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.     

Incomplete calcium hydroxide removal from the root canal: a case report

This case demonstrates failure of root canal treatment of a maxillary central incisor following incomplete mechanical removal of a Ca(OH)2 intracanal dressing and subsequent resorption of the material from the apical portion of the root canal. Retreatment some 4 years later involved the removal of the contents of the root canal and permanent obturation by lateral condensation of cold gutta-percha with a sealer. Follow-up showed complete periradicular bone healing with a lamina dura evident. An explanation of the processes involved is offered, based upon histopathological and microbiological evidence in the literature.     

Cholesterol 7 alpha-hydroxylase activity in hypothyroidism and hyperthyroidism in humans

The effects of three root-end filling materials on healing following endodontic surgery were assessed radiologically and correlated with histological findings reported elsewhere. The materials compared were a light-cured glass ionomer cement (Vitrebond), a reinforced zinc oxide-eugenol cement (Kalzinol) and amalgam. The root canals of 27 two-rooted mandibular premolar teeth of six beagle dogs were inoculated with endodontic pathogenic bacteria to induce periradicular lesions. The roots were apicected and root-end cavities filled with the tested filling materials. The teeth and surrounding jaw were removed after 4 weeks (30 roots) or 8 weeks (24 roots). Radiographs were taken of each jaw section and subjected to image analysis. Healing was evaluated based on measurements of the size of the periradicular radiolucent areas. ANOVA disclosed no statistically significant differences in the size of the periradicular areas either between time periods or between materials. These results did not correlate with the tissue responses in the same material as assessed histologically and previously reported. The use of radiographs alone to assess healing after endodontic surgery in the dog mandible is unsatisfactory, and should not be regarded as a substitute for histological examination for the determination of healing.     

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.     

Suicidality and aggressive behaviour

Delayed wound healing is one of the complications of diabetes mellitus, exhibited by increased wound collagenase and decreased granulation tissues. The current study compared wound healing in normal and diabetic rats, and the effects of topically applied 1% or 3% concentrations of chemically modified tetracycline-2 (CMT-2) on 6-mm circular full-thickness skin wounds healed by secondary intention. On day 7 after wounding, tissues were removed for biochemical analysis and histology. The wound granulation tissue hydroxyproline was less in the untreated diabetic rat with increased collagenase and gelatinase. Treating the diabetic rat wounds with 3% CMT-2 increased the wound hydroxyproline and decreased activities of gelatinase and collagenase. There was a delay in wound filling by granulation tissue in diabetic rats. In CMT-2-treated diabetic rats, the volume of granulation tissue was greater than that in untreated diabetic rats. CMT-2 appears to normalize wound healing in diabetic rats and may be a valuable adjunct in the treatment of chronic wounds.     

Histological evaluation of therapy using a calcium hydroxide dressing for teeth with incompletely formed apices and periapical lesions

Periapical tissue response was evaluated histologically in teeth of 6-month-old dogs with incomplete root formation and periapical lesions in order to compare the effects of two calcium hydroxide-containing pastes prepared with different vehicles on induced root apex formation and repair of the periapical region. A group of teeth with no root canal dressing was used as control. After induction of the periapical lesion, the root canals were instrumented and filled with one of the two pastes (Calen and Calasept), which were renewed monthly for 90 days. At the end of the follow-up period (3 months), the animals were killed. Block sections from the actual areas were dissected free and prepared for histopathological analysis. Both calcium hydroxide pastes helped induce apical sealing and repair of the region, but the Calen paste yielded better results than Calasept. The induced mineralized tissue was predominantly of the cementoid type after the use of both pastes, but the inflammatory infiltrate was significantly less intense with the use of the Calen paste. In the control group, the absence of a root canal dressing impaired the process of periapical repair and yielded no apical root closure in any of the cases analyzed.     

Hidradenitis suppurativa

BACKGROUND: Hidradenitis suppurativa (HS) is a recurrent, suppurative disease manifested by abscesses, fistulas, and scarring. METHODS: We reviewed the literature to identify reliable information regarding epidemiology, pathogenesis, clinical manifestations, evaluation and differential diagnosis, treatment, complications, and prognosis. RESULTS: Hidradenitis suppurativa usually affects young women, with a prevalence of 0.3% to 4% in industrialized countries. Once considered to be "apocrine acne," HS is actually a defect of terminal follicular epithelium. Obesity, chemical irritants, or hyperandrogenism are not consistently associated; bacterial involvement is secondary. Hidradenitis suppurativa should be suspected in young adults with recurrent, deep furuncular lesions in flexural sites, especially when such lesions respond poorly to antibiotic therapy. Clindamycin and isotretinoin may be useful, though wide excision with healing by granulation is considered most efficacious. Anemia, arthropathy, and squamous cell carcinoma are potential complications. CONCLUSIONS: Since spontaneous resolution is rare and progressive disability the rule, early definitive surgical treatment of HS is advisable.     

