A clinical approach strategy for the diagnosis, treatment and evaluation of external cervical resorption.

AIM: To propose a clinical approach strategy on the diagnosis, treatment and evaluation of external cervical tooth resorption (ECR) cases. To investigate and discuss the outcome of this approach. METHODOLOGY: A clinical approach strategy on ECR was developed based on a retrospective observation study of 542 teeth. Forty-seven teeth were excluded due to lack of clinical/radiographical information, and 182 were immediately extracted. This approach had three steps: diagnosis, treatment planning and evaluation. During diagnosis, the medical, dental history and clinical/radiographical characteristics were evaluated. Depending on the resorption extent, ECR cases were categorized into four classes according to Heithersay's classification. During treatment planning, a treatment decision flowchart was prepared based on four main decisive criteria: probing feasibility, pain, location and extent of resorption (class), and existence of bone-like tissue. Three treatment options were applied: (a) extraction, (b) monitoring or (c) conservative treatment by external, internal or combination of internal-external treatments. During evaluation, assessment of ECR progression, tooth survival and other factors like aesthetics and periodontal attachment were performed. Descriptive statistical analysis of the outcome for up to 10 years (for the overall clinical approach and for each individual treatment decision), was carried out with OriginLabs OriginPro 9 and Microsoft Excel 365. RESULTS: A three-step strategy was developed on how to deal with ECR cases. Indicative examples of each treatment decision were presented and discussed. The overall survival rate of this strategy was 84.6% (3 years), 70.3% (5 years), 42.7% (8 years) and 28.6% (10 years). Higher survival rate was observed for external treatment decision than for internal. The success of each treatment decision depended on the extent of the resorption (class). The success of a treatment decision should be based on the long-term outcome, as a different evolution can be observed with time. CONCLUSIONS: A clinical approach strategy was introduced on ECR pathosis. This strategy was not solely based on ECR class, as other important decisive criteria were considered. This step-wise approach, has a 70.3% survival rate with a mean of 5 years. This work will hopefully provide an incentive for a broader collaboration, to potentially establish a universally accepted ECR treatment strategy.

Is Hypoxia Related to External Cervical Resorption? A Case Report.

Despite the fact that external cervical resorption (ECR) is a well-known and rather frequently met condition, the driving force of this phenomenon still remains unclear. Recently, hypoxia has been linked to ECR. Thus, the aim of this work was to investigate the existence of hypoxia in ECR and hypothesize on its role at the time of extraction. This work is a case study of a tooth with ECR. ECR diagnosis was based on clinical and radiographic examination with cone-beam computed tomographic imaging. The extracted tooth was further analyzed by using nanofocus computed tomographic imaging and immunohistology. To investigate the 3-dimensional extent and pattern of ECR, in vivo cone-beam computed tomographic imaging and ex vivo nanofocus computed tomographic imaging were used. Different histologic stains were used to investigate the presence of a hypoxic environment and to gain a better insight into the involved cells, neuronal structures, and remodeling process during ECR. A higher distribution of hypoxia-inducible factor 1a-positive cells was found in the apical part of the resorption area when compared with the coronal area of the resorption. In addition, a similar distribution of hypoxia-inducible factor 1a-positive odontoblasts was observed in the pulp. Three-dimensional analysis of the calcification of the pulp revealed the formation of pulp stones in areas with higher hypoxia. Histology showed that remodeling during ECR can occur according to a layered pattern. This investigation confirms the presence of hypoxia in ECR and shows that there is a gradient of hypoxia within the ECR lesion and surrounding tooth structure. The hypoxic environment within the pulp is also indicated by the formation of pulp stones.