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.

Pain and swelling after periapical surgery related to oral hygiene and smoking

OBJECTIVES

To evaluate pain and swelling during the first week after periapical surgery and its relation to patient age, gender, oral hygiene, and smoking.

STUDY DESIGN

One hundred two patients (31 men and 71 women) with a mean age of 40.2 years underwent periapical surgery. Age, gender, and oral hygiene and cigarette smoking before and during the postoperative course were noted. Pain and swelling scores were recorded on a descriptive 4-point scale at 2, 6, and 12 hours after surgery, and each day thereafter for 1 week. The data were statistically evaluated for significant differences.

RESULTS

The highest intensity of pain occurred during the first 48 hours, and swelling peaked on the second postoperative day. Patient age and gender had no significant effect on postoperative symptoms (P > .05). Patients with poor oral hygiene before surgery presented greater pain and swelling during the first postsurgical hours, and smokers before surgery also suffered more pain. The number of cigarettes smoked in the postoperative period and oral hygiene after surgery had no effect on pain or inflammation (P > .05).

CONCLUSIONS

Periapical surgery caused little pain and moderate swelling during the first 2 days after the intervention; these findings were more distinct in patients with poor oral hygiene before surgery and in smokers.

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.

Etodolac versus dexamethasone effect in reduction of postoperative symptoms following surgical endodontic treatment: a double-blind study

OBJECTIVE

The purpose of this prospective study was to analyze the effect of etodolac versus dexamethasone in reducing postoperative pain in patients who had surgical endodontic treatment using a strict protocol.

STUDY DESIGN

The study consisted of 90 patients (38 males and 52 females) referred for surgical endodontic treatment. All procedures were performed using a microsurgical technique with a strict protocol. Patients were randomly premedicated with placebo or with one of both protocols: either a single dose of oral dexamethasone, 8 mg, preoperatively and 2 single doses, 4 mg, 1 and 2 days postoperatively, or a single dose of etodolac, 600 mg, and 2 single doses, 600 mg, 1 and 2 days postoperatively. Pain was recorded at 8, 24, and 48 hours, as well as 7 days postoperatively, on a 1-10 scale. The influence of different variables on postoperative sequelae was analyzed.

RESULTS

On a 1-10 scale, the mean values of pain report recorded were 3.8 +/- 2.9 (8 hours postoperatively), 2.93 +/- 2.4 (24 hours), 2.31 +/- 2.2 (48 hours), and 1.4 +/- 0.9 (7 days postoperatively). One day postoperatively, 41.8% of the patients reported no or very mild pain (score 1 or 2), whereas after 7 days, 87.9% reported no or very mild pain (score 1 or 2). Both etodolac and dexamethasone had a significant effect of reducing postoperative pain in patients who had surgical endodontic procedure compared with placebo (P < or = .001).

CONCLUSION

Postoperative pain following endodontic surgical treatment is not uncommon. Etodolac as well as dexamethasone might serve as a pain relief measure for postoperative pain in these patients.

Postoperative pain after root-end resection and filling

OBJECTIVE

To evaluate the pain experience following root-end resection and filling with Mineral Trioxide Aggregate or Intermediate Restorative Material.

STUDY DESIGN

Referred adult patients recruited using strict entry criteria were randomly allocated to receive either material. A standardized surgical technique was employed. Postoperative instructions and a pain questionnaire were given to each patient to record the severity of their pain at 3 time intervals-3-5 hours, 24 hours, and 48 hours after surgery-on a standard visual analog scale (VAS). Patients were also asked to record consumption of any self-prescribed analgesics, the type, and dosage.

RESULTS

At 3-5 hours after surgery, regardless of the material used, 90% of all patients experienced some level of postoperative pain. Twenty-four hours after surgery 82% of patients experienced pain, as did 72% after 48 hours. Thirty-seven percent of patients did not take any analgesics at all. In order of popularity, the analgesics taken were ibuprofen, acetaminophen, and acetaminophen plus codeine phosphate. The VAS measurements were reduced over time in both treatment groups (P < .001). There was no statistically significant difference in the proportion of subjects taking analgesics in each treatment group. Patients who used analgesics showed higher median VAS measurements at all time periods (P < .05).