Appendiceal ultrasonography performed by nonradiologists: does it help in the diagnostic process?

OBJECTIVE: In this study, the effects of pulsed Nd:YAG laser irradiation during root canal treatment of infected teeth were investigated histopathologically in dogs. SUMMARY BACKGROUND DATA: Effects of Nd:YAG laser on infected root canal treatment have not been reported in vivo. METHODS: One hundred thirty-five teeth with a single root, including incisors and premolars, in 15 healthy adult beagle-strain dogs were used in this study. After inducing infection in the teeth, each root canal was shaped with at least a # 40 K-file, then the canal was irradiated using the following parameters: 1 W, 30 pps for 1 and 2 sec; 2 W, 30 pps for 1 and 2 sec. Efficacy of debris removal and evaporation on the root canal walls at 2 weeks, and the degree of inflammation of the periapical region at 2, 4, and 8 weeks after laser irradiation were examined histopathologically by light microscopy. RESULTS: Effective debris removal was observed in all cases of the laser-treated groups. No evaporation was observed except at the conditions of 2 W for 2 sec. Inflammation of periapical region in the laser-treated groups was similar in the control group at 2 weeks, but was significantly less than that in the control group at 8 weeks (p < 0.05). CONCLUSION: These results suggest that pulsed Nd:YAG laser is useful for one-visit root canal treatment of infected teeth in dogs, if appropriate parameters are selected, and this is a potential therapy for human apical lesions of teeth.     

Changes in cell proliferative activity in granulation tissue invading the root canal

Root canal models were implanted in rats in order to investigate histologically the movement of granulation tissue invading apical canals and dead spaces and changes in cell proliferative activity as indicated by 3H-thymidine. The models were prepared to have 1, 2, and 3 mm apical canals, with and without dead spaces, to simulate preparations short of the apex and obturation to several levels. After 12 wks implantation of the models without dead spaces, granulation tissue invading 1 mm apical canals did not degenerate and cell proliferative activity remained high. However, tissue invading the 2 and 3 mm apical canals tended to be necrotic and cell proliferative activity was decreased. In the models with dead spaces, the tissue in the 1 and 2 mm apical canals developed and invaded the dead spaces, and still possessed proliferative activity 12 wks after implantation. In contrast, the tissue in the 3 mm apical canals did not invade the dead spaces, even after 12 wks, and no proliferative activity was observed.     

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.     

Monitored cicatrization

Directed healing is a therapeutic process that Raymond Vilain conceived as a sequence of: cleaning, granulation and formation of the epidermis. He suggested, to aid healing, the use of sofra-tulle and washing with isotonic solution or tap water, we have added the use of a hair dryer, in order to decrease the exudation from the wound. Such directed healing is particularly of interest for the integument and is difficult to apply to such structures as fat, fibrous tissues, bone and cartilage, or nerves and vessels. The "star" of directed healing is the granulation tissue. If healthy, it will support progressive marginal formation of the epidermis if the loss of tissue is not too great; if this loss is extensive, a graft will easily take on top of the layer of granules. If abnormal, the granules will lack tone. Healing will have to be renewed by appropriate treatment. We are all programmed to heal, except if we hinder the process by technical and psychological errors.     

Effects of dental trauma on the pulp

Infection of the root canal system following dental trauma induces pulp and periapical disease and prevents healing of previously healthy pulp. A clinical goal in treating trauma is the maintenance of pulp vitality, and clinicians should be aware of factors that influence pulp healing. The learning objective of this article is to review the factors and techniques that influence pulp vitality and examine the influence pulp has on the healing of adjacent tissues. The potential routes for bacterial infection of the root canal system are discussed, with the clinical crown as the primary portal of entry. Uncomplicated and complicated crown fractures, as well as the crown-root and root fractures, are reviewed. Complications in pulp healing include canal obliteration, disturbed root development, apexogenesis, apexification, and the various forms of resorption.     

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.     

Factors determining the outcome of scaling and root planing

Scaling and root planing are the predominant and recognized forms of periodontal therapy. They have been known for centuries, and have been investigated with increasing intensity since the turn of the century. Scaling and root planing aim at therapeutic changes of the "hard tissue lesion" at the root surface, in order to render it biologically acceptable to cells capable of attaching to it. Two major components of these root surface alterations are calculus and cementum alterations. Numerous studies have shown that scaling and root planing effectively removes subgingival deposits, and that this removal is seldom complete in deeper pockets. Even though beneficial clinical effects of scaling and root planing have been shown, it is unlikely that the full potential of healing is utilized today due to technical shortcomings. Several studies have shown that the design and dimensions of curets as used today are not optimal. These instruments are for many situations too big, subject to rapid dulling, and produce a smear layer. Chemical agents have been used to remove this layer with limited success. The therapist is a virtually unknown factor in the system of delivering scaling and root planing. A recent study showed that scaling and root planing forces used by different therapists on similar root surfaces varied by factors greater than 10. In addition, higher forces were shown to remove significantly more root substance. Apparently there is a large subjective component included in the delivery of scaling and root planing therapy. Even though scaling and root planing have been shown to be effective therapeutic procedures, many aspects require more research.     

