation is unpredictable. Reoperations should be reconsidered and avoided if possible.

Leakage associated with intermediate restorative material and glass-ionomer cement retrograde fillings: a human and sheep teeth comparison with 2 different aging procedures.

OBJECTIVES: Leakage around retrograde fillings is an important cause of endodontic surgery. This in vitro study sought to compare the following: (1) methylene blue dye leakage linked to retrofillings in human and sheep teeth with the degree of dye penetration when intermediate restorative materials and Chemfil were used as retrofillings, (2) the apical microleakage in filled with that in unfilled root canals, and (3) 2 storage techniques, incubator-based and subcutaneous implantation in rats. STUDY DESIGN: Tested were 198 human and 196 sheep teeth that were retrofilled with intermediate restorative material or Chemfil, then stored in an incubator or subcutaneously in rats for 10, 20, and 30 days before immersion in methylene blue dye for 24 hours. Linear dye penetration was evaluated, and the results were statistically analyzed by means of analysis of variance. RESULTS: Leakage between sheep and human teeth was significantly different (P <.05). Chemfil had significantly less leakage than intermediate restorative material after storage in rat (P <.05) for up to 20 days, but not after 30 days. No differences were found between leakage of unfilled and filled human root canal teeth. CONCLUSIONS: The sheep incisor is a poor experimental model of the human tooth, and both aging procedures demonstrate extensive leakage of retrofilling materials after long-term storage.

Ultrasonic root end preparation.

Root end preparation techniques have historically been approached from the perspective of the restorative dentist. This article discusses how Black's principles for cavity design and preparation have been modified to reflect the advances in bonding chemistry.

Analysis of postoperative symptoms following surgical endodontic treatment.

OBJECTIVE: The purpose of this prospective study was to analyze postoperative pain and swelling of patients undergoing surgical endodontic treatment using a strict protocol incorporating measures to control postoperative symptoms. METHOD AND MATERIALS: The study consisted of 82 patients referred for surgical endodontic treatment. All surgical procedures were performed using a microsurgical technique employing strict protocol. All patients were premedicated with a single dose of oral dexamethasone (8 mg) preoperatively and two single doses (4 mg) 1 and 2 days postoperatively. Antibiotics were prescribed selectively only when severe symptoms were present due to infection. Patients were administered chlorhexidine mouthwash twice daily starting 3 days before the operation and an additional 7 days postoperatively starting the day after surgery. Cold compresses were applied on the skin at the site of surgery intermittently every 15 minutes during the operative day. Pain and swelling were recorded pre- and postoperatively, and the influence of different variables on postoperative sequelae were analyzed. RESULTS: One day postoperatively, 76.4% of the patients were completely pain free, less than 4% had moderate pain, and 64.7% did not report any swelling. The preoperative symptoms significantly influenced the pain experience post-surgery. CONCLUSION: There was a low incidence of postoperative pain and swelling following endodontic surgical treatment according to protocol with measures to control postoperative signs and symptoms. Patients with preoperative pain were more likely to have postoperative pain.

Management of diffuse tissue argyria subsequent to endodontic therapy: report of a case.

A case of severe mucogingival argyria secondary to leakage around and corrosion of silver cone root canal obturations and apical amalgam restorations is presented. Following removal of the silver points and re-treatment of the root canals, periradicular surgery was performed to remove the amalgam root-end restorations and reduce the amount of dispersed metallic particles in the subcutaneous tissues. Subsequent free gingival grafting created an esthetically pleasing and biologically acceptable result.

Incidence of pain after biomechanical preparation: a review of 302 cases treated by dental students.

Records of 302 root-filled teeth treated by dental undergraduates were reviewed by four lecturers in the Department of Conservative Dentistry, University of Malaya. Preoperative and operative factors were evaluated for their association with postoperative pain experience of patients during the visit immediately after completion of biomechanical preparation. Eighty four percent of patients did not experience any pain after biomechanical preparation whilst the remaining 16 percent only complained of slight or moderate pain. The incidence of pain after biomechanical preparation is not high even when performed by inexperienced undergraduates. Teeth with a pre-existing painful condition had a higher chances of postoperative of pain. The incidence of postoperative pain was halved when teeth were associated with a sinus tract.

[Optimization of structural characteristics of a root canal wall during retrograde tooth filling on a basis of scanning electron microscopy data]. / Optimizatsiia strukturnykh kharakteristik stenki kornevogo kanala pri retrogradnom plombirovanii po dannym ckaniruiushchei élektronnoi mikroskopii.

Studies by scanning electron microscopy showed that dentin of the root stump (resection of the root apex is an obligatory condition of retrograde filling) has numerous regular dentin tubules, in contrast to the apical part of the root. Mechanical treatment of dentin during preparation of the platform for retrograde filling leads to the formation of a thick "lubricating" layer on the surface of these platform. This layer consists of corpuscles of destroyed tissue substance (smudge) and completely covers the ends of dentin tubules, thus preventing the formation of strong bonds between the filling material and dentin surface. Treatment (pickling) of the platform surface with the conditioner notably improved the adhesion of Russian filling material Dentis to dentin. The best adhesive effect of retrograde filling was attained with Kemfil, the material requiring no pickling pretreatment.

Endodontic surgery failure: SEM analysis of root-end filling.

This study investigated the quality of root-end filling in cases of periapical lesions persisting after endodontic surgery. Ten patients requiring extraction of an endodontically treated tooth were included. The root-ends of extracted teeth were examined by scanning electron microscopy. Defects at the interface between the root-end filling and cavity margin were classified as ideal, imperfect (some marginal disruption) or inadequate (continuous marginal disruption involving >30% of the interface). Four cases were scored as imperfect, and six were scored as inadequate. A defective apical seal could favour continuous leakage of surviving bacteria and their by-products from the infected root canal system to periapical tissues, thereby sustaining inflammation.