Short-term tissue response to potential root-end filling materials in infected root canals

The short-term tissue responses to two potential root-end filling materials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol), were compared with that to amalgam using a previously devised experimental model. In 24 premolar teeth of beagle dogs (47 roots), a collection of endodontic pathogenic bacteria was first inoculated into the root canals to induce periradicular lesions. On each root, an apicoectomy was performed and root-end cavities prepared to receive fillings of each material. The teeth and surrounding jaw were removed after 2 weeks (23 roots) and 1 week (24 roots); they were then prepared for histological examination. The tissue response to amalgam fillings after 2 weeks and 1 week was marked by moderate or severe inflammation on all roots, and extended to < or = 0.5 mm or > 0.5 mm in 15 out of 16 roots. In contrast, after 2 weeks, the majority of roots filled with Kalzinol showed little or moderate inflammation, while the tissue response to Vitrebond was the best of the three materials, and was also the least extensive. After 1 week, the overall best tissue response was with Vitrebond, followed by Kalzinol. The differences between materials for both time periods with either none or few inflammatory cells when compared with that with either moderate or severe inflammation were not statistically significant (P < 0.02). However, the differences between materials for both time periods with no inflammation or inflammation extending < 0.2 mm when compared with that with inflammation extending > 0.2 mm (< or = 0.5 mm or > 0.5 mm) were statistically significant (P < 0.01). Apart from amalgam, in which healing was marked by the persistence of a localized focus of inflammation adjacent to the root-end filling, even though there were intersample variations, there was little overall difference in the temporal and qualitative healing response to Vitrebond and Kalzinol. Both Vitrebond and Kalzinol have potential as root-end filling materials, as the tissue response was considerably more favourable than that to amalgam even in the short-term.     

Periradicular curettage

Periradicular curettage is a part of the treatment procedure of periradicular surgery. Its main purpose is to remove pathological periradicular tissues for visibility and accessibility to facilitate the treatment of the apical root canal system, or sometimes for the removal of harmful foreign materials present in the periradicular area. Inflammatory periradicular lesions (granuloma and cysts) are the responses of the periradicular tissues to irritants from the root canal and not from the periradicular area unless medicaments and/or filling materials have been forced through the apical foramina or perforations into the periodontium. Histologically, the inflammatory periradicular lesion is similar to healing granulation tissue, which is composed of cells which have natural and specific immunological defence capability and cooperate by means of cytokines to amplify the protective mechanisms of the host. Accordingly, it is not necessary to completely curette out all the inflamed periradicular tissues during surgery, since this granulation-like tissue will be incorporated into the new granulation tissue as part of the healing process. To control the source of irritants in the root canal is far more important than to remove all periradicular tissues affected by the irritants. The successful removal of all irritants from the root canal system results in resolution of pulpally induced periradicular lesions. In the case where the periradicular lesion is caused by endodontic instruments or cytotoxic filling materials placed in the periradicular tissues, removal of these foreign objects is required for resolution of the lesion.     

Periradicular healing in response to Diaket root-end filling material with and without tricalcium phosphate

The healing of the periradicular tissues was evaluated when the polyvinyl resin Diaket with and without tricalcium phosphate was used as surgical root-end filling material. Non-surgical root canal treatment was performed on 56 mandibular premolar roots in mongrel dogs. Following root-end resection, root-end cavity preparations were filled with Diaket, the comparative material, or Diaket in combination with tricalcium phosphate, the experimental material. Postsurgically, healing of the tissues adjacent to the filling materials and in the surrounding surgical site were evaluated at 30 and 60 days. There was virtually no statistically significant difference between the experimental and comparative group at or within the 30- or 60-day period with regard to inflammation, connective tissue formation, root-end encapsulation, cementum formation, or bone apposition. Findings suggest that cementogenesis occurred over both materials. The overall healing of the periradicular tissues was favourable.     