CONCLUSIONS

There was no significant difference in the pain experienced by both treatment groups. The postoperative pain was of a relatively short duration, at its maximum intensity early in the postoperative period but progressively decreased with time. Even if pain relief medication was needed, nonprescription analgesics were adequate and effective.

Longitudinal study on microleakage of three root-end filling materials by the fluid transport method and by capillary flow porometry

AIM

(i) To compare the root-end sealing ability of IRM Caps (IRM), Fuji IX Capsules (Fuji IX) and Pro Root MTA Tooth-Coloured Formula (MTA) in teeth obtained from cadavers. (ii) Further research on leakage study methodology by means of comparison of the fluid transport method (FTM) and capillary flow porometry (CFP).

METHODOLOGY

Root canal treatment was performed on 33 cadaver teeth in situ 2 weeks prior to root resection and ultrasonic retropreparation (S12/90 degrees D-tip on Suni-Max), after which the teeth were retrieved from the cadavers. Two teeth were kept as positive and negative controls. The other teeth were divided in three different groups at random, with each group receiving one of the retrofill materials. Retrofills were exposed to water 5 min after placement. The teeth were stored at 37 degrees C for 12 h after which the root filling was removed. Microleakage (L in microL day(-1)) was measured for 24 h under a pressure of 1.2 atm using FTM and recorded as L = 0, 0 < L < or = 10, L > 10. The measurements were repeated after 1 and 6 months. After 6 months, leakage was also assessed by CFP in order to measure through pores and their diameters. Results were analysed statistically using nonparametric Kruskal-Wallis and Mann-Whitney U-tests, and Spearman correlation coefficients between the results of both methods were calculated. The level of significance was set at 0.05.

RESULTS

(i) A statistically significant difference could be demonstrated between Fuji IX and IRM at 1 month with FTM. FTM revealed a significant difference between Fuji IX and the other materials at 6 months, whereas CFP did not. However, using both methods, Fuji IX showed the best result. (ii) When comparing both techniques, CFP demonstrated through pores in all teeth, whereas with FTM in only 14 of the 31 teeth could through pores be demonstrated. A positive correlation between both methods was demonstrated.

CONCLUSIONS

Under the conditions of this study (i) the conventionally setting glass-ionomer cement Fuji IX showed the best results when used as a root-end material and (ii) CFP appeared to be a useful method for leakage evaluation of through pores in endodontics.

The influence of root-end resection and root-end cavity preparation on microleakage of root filled teethin vitro

AIM

To investigate in vitro the influence of root-end resection and root-end cavity preparation on leakage of root filled teeth.

METHODOLOGY

The root canals of 48 roots, 16 mandibular premolars (G1), 16 mandibular incisors (G2) and 16 maxillary incisors (G3), 12 mm in length, were enlarged using a modified 'balanced force' technique and filled with gutta-percha and sealer using lateral compaction. After setting, leakage along the canal was measured using a fluid transport model. Root-end resection and root-end cavity preparation were then performed, leaving roots 10 mm in length with root fillings of 7 mm (groups R1, R2 and R3, respectively). Fluid transport was measured again along the remaining root fillings of all groups using the same experimental conditions. Results of leakage before and after root-end resection were analysed statistically using the Kruskal-Wallis and Wilcoxon tests.

RESULTS

A total of 31% of the roots leaked before and 54% after root-end preparation; the difference was significantly different (P < 0.001). No significant differences were found either among groups G1, G2, G3 (P = 0.565) or among groups R1, R2, R3 (P =0.2628). Significant differences, however, were shown between groups G1-R1 (P = 0.0053), G2-R2 (P =0.0089) and G3-R3 (P = 0.0461).

