Radiographic and histological evaluation of persistent periapical lesions associated with endodontic failures after apical microsurgery.

AIM: To determine the histology of persistent periapical lesions associated with nonsurgical endodontic treatment failures and to compare radiographically the sizes of periapical lesions and the presence or absence of the radiopaque lamina with the histological findings. METHODOLOGY: Ninety-three anterior teeth designated for apical microsurgery were included in the study. After taking standard radiographs of all cases using the parallel technique, the films were scanned and evaluated for the size of periapical radiolucent lesions and the presence or absence of radiopaque lamina by two calibrated observers. Biopsy specimens were obtained during apical microsurgery and examined under light microscopy by oral pathologists. Histological analysis established diagnoses of granuloma, cyst, abscess and scar tissue. Interobserver agreement was evaluated by the kappa test, and the relationship between histological diagnosis and lesion size was analysed by the Pearson's chi-square test. RESULTS: The 93 specimens consisted of 72% periradicular granulomas; 21.5% radicular cysts, including two keratocysts; 4.3% abscesses; and 2.2% scar tissue. Cystic prevalence increased as the size of the periapical lesion increased; however, there was no correlation between the presence of a radiopaque lamina and histological diagnosis of cyst. CONCLUSIONS: Neither radiographic size nor presence of an associated radiopaque line alone was sufficient to determine the type of lesion. Histological examination is required in order to reach to a definitive diagnosis.

Agreement between 2D and 3D radiographic outcome assessment one year after periapical surgery.

AIM: To compare 2D with 3D radiography in assessing the treatment outcome 1 year after periapical surgery. METHODOLOGY: In this prospective study, periapical radiographs (PA) and cone beam computed tomography (CBCT) were performed 1 year after periapical surgery. Three calibrated observers independently evaluated the radiographs for the presence and type of periapical radiolucencies. Ratings in PA were compared to those in bucco-lingual and mesio-distal CBCT images (coronal and sagittal planes), and the ratings of the latter two were also compared between each other. Further, maximum size diameters of radiolucencies were measured on CBCT scans, and the calculated means were correlated with the types of radiolucency. Statistical analysis was completed using Friedman rank sum tests, the Wilcoxon signed rank test and the Pearson correlation coefficient. RESULTS: A total of 61 roots in 54 patients were eligible for the final assessment. On average, the intra-observer ratings were identical in 59.6% when comparing PA and CBCT (kappa 0.112 to 0.192). A very high intra-observer agreement (93.4%) was noted when comparing bucco-lingual and mesio-distal CBCT ratings (kappa 0.797 to 1). Interobserver agreement was higher for PA (68.8%) than for CBCT (bucco-lingual 45.9%, mesio-distal 47.5%), but without reaching significant differences. The calculated mean size of persistent radiolucencies in CBCT scans correlated well with the assigned types of radiolucency. CONCLUSION: CBCT images showed in nearly a third of the evaluated cases a worse situation than PA. There is a need to define criteria to assess the 'radiographic healing' in CBCT following periapical surgery.

Accessory mental foramina and nerves: Application to periodontal, periapical, and implant surgery.

Recent studies investigating accessory mental foramina using developments in diagnostic imaging have primarily defined the morphology of the foramina; however, few studies have described the structures passing through them. Additional clinical knowledge of the foramina is therefore required for preoperative diagnosis prior to surgery, including implant, periodontal and periapical surgery. In this study, we investigated the accessory mental foramina and the associated nerves and arteries in donated cadaveric mandibles using anatomical and radiological observation methods. We examined 63 mandibles with overlying soft tissue by cone-beam computed tomography and noted the existence of the accessory mental foramina. Mandibles with accessory mental foramina were subsequently analyzed. Additionally, the neurovascular bundles passing through these foramina were dissected using anatomical methods.The incidence of accessory mental foramina was 14.3%. The larger foramina tended to be located anteriorly or superiorly and proximal to the mental foramen, while the smaller foramina tended to be located posterosuperiorly and distal to the mental foramen. The mental foramen ipsilateral to the accessory mental foramen was smaller than the one contralateral to it. The comparatively distant and large accessory mental foramen included an artery.This study elucidated the relationship between accessory mental foramina and the associated nerves and arteries. We believe that the results will contribute to the clinical dentistry field.

[Endodontic re-treatment or apical surgery, is an evidence-based choice possible?]. / Endodontische herbehandeling of apexresectie: is een evidencebased keuze mogelijk?