Effects of resorbable membrane placement and human osteogenic protein-1 on hard tissue healing after periradicular surgery in cats

Periradicular surgeries were performed on the maxillary cuspid teeth of twelve cats. Before reapproximation of the surgical flaps, eight of the osteotomies were covered with a resorbable membrane and eight were filled with human osteogenic protein-1 (hOP-1) on a collagen carrier. The remaining eight sites received no further treatment and served as controls. The animals were euthanized after 12 wk, and the specimens were examined histomorphometrically for the presence or absence of osseous regeneration, inflammation, and cementum formation on the root ends. The results showed that the sites treated with the membrane exhibited significantly more inflammation adjacent to the resected root ends (p < 0.05), and that the use of the membrane had no statistically significant effect on osseous healing or new cementum formation. The use of hOP-1 was associated with a significant decrease in the thickness of new cementum formed on the resected root ends (p < 0.05), but had no statistically significant effect on osseous healing or degree of inflammation. Based on these results, it seems that neither the use of hOP-1 nor resorbable membranes have a positive effect on periradicular tissue healing in endodontic surgery.     

Frameless stereotactic-directed tissue sampling during surgery of suspected low-grade gliomas to avoid histological undergrading

OBJECTIVE: To determine if the clinical and radiographic presentation of patients referred by their general dental practitioner requesting periradicular surgery fulfilled a set of predetermined guidelines as to the appropriateness of the procedure. DESIGN: Multicentre prospective study. SETTING: Maxillofacial departments of district general hospitals. METHOD: Consecutive analysis of referrals within four hospitals over a 1-year period between 1995 and 1996. RESULTS: From 205 referrals, mostly of patients in the 30 to 40 years age group, 79.5% (n = 163) of referrals failed to meet the criteria, mainly because of an unsatisfactory root canal filling, but also due to obvious coronal microleakage and adjacent teeth contributing to the disease process not yet having received endodontic treatment. In only 6.3% (n = 13) of patients had there been an attempt to retreat the pulp space infection by conventional means. CONCLUSION: The majority of referrals in this study did not fulfil the guideline criteria on the provision of periradicular surgery. The factors influencing failure in endodontics and periradicular disease did not appear to have been appreciated, or were not acted upon. Conventional retreatment of the pulp space needs to be considered or attempted prior to referral for surgery.     

Artificial caries formation around fluoride-releasing restorations in roots

Secondary caries is one of the most important factors leading to replacement of dental restorations. This investigation assessed the capacity of fluoride-releasing restorative materials to resist caries in vitro when used in roots. Class 5 cavities were prepared in the buccal and lingual surfaces of 30 extracted premolars. The six materials used were: glass-ionomer cement (Fuji), glass-ionomer cement with silver particles added (Ketac-silver), fluoride-containing composite resin (Tetric), composite resin (Silux plus), fluoride-containing amalgam (Fluor-Alloy) and high-copper amalgam (Dispersalloy). After 5 weeks in an acid gel for caries-like lesion formation, the teeth were sectioned longitudinally and examined with polarized light. The results showed that repair with glass-ionomer materials of a carious lesion may be of great importance in the prevention of secondary caries around the restorations in roots.     

Adhesion receptors on bone marrow stromal cells: in vivo expression of vascular cell adhesion molecule-1 by reticular cells and sinusoidal endothelium in normal and gamma-irradiated mice

Periradicular surgery combined with final laser sterilisation was performed on 62 teeth of 50 patients by 3 trained oral surgeons, according to a well defined treatment protocol. It concerned a 5 Watt continuous wave CO2-laser. After a follow-up period ranging from 6 to 17 months all patients were recalled. 28 patients (56%) or 33 teeth (53%) could be evaluated. The success rate was determined by a questionnaire, a standard clinical examination and an X-ray evaluation. Complete surgical healing was found in 59% of the teeth and incomplete healing in 23%. Uncertain healing and unsatisfactory healing were observed in respectively 11% and 7% of the teeth. Better healing results were found in elements with one endodontic canal (67% complete healing) and when endodontic treatment was combined with the intervention (71% complete healing). Comparison of the results of the present study with comparable studies without laser sterilisation, showed however no statistical significant improvement.     

