Management of tooth resorption.

A correct diagnosis and an understanding of the aetiology and dynamics of the processes involved in tooth resorption is critical to effective management. Tooth resorptions can be classified as: (1) trauma induced; (2) infection induced; or (3) hyperplastic invasive. Some transient trauma induced resorptions require no treatment but must be carefully monitored to check that there are no complicating issues such as infection. In cases of trauma induced replacement resorption, a multidisciplinary approach is usually necessary to ensure an optimal long-term solution. Infection induced tooth resorptions require the removal of the invading micro-organisms by endodontic therapy including intra-canal medication which can also facilitate repair of the resorbed tooth structure. The hyperplastic invasive tooth resorptions pose considerable challenges in management due to the complexity and aggressive nature of the resorptive process. With careful case selection and complete inactivation of resorptive tissue successful management can be achieved.

Evaluation of a combined thiourea and hydrogen peroxide regimen to bleach bloodstained teeth.

BACKGROUND: Current techniques for intra-coronal bleaching of stained root-filled teeth employ oxidative bleaching with hydrogen peroxide. However, concern over the potential for invasive cervical resorption following the use of hydrogen peroxide has been expressed by many researchers, and recommendations have been made to limit the use of this agent. A reductive-oxidative bleaching process using a thiourea and hydrogen peroxide regimen is proposed as an effective and safer bleaching combination. The efficacy of this novel bleaching regimen is evaluated in this study. METHODS: The study involved a quantitative and qualitative spectrophotometric assessment of the ability of two amine (bleaching) agents, aqueous thiourea and acidified thiourea, to alter the absorption spectra of haemoglobin and methaemoglobin compared to hydrogen peroxide. In addition, extracted premolar teeth discoloured by blood were subjected to different bleaching regimens using amine reducing agents and hydrogen peroxide. The change in the colour of the bloodstained dentine samples was measured at each stage of the bleaching process with a Photometer and Reflectance Densitometer. Comparisons of different treatments were made using a method of least significant difference and/or analysis of variance. RESULTS: Spectrophotometric studies showed that acidified thiourea solution greatly reduced the colour of the haemoglobin and methaemoglobin in the visible range (330-760 nm). Aqueous thiourea had no effect on the presence of haemoglobin and methaemoglobin. Reflection Densitometer and Photometer scores indicate that the greatest bleaching effect was achieved by the combined acidified thiourea and hydrogen peroxide regimen. CONCLUSION: The recognition that bleaching discoloured teeth is a chemical process, which can be achieved by both reducing and oxidizing agents, offers the possibility of developing new and safer clinical bleaching protocols. It is concluded that the bleaching regimen which employs the sequential use of 0.1 M acidified thiourea and 30% w/v hydrogen peroxide is as effective at bleaching bloodstained dentine as 30% w/v hydrogen peroxide alone. However, the addition of thiourea to the bleaching regimen has the potential benefit of reducing the level of damaging hydroxyl radicals and achieving a safer bleaching process.

External tooth resorption associated with a peripheral odontogenic fibroma: review and case report.

The purpose of the study is to document a rare case of a peripheral odontogenic fibroma with associated cervical and coronal tooth resorption in a 38 year old woman. Histopathological features are described, the clinical management outlined and follow-up observations over 27 years detailed. The exophytic firm lesion, coral pink in appearance, located on the labial aspect of a maxillary right lateral incisor was excised, fixed in formalin and prepared for histological evaluation. The resorption cavity and adjacent soft tissue were treated by the topical application of trichloroacetic acid prior to restoration with a glass-ionomer cement and subsequent root canal treatment. Histologically, the body of the lesion was characterized by the presence of odontogenic epithelium embedded in a mature fibrous stroma. Areas of dystrophic calcification could also be identified. The features were consistent with a diagnosis of a peripheral odontogenic fibroma. The clinical result of treatment assessed 27 years postoperatively showed no evidence of recurrence of the peripheral odontogenic fibroma. External cervical and coronal tooth resorption can, on rare occasions, prove to be a clinical feature associated with peripheral odontogenic fibroma. Treatment of the tumour mass and the resorptive lesion can provide a successful outcome.

Life cycles of traumatized teeth: long-term observations from a cohort of dental trauma victims.