Treatment of a recurrence after an initial endodontic treatment can consist of endodontic re-treatment or apical surgery. The literature reports comparable success rates for these two options. However, randomised controlled trials that are truly comparable to each other are unavailable as a result of which comparison and an informed choice are not really possible. In addition to the treatment outcome, consideration also has to be given to cost-effectiveness and other patient-related factors, such as pain, swelling and medication. Regarding these considerations, too, little reliable information can be found in the literature. Moreover, factors relating to insurance play an important role in the Netherlands, where only apical surgery is covered by the basic healthcare insurance. In conclusion, all of these factors should be carefully considered before proceeding to an individual treatment strategy.

Effect of Recombinant Human Platelet-Derived Growth Factor on Healing of Chronic Periapical Tissue Pathosis Following Apical Surgery in a Canine Model: A Histomorphometric and Microcomputed Tomography Analysis.

This canine in vivo study assessed the effect of recombinant human platelet-derived growth factor (rhPDGF) on the healing of periapical tissues following apical surgery. From a total of 96 premolar teeth, 64 teeth from six beagle dogs (2 years old) were classified as experimental and were randomly assigned to four experimental groups (16 teeth per group). After having the pulp extirpated, leaving teeth open to the oral cavity for 1 week, and sealing with an immediate restorative material for 8 weeks, nonsurgical endodontic treatment was performed. A split-mouth design was used, and intra-animal randomization of treatment sides was applied to the groups as follows: apical curettage + 1.5-mm root-end resection (Group 1); apicoectomy + mineral trioxide aggregate (MTA) root-end filling (Group 2); apicoectomy + MTA root-end filling + rhPDGF (Group 3); and apical curettage + rhPDGF (Group 4). The animals were sacrificed 24 months after apical surgery, and histologic and µCT analyses were performed for bone volume loss (BVL). Group 1 showed partial resolution of the periapical lesions without signs of tissue regeneration (BVL: 49.09 ± 10.97 mm3). Group 2 had minimal bone regeneration and showed cementum reformation in 9 teeth, with no direct attachment to the MTA (BVL: 35.34 ± 10.97 mm3). Group 3 showed regeneration of all damaged apical tissues without direct contact between the cementum and MTA (BLV: 4.51 ± 1.55 mm3). Group 4 showed regeneration of PDL, bone, and cementum and attachment of functional cementum fibers (BVL: 2.82 ± 2.3 mm3). The difference in BVL was statistically significant only for Groups 1 and 2 (P < .05). rhPDGF may help regenerate apical tissue structures following apical surgery.

A prospective clinical study of polycarboxylate cement in periapical surgery.

OBJECTIVE: To evaluate the clinical efficacy of polycarboxylate cement as retrograde filling material. DESIGN: A prospective clinical study was made of 25 patients subjected to periapical surgery with ultrasound and magnifying loupes, in which polycarboxylate cement was used as retrograde filling material. Measurements were made of the area and diameter of the lesions pre- and postoperatively, and 6 and 12 months after the operation. The apical resection and retrograde filling areas were also measured, and the prognosis following surgery was recorded. RESULTS: A total of 23 patients with 31 apicoectomized teeth were studied (2 patients being lost to follow-up). The mean area of the periapical lesions before surgery was 52.25 mm2, with a mean major diameter of 6.1 mm and a mean lesser diameter of 4.8 mm. The success rate after 12 months was 54.7%, according to the criteria of Von Arx and Kurt. The prognosis was poorer in females, in larger lesions, and in cases with larger retrograde filling areas. CONCLUSIONS: Polycarboxylate cement offers good results, with important bone regeneration after periapical surgery.

Haemostatic effect and tissue reactions of methods and agents used for haemorrhage control in apical surgery.