The experience of a clinical trial of bioceramic-based materials in dentistry

Bioceramics-based materials manufactured in Russia were experimentally and clinically tried with the aim of optimizing repair osteogenesis of the jaws. Powder, granules, and porous blocks of hydroxyapatite alone and mixed with tricalcium phosphate may be effectively used for plastic repair of osseous pouches and post-operative defects of the jaws in surgical treatment of periodontitis, periradicular cysts of the jaws, and for filling the wells after removal of teeth.     

Use of the operating microscope in dentistry

Microsurgery is a discipline of multiple surgical procedures performed with optical magnification and illumination. The operating microscope has recently been introduced in dentistry. Magnification improves the performance of fixed prosthodontic laboratory and clinical procedures. The operating microscope has dramatically improved endodontic nonsurgical perforation repair and periradicular surgery. The use of the operating microscope and microsurgical instrumentation has resulted in more-precise periodontal surgical procedures with less operative trauma and improved healing. Use of the operating microscope and microsurgical instrumentation is described.     

Postoperative complications after Mainz pouch construction--with emphasis on measures to deal with narrowing of the duct aperture

Cutaneous sinus tracts in the face and neck region are often dental in origin. The purpose of this study was to characterize the clinical features and treatment of 37 consecutive cases of odontogenic cutaneous sinus tracts, collected and reviewed in a 15-year period. More than half of the patients (21 cases, 57%) were referred from medical doctors, particularly plastic surgeons and dermatologists. The sinus tracts were associated with caries (26 cases), incomplete endodontic treatment (7), crown fracture (2), vertical root fracture (1) and impacted mandibular third molar (1). They occurred most often in adolescents and adults (30 cases, 81%). The most common causative teeth were mandibular teeth (34 teeth, 85%). The chin, submental, and cheek areas were the most common sites of sinus tracts (30 cases, 81%). The majority of causative teeth (32 teeth, 80%) were treated endodontically. All fistulas healed uneventfully after proper dental treatment, without cosmetic surgery. In 63% (20 cases) of the recorded cases, complete resolution occurred within 8 weeks. Half of the patients had had fistulas for more than 6 months before receiving dental treatment, demonstrating that delays in proper diagnosis and treatment were common. As most patients suffered from unnecessary medication or surgery due to the delay of dental treatment, early dental consultation and treatment is important. Conventional endodontic treatment should be the treatment of choice if the tooth is salvageable. The increasing incidence of incomplete endodontic treatment in association with the occurrence of sinus tracts indicates that standardized endodontic therapy should be emphasized for prevention.     

Comparative study of two filling techniques using glass-ionomer (Ketac-endo) root canal cement on fracture resistance of endodontically treated roots (in vitro)

Forty freshly single rooted teeth were selected for this study. The coronal part of teeth were decapitated and the root canals were prepared by modified step-back technique with K-flex files to size 35# at the apex, five ml of 5.25% NaOCl was used as irrigating solution. According to the dentin thickness at the mesio-distal direction of the prepared roots, roots were divided into two groups: Group (I), dentin and cementum thickness from 1.5-2 mm, and Group (II), dentin and cementum thickness 1 mm. According to the filling technique used the teeth were subdivided into four subgroups each of five teeth; Subgroup (A) single gutta-percha cone and Ketac-endo root canal sealer, Subgroup (B) lateral condensation technique with gutta-percha and Ketac-endo sealer, Subgroup (C) laterally condensed gutta-percha with Roth 801 cement and Subgroup (D) teeth left unfilled as negative controls. The prepared roots were placed into acrylic resin so that 10 mm of the root was exposed. A slowly increasing force was applied vertically using a blunt punch with 1 mm tip thickness attached to Instron testing machine. The results showed that group (I) with 1.5-2mm dentin thickness required greater force to fracture in all experimental groups, than that of group (II) with 1 mm dentin thickness. So the amount of remaining dentin thickness significantly affected the resistance to fracture of the prepared roots.     

