Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study

Abstract

Background: This study was done to assess the prevalence of Dentine hypersensitivity (DH) and its associated risk factors. Materials & Methods: This epidemiological study was done among patients coming to dental college regarding prevalence of DH. A self structured questionnaire along with clinical examination was done for assessment. Descriptive statistics were obtained and frequency distribution was calculated using Chi square test at p value <0.05. Stepwise multiple linear regression was also done to access frequency of DH with different factors. Results: The study population was comprised of 655 participants with different age groups. Our study showed prevalence as 55% and it was more common among males. Similarly smokers and those who use hard tooth brush had more cases of DH. Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush. Most aggravating factors were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing. Conclusion: A high level of dental hypersensitivity has been in this study and more common among males. A linear finding was shown with age, smoking and type of tooth brush. How to cite this article: Vijaya V, Sanjay V, Varghese RK, Ravuri R, Agarwal A. Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study. J Int Oral Health 2013;5(6):88-92 .

Introduction

Dentine hypersensitivity (DH) may be defined as a transient pain arising from exposed dentine, typically in response to chemical, thermal, tactile or osmotic stimuli, which cannot be explained by any other dental defect or pathology. 1 , 2

It is commonly encountered, with prevalence as 74%. 3 It is a relatively common dental clinical condition in permanent teeth as a consequence of loss of enamel and/or cementum. Patients usually do not report this painful condition to their dental practitioners and when they do, they report experiencing sharp pain after a number of stimuli. 4 It has been shown that the etiology of DH is multi-factorial, however interactions between several factors including stimuli as well as predisposing factors may play an important role in initiating this condition. 5 Cold and air stimulation are known to be the commonest stimuli while dietary acid is also shown to have a significant potential in evoking DH. 6 Among the predisposing factors for DH, gingival recession and abrasion, as well as erosion and attrition have been considered as important ones. 2

Several theories have been proposed to explain the mechanism of dentine sensitivity and, therefore, of DH. 7 The accepted theory about this is “Hydrodynamic theory”. It suggests that a quick shift of fluids occur within the dentinal tubules after stimulus application. It leads to the activation of inner dentine and the pulp and therefore pain initiates. 8

Incidence of DH increases with advancing age 9 and it was reported it as 25% to 40%. 10 So knowing the variability of the disease and its multifactorial risk factors, this survey is being conducted to know the prevalence of dental hypersensitivity.

Materials and Methods

This epidemiological study was conducted among patients coming to Multi centre study in Bilaspur, Chattisgarh, India during May to June 2013.

Study population: After obtaining ethical permission from the Institute, survey was started and a sample of 655 was finalized including 360 males and 295 were females. Those who were having permanent teeth were taken into study, patients with fractured and carious teeth were excluded. A written informed consent was obtained from all the participants.

Examination: To diagnose the cases of dentine hypersensitivity, examination was done clinically and on the basis of patient’s response. First of all teeth were dried with compressed air and questions were asked regarding sensitivity of teeth. If patient gave positive response then a conformity test was done using a blast of air from a syringe of dental unit. In cases the response was doubtful, and then a cotton piece impregnated with cold water was used to confirm the definitive diagnosis of DH. A pretested self-administered questionnaire was used to gain

1. Predictors: (Constant), age

2. Predictors: (Constant), age, smoking

3. Predictors: (Constant), age, smoking, type of tooth brush

information regarding demographic variables, smoking habits, type of tooth brush, self-reported DH and the activating factors.

Data analysis

SPSS version 16.0 (SPSS, Chicago, IL, USA) was used for data analysis. Chi square test was used to find the significance of difference of dentine hypersensitivity at p value <0.05. Step-wise multiple linear regression analysis was used to assess the independent variables that significantly influenced the variance in the dependant variables (Dentin hypersensitivity).

Results

The study population was compromised of 655 participants and they were divided according to age groups as 297(45.3%) were from 18 to 27 years of age; 198(30.2%) between 28 to 37 years and 160 (24.4%) were above 38 years.

In the present study, around 55% of the participants were having dentine hypersensitivity which was more among males (30.1%) as there counter parts (24.9%) (Table 1).