AIM: To compare the haemostatic effect and tissue reactions of different agents and methods used for haemorrhage control in apical surgery. METHODOLOGY: Six standardized bone defects were prepared in the calvaria of six Burgundy rabbits. Five haemostatic modalities were tested for their haemostatic effect and tissue reactions, and were compared with untreated control defects: Expasyl + Stasis, Expasyl + Stasi + freshening of the bone defect with a bur, Spongostan, Spongostan+ epinephrine, and electro cauterization. The haemostatic effect was analysed visually and compared using Wilcoxon's signed rank test. Two groups of three animals were evaluated histologically for hard and soft tissue reactions related to the different haemostatic measures, after 3 and 12 weeks of healing respectively. RESULTS: Expasyl + Stasis and electro cauterization proved most effective in reducing bleeding (P < 0.05), but were accompanied by unfavourable tissue reactions, as indicated by the presence of necrotic bone, inflammatory cells and the absence of bone repair. These adverse tissue reactions did not recover substantially over time. However, adverse reactions were not observed when the superficial layer of bone had been removed with a rotary instrument. In contrast, Spongostan + epinephrine showed only a moderate haemostatic effect, but elicited also only mild adverse tissue reactions. CONCLUSIONS: Haemostasis in experimental bone defects is most effectively accomplished by using Expasyl + Stasis or electro cauterization. However, the bone defects should be freshened with a rotary instrument before suturing so as not to compromise healing.

Microscope versus endoscope in root-end management: a randomized controlled study.

The purpose of this prospective, randomized, clinical study was to monitor the outcome of periradicular surgery, in which either a surgical microscope or an endoscope was used as a magnification device. A total of 113 teeth in 70 patients were included in the study, according to specific selection criteria. The choice of endoscope or surgical microscope was made using a randomized table. One hundred cases were followed for at least 2 years. Of these, 59 root-end management procedures were performed using a microscope and 41 using an endoscope. At the 2-year follow-up they were classified into three groups (success, uncertain healing and failure) according to radiographic and clinical criteria. After a 2-year follow-up, 91 teeth (91%) healed successfully. In the group using an endoscope 90% of successful healing was achieved, while 92% of success was recorded for the group using a microscope. No statistically significant difference was found in the treatment results relating to the type of magnification device. The type of magnification device used did not seem to affect the outcome of endodontic surgery.

A comparative study of silver amalgam and compomer as retrograde filling materials in periapical surgery.

OBJECTIVE: A comparative study is made of the histological effects of silver amalgam versus compomer (Dyract) 90 days after placement as retrograde filling materials in experimental animals. METHOD: Six Beagle dogs were used, with total pulpectomy and orthograde material filling followed by periapical surgery of the 6 upper and 6 lower incisors (for a total of 72 teeth). Thirty-six teeth corresponded to the right side and were filled with the control material (silver amalgam), while the 36 teeth on the left side were filled with the compomer study material (Dyract). After three months the animals were sacrificed and the histological study was carried out, with evaluation of bone formation, inflammation, and the tissue in contact with the filler material. The results obtained were subjected to a descriptive and comparative statistical analysis (chi-square test). RESULTS: The samples retrogradely filled with compomer showed significantly greater percentage inflammation (76.19% versus 26.66% in the control group). On the other hand, a large proportion of samples with root cement growth were found in the compomer group. Filler material expulsion was also significantly more common when compomer was used. CONCLUSIONS: the comparative study of the histological findings showed greater inflammation but also greater root cement growth in the compomer group versus the controls.

Evaluation of healing criteria for success after periapical surgery.

INTRODUCTION: In periapical surgery, the absence of standardization between different studies makes it difficult to compare the outcomes. OBJECTIVE: To compare the healing classification of different authors and evaluate the prognostic criteria of periapical surgery at 12 months. MATERIAL AND METHODS: 278 patients (101 men and 177 women) with a mean age of 38.1 years (range 11 to 77) treated with periapical surgery using the ultrasound technique and a 2.6x magnifying glass, and silver amalgam as root-end filling material were included in the study. Evolution was analyzed using the clinical criteria of Mikkonen et al., 1983; radiographic criteria of Rud et al., 1972; the overall combined clinical and radiographic criteria of von Arx and Kurt, 1999; and the Friedman (2005) concept of functional tooth at 12 months of surgery. RESULTS: After 12 months, 87.2% clinical success was obtained according to the Mikkonen et al., 1983 criteria; 73.9% complete radiographic healing using Rud et al. criteria; 62.1% overall success, following the clinical and radiographic parameters of von Arx and Kurt, and 91.9% of teeth were functional. The von Arx and Kurt criteria was found to be the most reliable. CONCLUSION: Overall evolution according to von Arx and Kurt agreed most closely with the other scales.

Clinical Evaluation of Root End Resection Bevel in Periapical Surgery.

