Changes of periodontal parameters following apical surgery: a prospective clinical study of three incision techniques

AIM: To evaluate periodontal changes following apical surgery, and to relate changes to the type of incision and to the type of restoration present at the gingival margin (GM). METHODOLOGY: Periodontal parameters [probing depth (PD), level of GM and clinical attachment, plaque and bleeding indices] were recorded at baseline and 1 year following apical surgery. The periodontal changes were calculated and assessed with respect to the incision technique (intrasulcular incision, papilla base incision and submarginal incision), as well as to the presence and type of a restoration margin in contact with the gingiva. RESULTS: One hundred and eighty-four teeth could be evaluated. No significant differences between the three incision techniques were found regarding changes in PDs and plaque index over time. However, significant differences between the intrasulcular and submarginal incisions were found for changes in levels of GM and clinical attachment. For example, with the intrasulcular incision, there was a mean recession of 0.42 mm at buccal sites, whereas using the submarginal incision there was a gain of 0.05 mm. No statistically significant influence could be demonstrated for the presence and type of restoration margins, or the smoking habit of the patient. CONCLUSION: The type of incision was found to affect changes significantly in periodontal parameters within an observation period of 1 year following apical surgery, whereas the restoration margin and smoking habit did not prove to have any significant effect.

Evaluation of farm-level parameters derived from animal movements for use in risk-based surveillance programmes of cattle in Switzerland

BACKGROUND: This study focused on the descriptive analysis of cattle movements and farm-level parameters derived from cattle movements, which are considered to be generically suitable for risk-based surveillance systems in Switzerland for diseases where animal movements constitute an important risk pathway. METHODS: A framework was developed to select farms for surveillance based on a risk score summarizing 5 parameters. The proposed framework was validated using data from the bovine viral diarrhoea (BVD) surveillance programme in 2013. RESULTS: A cumulative score was calculated per farm, including the following parameters; the maximum monthly ingoing contact chain (in 2012), the average number of animals per incoming movement, use of mixed alpine pastures and the number of weeks in 2012 a farm had movements registered. The final score for the farm depended on the distribution of the parameters. Different cut offs; 50, 90, 95 and 99%, were explored. The final scores ranged between 0 and 5. Validation of the scores against results from the BVD surveillance programme 2013 gave promising results for setting the cut off for each of the five selected farm level criteria at the 50th percentile. Restricting testing to farms with a score ≥ 2 would have resulted in the same number of detected BVD positive farms as testing all farms, i.e., the outcome of the 2013 surveillance programme could have been reached with a smaller survey. CONCLUSIONS: The seasonality and time dependency of the activity of single farms in the networks requires a careful assessment of the actual time period included to determine farm level criteria. However, selecting farms in the sample for risk-based surveillance can be optimized with the proposed scoring system. The system was validated using data from the BVD eradication program. The proposed method is a promising framework for the selection of farms according to the risk of infection based on animal movements.