Life cycles of dental trauma victims can provide important clinical information, especially when viewed over many years. In this first series of life cycles, the pulp and periodontal responses to traumatic injuries of four patients are documented over periods varying from 26 to 51 years. The dynamics of pulp survival following an intrusive luxation and two avulsions are followed, with particular reference to pulp canal calcification to which a new term, root canal stenosis, has been proposed. The life cycles include the successful management of inflammatory root resorption in a replanted tooth with an open apex contrasting with the early prophylactic endodontic treatment of two replanted teeth in a patient with mature apices. The long-term development of invasive cervical resorption in one of the patient's life cycle highlights the importance of ongoing follow-up examinations for dental trauma victims.

Life cycles of traumatized teeth: long-term observations from a cohort of dental trauma victims - series 2.

In this the second of a series of life cycles of dental trauma victims, the short and particularly long-term responses of four survivors of either multiple luxation injuries or avulsions have been documented over periods varying up to 41 years. The development of ankylosis, either in the short or longer term post trauma, proved a common feature in the series and management strategies have been outlined. External invasive resorption was also identified as a complicating response for which the topical application of trichloracetic acid, intracanal dressing and root canal obturation proved effective in resorption management. Long-term observations indicate that some compromised teeth can be functionally and aesthetically retained for extended periods, but follow-up examinations are important so that treatment interventions can be implemented if adverse responses are diagnosed.

Splinting of teeth following trauma: a review and a new splinting recommendation.

With advances in the understanding of healing processes of the periodontium, pulp and alveolar bone following various injuries, the role of splinting has become relatively well defined. This is generally reflected in the guidelines for trauma management published by the International Association of Dental Traumatology. While the widespread use of composite resin as an adhesive in various functional/flexible splinting systems has over many years allowed ease of application, removal of the material is not only time consuming but more seriously accompanied by minor or major iatrogenic damage to enamel. Dental materials science has continued to provide new materials and amongst them the development of resin activated glass-ionomer cement suitable for orthodontic bracket cementation has allowed the development of an alternative simplified splinting regimen for traumatized teeth which offers ease of application and removal with minimal or no iatrogenic damage to enamel.

Replantation of avulsed teeth. A review.

Time is a critical factor in successful replantation. The avulsed tooth is simply washed and replaced immediately. Where contamination with soil occurs anti-tetanus prophylaxis is given and some form of splinting is necessary for 3-4 weeks. Endodontic therapy is performed prior to replacement if there is a delay of more than two hours and where apex formation is complete it should be commenced within 10 days. Calcium hydroxide is useful as a root canal dressing and in controlling resorption. The value of immediate replacement and treatment should be publicised.

Endodontic education.

Undergraduate endodontology is taught in Australian Universitiies in Restorative or Conservative departments. Courses generally consist of twelve lectures, three seminars and technique courses. Average clinical experience is six to eight endodontic treatments in anterior and posterior teeth. Comparison with American and Scandinavian teaching, staff and facilities indicates that this subject is receiving considerably less emphasis in Australia. As endodontic therapy is eseential in any dental health programme based on preventive dentistry there is a considerable need to upgrade undergraduate endodontic teaching in Australia.

Incidence of invasive cervical resorption in bleached root-filled teeth.

Invasive cervical resorption, a form of external root resorption, has been reported to be associated with intra-coronal bleaching of root-filled teeth and this has raised concerns about carrying out such bleaching procedures. The purpose of the present study was to examine the incidence of invasive cervical resorption in root-filled teeth which had been bleached using a standardized technique. Three observers examined records and radiographs from a total of 158 patients, whose bleaching treatment had been carried out in a specialist endodontic practice. The sample comprised 204 teeth with a review period of between 1 and 19 years. One-hundred-and-fifty-one teeth (77.94 per cent) had an associated history of traumatic injury. All teeth had been treated with a combination of thermocatalytic and 'walking bleach' procedures using 30 per cent hydrogen peroxide. In 54.41 per cent of teeth, gutta-percha and AH26 root-fillings were kept at the height of the cemento-enamel junction while 18.63 per cent were below and 26.96 per cent were above the CEJ. Sealing cement was not placed over the gutta-percha and AH26 root-fillings in any of the teeth in the study. It was found that a total of four teeth from the sample group (1.96 per cent) had developed invasive cervical resorption during the review period. All of these teeth had a history of traumatic injury and the level of gutta-percha was at the CEJ.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasive cervical resorption: an analysis of potential predisposing factors.