The management of thermomechanically compacted gutta percha extrusion in the inferior dental canal

Endodontic material inadvertently forced into the inferior dental canal during root-canal therapy can cause damage to the underlying nerve. The effect of toxic filling materials on nervous tissues has been well publicised, however, the thermal and pressure changes produced by chemically bland materials has not been adequately highlighted. In the case reported, thermoplasticised gutta percha was inadvertently introduced into the canal during endodontic treatment of a lower molar. Factors affecting the outcome are discussed and guidelines are presented for the management of such a case with reference to surgery against observation.     

Management of a maxillary canine with dens invaginatus and a vital pulp

A case is presented that demonstrates successful management of a maxillary canine with dens invaginatus (Oehlers' type 3 invagination) with associated chronic periradicular periodontitis and a vital pulp. Debridement and obturation of the invaginated space resulted in resolution of the associated periradicular radiolucency. Pulp vitality was retained after endodontic treatment of the invagination.     

Ultrasonic root-end preparation: influence of cutting angle on the apical seal

Apical resection is fundamental in obtaining a correct apical seal. The purpose of this study was to evaluate how the apical root resection angle and the cavity made by ultrasonic retrotips may influence the apical seal. A total of 48 extracted teeth were endodontically treated and sealed by guttapercha vertical compaction: 24 were resected with a 45 degrees angle and 24 with a 90 degrees one. An ultrasound source (P.M. 400 EMS) and a CT5 Scaler were used to make the retrograde cavity that was filled afterwards with EBA-zinc oxide-eugenol alumina-added cement. Apical leakage was determined using fuchsin and assessed after the roots were sectioned longitudinally. Linear dye penetration in dentin and at the interface between dentin and cement was measured with a stereomicroscope (x 12 magnification), and the results were statistically analyzed. Results showed that there was less infiltration both in dentin and in the space between the filling and the dentinal wall in the group with the 90 degrees angle, but this difference was statistically significant (p < 0.0001) only for the dentin. None of the samples showed leakage greater than the depth of the preparation. An apical cavity of 3 mm or more along the vertical axis can produce a safe and effective seal.     

Delayed endodontic and orthodontic treatment of cross-bite occurring after luxation injury in permanent incisor teeth

A case is presented in which combined endodontic and orthodontic therapy was performed in traumatically injured teeth 12 months after an accident. Calcium hydroxide treatment was used to halt any possible resorption during orthodontic treatment. The teeth were repositioned in a desirable manner without any complication by orthodontic treatment. Root canal obturation was accomplished after the completion of active orthodontic treatment. Recall examination 12 months after completion of root canal treatment showed clinical and radiographic evidence of healing.     

Controversies in clinical endodontics: Part 2. Single-appointment vs multiple-appointment treatment

Endodontics is no stranger to controversies. For most of the first 50 years of the 20th century, a cloud hung over endodontic therapy of any kind, as problems with the focal infection theory were attributed to pulpless teeth causing a wide variety of maladies. Even recently, endodontic treatment has been attacked as being responsible for many chronic and acute illnesses, despite a multitude of information to the contrary. The controversies we discuss here, however, have nothing to do with the decision to treat, where we have no doubt as to the efficacy for therapy, but rather how such treatment should be rendered. Controversies have raged in the past, such as silver points vs gutta-percha as the canal filling material of choice, and to culture or not to culture, to name just two. The subjects discussed in this series of articles are those that have come up much more recently or older topics that have returned as areas for disagreement: (1) lateral canals: filling and significance; (2) single-appointment vs multiple-appointment treatment; (3) filling from the open position; and (4) calculation of working length. This article addresses single-appointment vs multiple-appointment treatment.     