CONCLUSIONS

Root-end resection and root-end cavity preparation compromised the seal of 7 mm root fillings in all tooth groups. Increased leakage was recorded in the following order: mandibular incisors > mandibular premolars > maxillary incisors.

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.

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.

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.

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.

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.

[Optimization of structural characteristics of a root canal wall during retrograde tooth filling on a basis of scanning electron microscopy data]

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.

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.

The use of 3D computerized reconstruction for the study of coronal microleakage

AIM

The purpose of this study was to evaluate a new method for studying coronal microleakage associated with root-filled teeth.

METHODOLOGY

Twenty human mandibular posterior teeth were prepared chemomechanically with the stepback technique and then divided into two groups of 10 teeth each. The canals were filled using lateral condensation of gutta-percha points; Roth's 801 was used as a sealer for the first group, and Ketac-Endo for the second. After 48 h, the temporary fillings in the access cavities were removed, the roots coated with three layers of nail polish and then the teeth were exposed to artificial saliva for 40 days. Subsequently, the crowns of the teeth were placed into Indian ink for 4 days before the coating was removed and the teeth embedded in a two-phase polyester resin. Serial cross sections were taken from each specimen using a microtome, and each cross section photographed under a stereoscopic microscope. The photographs of the cross sections were digitized using an image scanner and the contours of the external surface of the teeth, the obturated root canals and the boundaries of dye penetration were followed. Finally, a three-dimensional surface representation was achieved using the triangulation method.

RESULTS

Although the sample size and the experimental methods were not designed to form valid groups, the results showed that all roots obturated with Ketac-Endo sealer had dye microleakage, whilst only three teeth of the Roth's 801 group had dye microleakage.

CONCLUSIONS

The 3D reconstruction of dye microleakage proved to be an interesting method and a useful tool for the evaluation of coronal microleakage when using different types of root canal sealers.

Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment

Endodontic retreatment decision-making must include an appraisal of the costs of the different strategies proposed. In addition to direct costs, postoperative discomfort may have other consequences in terms of time off work, unscheduled visits and suffering. To establish a foundation for the appraisal of such indirect and intangible costs the present study was set up in which patients' assessments of pain and swelling after surgical and nonsurgical retreatment procedures were recorded. Ninety-two patients with 95 root-filled incisors and canine teeth exhibiting apical periodontitis were included in the study. The mode of retreatment was randomly assigned. Each day during the first post-treatment week patients assessed their degree of swelling and pain on horizontal 100-mm visual analog scales (VAS). The scales ranged from "no swelling" to "very severe swelling" and "no pain" to "intolerable pain", respectively. Consumption of self-prescribed analgesics and time off work were also recorded. Significantly more patients reported discomfort after surgical retreatment than after nonsurgical procedures. High pain scores were most frequent on the operative day while swelling reached its maximum on the first postoperative day followed by progressive decrease both in frequency and magnitude. Postoperative symptoms associated with nonsurgical retreatment were less frequent but reached high VAS values in single cases. Analgesics were significantly more often consumed after periapical surgery. Patients reported absence from work mainly due to swelling and discoloration of the skin. This was found to occur only after surgical retreatment. Conclusively, surgical retreatment resulted in more discomfort and tended to bring about greater indirect costs than nonsurgical retreatment.

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.

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.

The control of haemorrhage at the operative site during periradicular surgery

CLINICAL TECHNIQUE: Effective apical sealing in endodontic surgery requires a dry root-end cavity to insert the filling material. A number of procedures for controlling haemorrhage have been described in the literature. An improvement of these techniques is proposed in this paper: by using a mixture of surgical wax and fibres of calcium alginate. This device, easy to place, sterile and non-toxic, permits placement of a root-end filling under more favourable conditions.

Response of periradicular tissues to growth factors introduced into the surgical site in the root-end filling material

AIM

The objective of this study was to evaluate the healing of the periradicular tissues when exogenous growth factors were delivered to the respected root-end. The healing response was compared with that when Diaket was used as a control.