Root end resections play an important role in the success of periapical surgery. Beveling of the root end resections can vary significantly depending on the surgical technique, the root and canal morphology. The intention of this article was to clinically assess the root resections bevels and to estimate their relation to applied periapical surgeries. A prospective clinical study consisted of sixty periapical surgeries performed on teeth with chronic periapical lesions. Thirty periapical surgeries were performed in a conventional manner, while thirty were contemporary ultrasonic surgeries. Following the completion of strictly planned and performed intraoperative procedures, the resection bevels were assessed. To obtain the real bevel angles a compass was used. Root resections were significantly less beveled in all teeth operated with contemporary ultrasonic surgery, with mean values between 2.1° to 7.8°. The number of roots and their dilacerations didn't influence the root resection bevel. For comparison, root resections were significantly beveled in all conventionally operated teeth, with mean values of 46°. Due to the technical limitations of the conventional periapical surgery, mandibular premolars were exclusively operated with ultrasonic periapical surgery, with mean values of resection bevel not exceeding 20.7°. Significantly lesser resection bevel associated with ultrasonic periapical surgery contributes to root preservation and favorable surgical outcome.

Development of a new micro-endoscope for odontological application.

PURPOSE: Development and introduction of a new micro-endoscope called Visio Scope for multidiscipline use in dentistry. METHODS: During the development of the new micro-endoscope called Visio Scope testings in the following dental disciplines were performed: endodontics, periodontology, implantology, periapical surgery, prosthodontics, and laser treatment. In this first report, flexible micro-endoscopes with an external diameter of 1.0 mm as well as of 0.34 mm were used. RESULTS: There is a significant improvement in all tested disciplines concerning handling and flexibility, verification of radiologically not detectable findings. In this context, the endoscope has proved itself clearly superior to conventional optical aids, above all the surgical microscope. The working canal facilitates specific application of medication and irrigation solutions. CONCLUSIONS: The Visio Scope allows visual control of the extent of the bone defect and enables optical control after removal of concrements and granulation tissue, before possible regenerative measures. Root fractures and furcation invasion can be reliably documented. Optical control guarantees preoperative and postoperative success of treatment.

An update in periapical surgery.

Periapical surgery has largely improved at all levels due to new technologies provided by researchers throughout the last years. The aim of this article is to carry out a bibliographic revision of the last seven years. For this reason, we will analyse the studies published in Medline and the most important Spanish dental magazines. The subjects to investigate are mainly based on the incorporation of ultrasonic root-end, which allow the performance of small and adjusted retrograde cavities; as well as the new filling materials. We also include magnifying glasses or surgical microscope to the work material, plus surgical laser and the application of guided tissue regeneration.

Periapical Microsurgery: The Effects of Locally Injected Dexamethasone on Pain, Swelling, Bruising, and Wound Healing.

INTRODUCTION: The purpose of this prospective, double-blind, randomized clinical trial was to evaluate the postoperative healing of endodontic periapical microsurgery after local administration of dexamethasone. METHODS: Sixty patients were divided into 2 groups. The dexamethasone group received a single local submucosal injection of 4 mg dexamethasone, and the placebo group received a submucosal injection of saline solution at the conclusion of standardized periapical microsurgery. Acetaminophen and hydrocodone/acetaminophen were prescribed for pain relief. A Likert-like 6-point scale was used for self-evaluation of pain, bruising, swelling, and wound healing at 24, 48, 72, 96 hours and at 1 week. The number of tablets taken was registered. Data were analyzed using the chi-square and Fisher exact tests at a significance level of P < .05. RESULTS: No improvements in pain, bruising, and wound healing were registered at any time interval. No difference was found in the number of tablets taken for pain relief. Subjects who received the dexamethasone injection reported less swelling 24 hours after periapical microsurgery (P < .05) but showed no significant benefit for the longer follow-up periods. CONCLUSIONS: This study shows that a 4-mg dose of dexamethasone administered through a local submucosal injection after periapical microsurgery has minimal impact on pain, bruising, and apparent wound healing at any time over a 7-day interval, and the impact on swelling seems limited.

Treatment of large apical lesions with mucosal fenestration: a clinical study with long-term evaluation.