Impedance of pacemaker leads: correlation of different methods

PURPOSE: Four children with an osteomyelitic process in the jaw bones while on cytotoxic chemotherapy were treated by radical surgery and antimicrobial chemotherapy. PATIENTS AND METHODS: Symptoms (local swelling and pain in the jaw, necrotic gingivitis, and spontaneous loss of teeth) appeared 3 weeks, 4 weeks, and 8 months after diagnosis of leukemia, and 8 days posttransplant in a patient with severe aplastic anemia. Three had the process in the mandible and one in the maxilla. Specific diagnoses of Aspergillus flavus, Saccharomyces cerevisiae, and Actinomyces species were obtained histologically from surgical samples. Treatment was radical surgery to remove all infected and necrotic tissue: removal of a substantial part of the mandible and loss of seven to eight permanent teeth in those with mandibular lesions. Actinomycosis was treated with penicillin for 2 years. The patients with fungal lesions received amphotericin B for 2, 5, and 6 months, with adjuvant itraconazole, fluconazole, or 5-fluorocytosine for 9-12 months. Anti-cancer chemotherapy was continued. RESULTS: All the bony lesions healed. The patient with acute myeloid leukemia died in relapse 1 year postdiagnosis; her aspergillus osteomyelitis had been inactive for 8 months. The other three patients are alive and well 1.9, 2.1, and 1.9 years after termination of antimicrobial therapy. CONCLUSIONS: We emphasize the necessity of specific diagnosis from appropriate surgical samples and conclude that in patients undergoing chemotherapy bony lesions caused by opportunistic microorganisms may be curable with aggressive surgery and prolonged medication.     

Regional variation in root dentinal tubule infection by Streptococcus gordonii

The purpose of this study was to investigate the pattern of bacterial invasion of dentinal tubules at different regions in human roots. Specimens were obtained from single-rooted teeth that had their root canals prepared in a standard manner. Roots were then sectioned longitudinally through the canals and the resulting specimens chemically treated to remove the smear layers. Specimens were immersed in a suspension of Streptococcus gordonii for 3 weeks and then prepared for histological analysis. Sections from the cervical, midroot, and apical areas were examined. The pattern of bacterial infection of the cervical and midroot areas was similar, characterized as a heavy infection with bacteria penetrating as deep as 200 microns. Invasion of the apical dentin was significantly different, with a mild infection and maximum penetration of 60 microns.     

Intrusive thoughts and avoidance behaviors are associated with sleep disturbances in bereavement-related depression

Three methods for temporarily filling root canals with calcium hydroxide pastes were compared. Each of 20 root canals of extracted, human, single-rooted teeth was shaped with hand instruments under standardized conditions up to ISO size 50 and filled using a syringe system, a lentulo spiral or an endodontic reamer. Quality of fillings was assessed radiographically and by inspecting ground preparations. Ridit (relative to an identified distribution) analysis was employed to confirm differences in frequencies of certain quality criteria obtained with various application methods. With regard to degree of obturation and occurrence of porosities, application of temporary fillings with a lentulo spiral or syringe system revealed significantly better results than application with hand instruments (reamer). No differences with regard to degree of obturation were detected when comparing results obtained with syringe or lentulo. Fewer porosities in the apical part of the root canal were seen, both on radiographs and ground sections, with the syringe system compared with the lentulo spiral. In the presence of some contradictory reports found in the literature, the present study suggests that, after straight or slightly curved root canals have been shaped up to at least ISO size 50, high quality temporary root canal fillings may be obtained by application of an aqueous suspension of calcium hydroxide with a syringe system.     

Low-frequency ultrasound treatment of chronic venous leg ulcers in an outpatient therapy

An in vitro dye leakage study was performed to compare the sealing ability of glass ionomer, composite resin and glass ionomer/resin cement when used as restorative materials for G.V. Black class V cavities. In this research, standard Class V cavities were prepared in sound premolar teeth extracted for orthodontic reasons. The cavities were randomly divided into 3 groups. After filling the cavities with glass ionomer cement, composite resin and light curing glass ionomer/resin cement, the specimens were immersed in silver nitrate solution. Marginal microleakage at the interface between the cavity wall and restoration was evaluated. The results were analyzed by using Kruskal-Wallis and Mann Whitney U tests. Result of this in vitro study indicate that composite resin and glass ionomer/resin cement provide a better seal than glass ionomer cement.