METHODOLOGY

Non-surgical root canal treatment was performed on mandibular teeth in mongrel dogs. Surgical treatment followed and included root-end resection and root-end cavity preparation. Insulin-like growth factor in combination with platelet-derived growth factor, or fibroblast growth factor alone, were then placed in the root-end preparations on a polylactic acid carrier (Atrisorb) with or without the incorporation of the carrier tetracalcium phosphate. The healing was evaluated at 60 days with regard to presence of inflammatory response, bone regeneration, periodontal ligament formation and cementum formation.

RESULTS

Osseous regeneration in the excisional would and periodontal formation were significantly greater when Diaket was used as the root-end filling material. Likewise, cementum deposition occurred significantly more frequently in the Diaket group (P < 0.05). The polylactic carrier Atrisorb remained in the surgical sites for the duration of the study.

CONCLUSIONS

The use of specific growth factors, FGF and a combination of IGF/PDGF, delivered to the prepared root end in a collagen carrier did not initiate the desired periradicular tissue response of regeneration. Diaket, as used in this study, did stimulate a periradicular tissue response compatible with regeneration.

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.

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.

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.

Effect of retrograde cavity preparations on root apexes

Ultrasonic cavity preparations in endodontic surgery has become a popular procedure with several advantages noted: Smaller cavities, deeper and cleaner preparations, less removal of surrounding bone needed for instrumentation and less removal of root apex dentin. Concern has been raised that lines of infraction have appeared in some instances when the ultrasonic instruments have been used. We wished to examine the result of cavity preparations in root apexes using five different methods: high and slow speed handpieces, sonic instruments, and ultrasonic instruments at two power settings, medium and high levels, respectively. The results showed that all the methods produced some infractions; the high power ultrasonics produced the most infractions while the lowest numbers were associated with the slow speed handpiece and ultrasonic instruments at the medium power setting.

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.

Histological healing following surgical endodontics and its implications in case assessment: a case report

Following extraction of a symptomatic mandibular premolar which had been subjected to two periradicular surgical procedures, significant apical healing was identified histologically. The implications of these findings are discussed in relation to contemporary advocated treatment regimens, case assessment, and interpretation for success and failure.

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.

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.

Scanning electron microscopic study of the apical dentine surfaces lased with ND:YAG laser following apicectomy and retrofill

The purpose of this investigation was to study the effects of a Nd:YAG laser on the cut surface of teeth using scanning electron microscopy (SEM). Eighteen single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. The apical 3 mm of each tooth were resected with a diamond fissure bur, and the teeth were randomly divided into two groups of nine teeth each. The resected surface of each root in one group was lased twice. The duration of lasing and the number of pulses were recorded for each tooth. The teeth were air dried, mounted on stubs, sputter-coated with gold-palladium and examined under SEM. Application of the Nd:YAG laser caused melting of apical dentine surfaces. The melted material resembled the appearance of glazed interconnected droplets. Resolidification and recrystalization of the melted areas appeared to be incomplete and discontinuous. Some areas between the glazed regions appeared similar to those of non-lased apical dentine resected root surfaces.

Electrochemical corrosion in the failure of apical amalgam. Report of two cases

Apicoectomy with retrograde amalgam is an accepted procedure for treating teeth that cannot be treated by nonsurgical methods. Some of these fail to heal for no apparent reason. Evidence is presented that indicates that some of these failures are caused by corrosion of the apical amalgam. Two cases are described in which the sinus tract that was associated with the failing retrograde amalgam was resolved without further surgery. To bring about the resolution, a zinc-enriched amalgam was placed in the crown that through an intervening conductor, reduced the rate of corrosion at the apex.

Spontaneous expulsion of a retrograde filling. Report of a case

The placement of a retrograde filling is designed to seal the apex of a tooth when conventional procedures have either failed or cannot be performed. This case report describes the mechanical failure of this procedure, as well as the expulsion of the filling material from the oral cavity.