Table 1: Showing Dentin hypersensitivity according to gender

Gender	Dentin hypersensitivity		p-value
	No	%	0.892**
Male	197	30.1%
Female	163	24.9%

A significant high frequency of dentine hypers-ensitivity was found among smokers (39.7%) than those who do not smoke (21.4%) as shown in Table 2.

Table 2: Showing Dentin hypersensitivity according to habit of smoking

Gender	Dentin hypersensitivity		p-value
	No	%	0.000*
Smokers	100	15.3%
Non smokers	260	39.7%

When compared according to age wise, significant results were obtained with highest prevalence (20.4%) in 18 to 27 year age group followed by ≥38 year’s age group (19.5%) and 28-37 years (15.1%) (p=0.000) as illustrated in Table 3.

Table 3: Showing Dentin hypersensitivity according to different age groups

Age	Dentin hypersensitivity		p-value
	No	%	0.000*
18-27 years	133	20.3%
28-37 years	99	15.1%
≥38 years	128	19.5%

Table 4 showed results according to the type of tooth brush and low rate of participants were having dentine hypersensitivity with soft tooth brush (13.8%) where as more among those who use hard tooth brush (21.4%). Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush (Table 5).

Table 4: Showing Dentin hypersensitivity according to usage of different tooth brushes

Tooth brush	Dentin hypersensitivity		p-value
	No	%	0.000*
Soft	90	13.7%
Medium	130	19.8%
Hard	140	21.4%

Table 5: Stepwise multiple linear regression showing Dentin hypersensitivity according to different independent variables

Model	R	R square	F value	Sig.
1	0.267(a)	0.071	50.024	0.000
2	0.349(b)	0.119	45.120	0.000
3	0.439(c)	0.189	51.709	0.000

According to the site of occurrence, upper posterior teeth were most affected (30.1%) and upper anterior teeth were least affected (25%) ( Graph 1 ).

Graph 1: Frequency of Dentin hypersensitivity at different sites.

Graph 2 showed different factors that activate DH and the most common were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing.

Graph 2: Different factors associated with dentine hypersensitivity.

Discussion

Dentinal hypersensitivity is difficult condition for patients to explain and also for dentists to precisely diagnose. The results of the present questionnaire and examination showed prevalence of DH as 55% which is very high. Where as Chrysanthakopoulos found it as 18.2% among dental patients in Greece. 11

But studies in Hong Kong found it as 67.7% in a clinic population, 12 and 68.4 % in Nigerian population. 13 This prevalence was different among other studies conducted in dental practices and it varies from 2.8% to 57.2%. 14 , 15 It could be due to various factors like drinking, consuming sweets, habit of brushing and smoking. Some of these studies have used questionnaires only without any clinical examinations. Where as some studies showed lower results of dentine hypersensitivity as 25% in Brazil population 16 and 32 .58% in Shanghai population. 15

DH was more among male population as compared to female and comparable results were seen in study done by Bamise et al in 2007. 17 However many studies found that females were having more prevalence of DH. 9 , 18 , 19 It has been attributed to the fact that women have better overall healthcare and oral hygiene practices, which would make them more sensitive to DH.

It was also found that DH varies according to age which is also seen in many studies. 20 , 21

The present study showed more frequency of DH among 18 to 27 years age group which was comparable to Gillam et al in 2002. 22 But some studies had shown in 30-39 years old age group9,10 and some in among 50-59 years old. 21

Most frequently involved teeth were upper and lower posteriors where as Taani and Awartani in 2002 23 and Rees et al in 2003 found in lower anterior and upper posteriors. 12

Factors that activate DH was mostly cold water and sweet foods in this study and findings are in agreement with many studies. 19 , 17

However study by Chun-hung found that DH is due to fruit juices as they contain citrus fruits. 24

According to the type of tooth brush; most cases of DH were seen among participants who use hard brush. As we know that hard filaments of tooth brush causes abrasion of teeth which leads to hypersensitivity.

Conclusion

The study revealed high prevalence rate of DH as 55% and it varies according to different age groups and more among males. It is mostly associated with age of the patients, smoking habit and type of tooth brush. So screening for dentine hypersensitivity at community level is required for early treatment.