OBJECTIVE: An investigation was undertaken to assess potential predisposing factors to invasive cervical resorption. METHOD AND MATERIALS: A group of 222 patients with a total of 257 teeth displaying varying degrees of invasive cervical resorption were analyzed. Potential predisposing factors, including trauma, intracoronal bleaching, surgery, orthodontics, periodontal root scaling or planing, bruxism, delayed eruption, developmental defects, and restorations were assessed from the patients' history and oral examination. RESULTS: Of the potential predisposing factors identified, orthodontics was the most common sole factor, constituting 21.2% of patients and 24.1% of teeth examined. Other factors were present in an additional 5.0% of orthodontically treated patients (4.3% of teeth), and these consisted principally of trauma and/or intracoronal bleaching. Trauma was the second most frequent sole factor (14.0% of patients and 15.1% of teeth). Trauma in combination with intracoronal bleaching, orthodontics, or delayed eruption constituted an additional 11.2% of patients (10.6% of teeth). Intracoronal bleaching was found to be the sole potential predisposing factor in 4.5% of patients and 3.9% of teeth, and an additional 10.4% of patients and 9.7% of teeth showed a combination of intracoronal bleaching with trauma and/or orthodontics. Surgery, particularly involving the cementoenamel junction area, was a sole potential predisposing factor in 6.3% of patients and 5.4% of teeth. Periodontal therapy, including deep root scaling and planing, showed a low incidence, as did other factors, such as bruxism and developmental defects. The presence of an intracoronal restoration was the only identifiable factor in 15.3% of patients and 14.4% of teeth, while 15.0% of patients and 16.4% of teeth showed no identifiable potential pedisposing factors. CONCLUSION: These results indicated a strong association between invasive cervical resorption and orthodontic treatment, trauma, and intracoronal bleaching, either alone or in combination.

Treatment of invasive cervical resorption: an analysis of results using topical application of trichloracetic acid, curettage, and restoration.

OBJECTIVE: The purpose of this study was to carry out a clinical evaluation of the treatment of invasive cervical resorption. METHOD AND MATERIALS: Topical application of a 90% aqueous solution of trichloracetic acid, curettage, nonsurgical root canal treatment where necessary, and restoration with glass-ionomer cement were performed on 94 patients with a total of 101 affected teeth. A minimum of 3 years' follow-up was required, unless failure occurred before that time, in which case that treatment was included. Teeth were divided into four classes, depending on the extent of the resorptive process. Class 1 represented the least invasive resorptive lesion, near the cervical area with shallow penetration into dentin, while class 4 represented the most invasive resorptive process, which had extended beyond the coronal third of the root. RESULTS: In all class 1 and class 2 cases, the results showed complete success, judged by an absence of resorption or signs of periapical or periodontal pathosis. When overall success was judged by absence of resorption and periapical or periradicular pathosis, the success rate in class 3 lesions was 77.8%. Only 12.5% of teeth in class 4 were free of resorption and deemed to be clinically sound. CONCLUSION: The treatment regimen was successful in class 1 and class 2 cases, reasonably successful in class 3 cases, and generally unsuccessful in class 4 resorptions, where alternative treatment is recommended. Diagnosis of lesions at an early stage is, therefore, highly desirable.

Clinical, radiologic, and histopathologic features of invasive cervical resorption.

Invasive cervical resorption is a relatively uncommon form of external root resorption. There may be no external signs, and the resorptive condition is often detected by routine radiographic examination. Where the lesion is visible, the clinical features vary from a small defect at the gingival margin to a pink coronal discoloration of the tooth crown resulting in ultimate cavitation of the overlying enamel. The condition is usually painless unless pulpal or periodontal infection supervenes. Radiographic features of lesions vary from well-delineated to irregularly bordered mottled radiolucencies, and these can be confused with dental caries. A characteristic radiopaque line generally separates the image of the lesion from that of the root canal, because the pulp remains protected by a thin layer of predentin until late in the process. Histopathologically, the lesions contain fibrovascular tissue with resorbing classic cells adjacent to the dentin surface. More advanced lesions display fibro-osseous characteristics with deposition of ectopic bonelike calcifications both within the resorbing tissue and directly on the dentin surface. Secondary invasion of microorganisms into the pulp or periodontal ligament space will elicit a normal inflammatory response.

Tooth discoloration and resolution following a luxation injury: significance of blood pigment in dentin to laser Doppler flowmetry readings.

