Loss of cementum due to external irritants ELECTRIC PULP TEST OF TEETH WITH PERIODONTAL DISEASE

617 SUMMARY: Purpose: The aim of the research is to investigate the change in pulp vitality of teeth with periodontal disease using electric pulp tester (EPT). Methods: Subjected to observation were 108 patients with chronic periodontitis. Vitality of 805 teeth with periodontal pocket depth greater than 4 mm was studied by EPT. The research was conducted with EPT “Yonovit “. Results: The highest percentage of surveyed teeth (68.4%) respond to the norm when they are tested with EPT – values between 3 μA and 10 μA . Teeth that respond to EPT with values below 3 μA and between 35-100 μA are relatively equal respectively 4.3% and 3.3%. With increased threshold of irritation – 10-35 μA react 23.4% of teeth. Small number of teeth have threshold of irritation over 100 μA 0.6%. Conclusion: The value of EPT among periodontal damaged teeth depends on many factors patient’s age, extent of periodontal affect, group affiliation of teeth, etc.


INTRODUCTION
Anatomic, embryonic and functional relationship exists between the pulp and periodontium.
Since these two structures develop from a common mesodermal source, relationship between pulpal and periodontal diseases can be explained due to their anatomical connection [1,2].
There are different ways of communication between the periodontium and the pulp, which can lead to spread of infection from one of the structures to the other [3,4,5 The main etiological factors are living (bacteria, fungi and viruses) and nonliving pathogens.Some contributing factors such as trauma, perforations, malformations, root resorptions may play an important role [2,3,6].

MATERIALS AND METHODS
The survey included 108 patients with crhonic periodontitis.Pulp reaction of 805 teeth with periodontal pocket greater than than 4mm was tested with EPT.The research was conducted with unit "Yonovit" for EPT.
The following inclusion criteria were considered: patients regardless of gender or race, who had not been submitted to periodontal treatment up to 6 months before the study, and presenting with diagnosis of chronic periodontitis.This diagnosis was based on the following criteria: • Probing depth (PD) -greater than 4mm  In the table below results can be seen in detail: (tab.1)In the table below results can be seen in detail: (tab.2)

Tab. 2. Percentage distribution according to EPT values
As far as it concerns the percentage distribution according to teeth affiliation, the following results were found (the highest percentage in each group): In the group of frontal teeth 71,7 % have PD 4-6 mm and respond normally to EPT -3-10 µA.6,5% of frontal teeth have PD greater than 6 mm and show EPT values between 3-10 µA.In the group of premolars the results are similar -61,8% have PD between 4-6 mm and respond normally to EPT -3-10 µA; 5,8% have PD greater than 6mm and have threshold of irritation 3-10 µA.In the group of molars 36,6% of studied teeth have PD 4-6mm and reaction to EPT 3-10 µA; 11,5% have PD greater than 6 mm and respond with higher threshold of irritation -10-35 µA.
As far as it concerns the percentage distribution according to EPT values, the following results were found (the highest percentage in each group): In the cases with PD 4-6 mm, most of the teeth that respond to EPT with values under 3 µA, between 3-10 µA and 10-35 µA, are frontal -resp.65,5%; 65,2%; 41,9%.Highest percentage of teeth that have EPT values 35-100 µA and over 100 µA are molars -resp.68, 2%; 80%.In the cases with PD greater than 6mm, most of the teeth that respond to EPT with values under 3 µA and between 3-10 µA are frontal teeth -resp.100% and 56,6%.47,4% of teeth that have threshold of irritation 10-35 µA are molars.60% with reaction to EPT between 35-100 µA are premolars.0% of studied teeth with PD greater than 6 mm respond to EPT with values over 100 µA.

DISCUSSION
Several studies have shown the relationship between pulp and periodontium [7,8,9,10].But there are still some controversies on that topic [11,12].Authors such as Mazur and Massler [13] reported that periodontal disease does not influence the pulp.A research of Telma R. Aguiar [8] showed that "radicular pulp of teeth with chronic advanced periodontitis presents characteristics compatible with pulp changes resulting from pulp aging".
According to the study of Seyedmajidi et al. [9], there is a statistically significant correlation between clinical attachment loss and pulp diagnosis (p=0.043).Also there is a statistically significant relationship between clinical attachment loss and calcification in the pulp (p =0.014).[10] The results of our study confirm the statement that there are changes in pulp in relation to periodontal alteration.It is obvious that these changes are as greater and notable as greater is the periodontal disease and probing depth.
According to our study it can be seen that EPT among periodontal damaged teeth depends on many factors -patient's age, extent of periodontal affect, group affiliation of teeth, etc.

CONCLUSION
Lowered and normal values of EPT are registered among the frontal teeth.Raised threshold of irritation can be seen in in the group of molars.Premolars take intermediate position with respect to frontal teeth and molars.
There is a trend toward higher value of EPT with increasing probing depth, distinctively notable in the group of molars (due to more lateral canals).The greater probing depth is, the more notable are the differences between the separate teeth groups.
According to the results from our research, the diagnostic process and the treatment plan of patients with periodontal disease should be considered carefully.