Effect of root canal contents on healing of teeth with dentin-bonded resin composite retrograde seal

Healing results were compared among 551 infected roots apically sealed with a dentin-bonded resin composite (Gluma-Retroplast). These roots contained either 1) root filling to apex after resection, 2) insufficient root filling, or 3) empty root canals with necrotic pulp remnants. At 2- to 4-yr follow-up, complete bone healing was found to be 92%, 85%, and 81% in groups 1, 2, and 3, respectively. The results from groups 1 and 3 were significantly different, and the results from group 2 did not differ significantly from that of groups 1 or 3. Reasons for "Failures" were found to be mainly loose filling or uncovered canal. After 21 roots classified as "Failures" were reoperated, 76% of these showed "Complete Healing" after 1 yr.     

Prevalence and depth of artificial caries-like lesions adjacent to cavities prepared in roots and restored with a glass ionomer or a dentin-bonded composite material

One potential advantage of glass-ionomer materials for the treatment of root caries is their ability to release fluoride and so resist cariogenic attack. A commercially available composite material has also been reported to release fluoride which reduced caries lesions in the tooth tissue adjacent to it. The aim of this study was to assess the effectiveness of a conventional glass-ionomer restoration compared with a dentin-bonded, fluoride-releasing, composite restoration when exposed to a microbial artificial caries system. Artificial caries-like lesions produced in relation to the restorations were examined and classified either as outer (surface) lesions or as wall lesions. A split-unit experimental design allowed for within-tooth comparisons of the 2 experimental restorations at different sites on the root surface. These were either totally within the root surface or positioned at the amelo-cemental junction. Outer lesion depths were significantly (p < 0.001) shallower at all sites adjacent to the glass ionomer when compared with the composite restorations. Wall lesions were significantly (p < 0.01) more prevalent adjacent to the composite material. In addition, the cavity margin position significantly (p < 0.05) affected the incidence of wall lesions, particularly in the composite group. In conclusion, glass ionomer was successful in reducing the caries-like lesion production in the adjacent root surface. This resulted from improved marginal integrity and fluoride release from this material when compared with the composite bonding system used.     

Microbiology of tracheal granulation tissue associated with silicone airway prostheses

Granulation tissue formation and contraction is inevitable during the healing of open wounds. The presence of infection and a foreign body, such as a silicone airway prosthesis or other tracheotomy tube, magnifies this response. In airway reconstruction, wound contraction secondary to chronic inflammation is a liability. Cultures of granulation tissue were taken from 12 patients with silicone cannulas of T-Tubes. Polymicrobial colonization predominated, with variable combinations of gram-positive, gram-negative, and anaerobic organisms being present. On the basis of sensitivity data, amoxicillin-clavulanate potassium and ciprofloxacin hydrochloride were chosen as empirical antimicrobials. Anecdotally, impressive decreases in the quantity of granulation tissue were seen. We recommend a prospective trial to more accurately define the role of antibiotics in this setting.     

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.     

Arrest of root surface caries in situ

This study tests the hypothesis that daily oral hygiene combined with topical fluoride arrests active root-surface caries lesions without changing the mineral content of the lesions. Therefore, changes in mineral content and distribution were studied in root surfaces during caries lesion development and subsequent arrest of lesion progression in situ. In 18 subjects, lesions were developed during 3 months in sound root-surface specimens inserted into lower partial dentures. After 3 months, ground sections were prepared from each lesion prior to re-insertion of the specimens into the dentures. In addition, one sound root specimen was added per subject. During the following 3 months, half of the subjects cleaned both sound and carious specimens once a day with an 1100-ppm fluoride toothpaste, and the specimens were treated twice with 2% NaF for 2 min in situ. The other half of the subjects continued the experiment without cleaning. During the initial three-month period, all specimens developed subsurface lesions extending 187 to 583 microm into the dentin. Lesion depth increased somewhat in both experimental groups during the following 3 months (P > or = 0.1). There was a non-significant increase in mineral loss in the plaque-covered specimens (P = 0.08). However, the total mineral content of specimens subjected to plaque removal and topical fluoride did not change. This treatment resulted in an increased mineral content in the surface layer (P < 0.01) and formation of a zone of higher mineral content within the body of the lesion. The sound root surfaces which had been cleaned for a three-month period showed mineral uptake in the surface layer, occasionally associated with subsurface demineralization extending 20 to 70 microm into the tissue. The mineral loss of these specimens was significantly smaller than that of plaque-covered surfaces (P < 0.001). It is concluded that daily plaque removal and topical fluoride use influence the distribution of mineral in sound and carious root surfaces and may arrest lesion progression without affecting the total mineral content.