INTRODUCTION: Mucosal fenestration at the root apex may compromise the treatment results of periradicular surgery from exposing the surgical wound to the oral environment. The purpose of this study was to evaluate the long-term outcomes of periapical lesions with mucosal fenestrations treated by guided tissue regeneration (GTR) combined with the management of soft tissue defects. METHODS: Five patients with mucosal fenestration and large periapical lesions were treated by endodontic surgeries and periodontal regenerative procedures during 1999 to 2006. The barrier membranes and osseous grafts were placed over the periapical defects after root end resection and retrograde filling. The mucosal openings in all cases were sutured, whereas a connective tissue graft was placed before repositioning the flap in 2 cases. RESULTS: The cases involving connective tissue grafting showed complete soft tissue coverage, whereas 2 of the 3 cases involving primary closure of fenestrations still had a small soft tissue opening that was further managed by placement of a connective tissue graft beneath in 1 case and direct suturing in the other case. After at least 6 years (72-160 months) of follow-up, all cases showed complete soft tissue and radiographic healing. CONCLUSIONS: Connective tissue grafting in combination with GTR therapy facilitated fenestration closure and ensured long-term success in the treatment of a large periapical bony defect with mucosal fenestration.

Current Concepts of Periapical Surgery.

Preoperative decision-making is vital to determine potential success of periapical surgery. Adequate exposure of the root apical region is best approached via a sulcular-type incision. Surgical procedures include resection of 2 to 3 mm of the apical portion along with root end preparation and seal. The surgeon must decide if submission of periapical tissues to pathology is indicated.

Wound healing in the tissues of the periodontium following periradicular surgery. I. The incisional wound.

Periradicular surgical procedures were performed on rhesus monkeys and the wound healing responses of the tissues of the periodontium were evaluated by light microscopy. This article, Part I of the investigation, reports the mucoperiosteal tissue wound healing responses to incisional wounds of the triangular and submarginal rectangular flap designs. Little difference was found in the temporal and qualitative healing responses to incisional wounds of the two flap designs. However, the submarginal rectangular design showed less predictable results, with a greater intersample variation of wound healing responses in the earlier postsurgical evaluation periods. Vital connective tissue and epithelium, although not visible clinically, remain attached to the root surfaces following reflection of flaps which include an intrasulcular incision. Preservation of these root-attached tissues prevented apical epithelial down-growth along the root surfaces and loss of soft tissue attachment levels. Vitality of root-attached tissues was preserved by preventing dehydration, avoiding curettement of root surfaces, and using a flap reflection technique which eliminates reflective forces in the intrasulcular incisional wound site.

Wound healing after mucoperiosteal surgery in the cat.

The purpose of this study was to examine possible tissue-dependent differences in rate of healing after mucogingival flap surgery. After intrasulcular incision and a vertical-releasing incision distal to the maxillary and mandibular cuspids, buccal, full-thickness mucogingival flaps were raised in four quadrants of 10 adult cats. The triangular flaps were left open for 30 min and then repositioned and sutured. Tissue reactions were studied histologically after 1, 3, 7, 14, and 28 days of healing. Although new collagen occasionally was observed in the wound space in the free gingiva at 3 days, collagenous union between the cut dentogingival fibers and the flap seemed well established at 7 days. Flap reattachment to the denuded cortical bone was seen at 14 days in the region of the attached gingiva. In the region of the alveolar mucosa, however, residual coagulum and inflammatory reaction was present as late as at 28 days in several specimens. These observations indicate a marked difference in rate of healing among the different interfaces involved. These variations seem to be related to variations in size of the resulting wound space when a full-thickness mucoperiosteal flap is readapted over cervical root surfaces, alveolar bone crest, and denuded cortical bone, respectively.

Transillumination of the beveled root surface: an aid to periradicular surgery.

A technique utilizing fiberoptics to transilluminate a beveled root surface during periradicular surgery is described. This procedure when integrated with other standard endodontic surgical aids may help diagnose apical variations and vertical root fractures.

Wound healing in the tissues of the periodontium following periradicular surgery. III. The osseous excisional wound.

Excisional wounds were made in the maxillas and mandibles of rhesus monkeys, and the osseous wound-healing responses at postsurgical intervals ranging from 1 to 28 days were evaluated by light microscopy. The excisional defects were initially filled with a coagulum which was subsequently replaced by granulation tissue emanating from the endosteal tissues. Cortical and trabecular bone forming the wound edges was devitalized, as evidenced by an absence of osteocytes in the peripheral lacunae. At 14 days postsurgery, woven bone trabeculae occupied most of the defect, with the more superficial trabeculae in direct contact with a thick band of dense fibrous connective tissue separating the osseous defect from overlying mucosal tissues. Within the defect, new bone was deposited on devitalized bone without evidence of preceding osteoclastic activity. At 28 days, the woven bone trabeculae were more mature and a functioning periosteum was now active in repair of the cortical plate.