Discoloration of teeth is common sequel of dental trauma and is often taken as a sign of irreversible pulpal degeneration, particularly if the crown becomes gray or blue-gray in appearance. If a viable blood supply remains or revascularization occurs following trauma to teeth, removal of blood pigments by normal biologic processes can occur. The assessment of blood flow with laser Doppler flowmetry is an additional diagnostic aid following dental injuries. This technology has been used to monitor the clinical progress of two central incisors that had been palatally luxated in a sporting accident. Color changes were observed and were correlated with symptomatic and radiographic evaluation, sensibility tests, and laser Doppler readings. The results of these examinations indicated that the blood pigment within a discolored tooth crown interfered with laser light transmission. The limitation of this new technology in the assessment of teeth discolored following trauma is significant. Visual radiographic and symptomatic assessment remain as the principal diagnostic criteria at the present time.

Invasive cervical resorption following trauma.

Invasive cervical resorption is an insidious and often aggressively destructive form of external root resorption which may occur as a late complication following dental trauma particularly where it involves damage to cementum and supporting tissues. While this resorption may be evident clinically as a pink coronal discolouration, later with cavitation of the enamel, often there are no obvious external signs and the condition is only detected radiographically. It is characterised by the invasion of the cervical region of the root by fibrovascular tissue which progressively resorbs dentine, enamel and cementum. The dental pulp remains protected by an intact layer of dentine and predentine until late in the process. Ectopic calcifications can be observed in advanced lesions both within the invading fibrous tissue and deposited directly onto the resorbed dentine surface. The aetiology of invasive cervical resorption is unknown but trauma has been documented as a potential predisposing factor. A recent study by the author of 222 patients with a total of 257 teeth which displayed varying degrees of invasive cervical resorption showed that trauma alone was a potential predisposing sole factor in 14% of patients and 15.1% of teeth. Trauma in combination with bleaching, orthodontics or delayed eruption was found in an additional 11.2% of patients or 10.6% of teeth and of these a combination of trauma and bleaching occurred in a relatively high proportion of 7.7% of patients or 7.4% of teeth. This study also revealed that of other potential predisposing factors orthodontics was the most common sole factor constituting 21.2% of patients and 24.1% of teeth examined. Successful treatment of invasive cervical resorption is dependent on the extent of the resorptive process. Teeth with invasive cervical resorption have been divided into four classes. Whilst several treatment modalities are possible, a clinical evaluation of the treatment of this condition by the topical application of a 90% aqueous solution of trichloracetic acid, curettage, endodontic therapy where necessary and restoration with a glass ionomer cement has been evaluated on 94 patients with a total of 101 teeth with a minimum follow-up period of three years. Results indicate a satisfactory treatment outcome can be anticipated in Class 1, 2 and 3 cases. In Class 4 resorption no treatment or alternative therapy is recommended. Diagnosis of lesions at an early stage of development is highly desirable and therefore the patients who have a potential for the development of this condition by virtue of a history such as trauma should be monitored radiographically at intervals throughout life.

Avoiding "the space" by the treatment of compromised teeth.

The advent of implant therapy has given new a dimension to dentistry particularly where teeth have been irretrievably damaged or pathologically involved. There are many situations however, where endodontic or combined therapy may effectively retain compromised teeth and clinicians should carefully evaluate evidence-based treatment. The main areas discussed are: transverse and crown root fractures and invasive cervical resorption. Transverse root fractures have an excellent natural healing capacity and will also respond favourably to treatment if pulp necrosis occurs in the coronal segment. Studies have shown that crown root fractures can be effectively treated by combined endodontic-orthodontic-periodontic and prosthodontic therapy. Invasive cervical resorption has been classified into four classes depending on the degree of infiltration of resorptive tissue into the tooth structure. A study of treatment results following the topical application of 90% aqueous trichloracetic acid, curettage and restoration indicated that this regimen could be successfully applied to Classes 1, 2 and 3 resorption.

External root resorption.

Root resorption is a pathological process initiated by specific clastic cells which remove the organic and mineral components of dental hard tissues. Clastic cell activity in teeth is associated with a number of factors which include biomechanical forces, mechanical, surgical and chemical trauma, endodontic micro-oragnisms and their toxins, developmental defects, neoplasia, and hormonal disturbances. The therapeutic measures which can regulate clastic activity include endodontic treatment, the use of specific anticlastic agents such as Ledermix paste, non-specific necrobiotic agents such as calcium hydroxide and trichloracetic acid, surgery or root surface conditioners. Accurate diagnosis is essential to the correct application of therapy. While some resorptions are self-limiting, others such as inflammatory root resorption require active and prompt endodontic preparation and medication to allow the control of clastic activity. One treatment regimen of invasive cervical and related conditions involves careful and accurate application of a chemical cauterizing agent, trichloracetic acid, followed by curettage and restoration.