Association Between Cervical Abrasion, Oral Hygiene Practices and Buccolingual Dimension of Tooth Surfaces: A Cross-Sectional Study.

Background: Cervical abrasion is a multifactorial process due to the use of abrasive dentifrices along with improper brushing patterns. An extensive lesion may cause loss of structural integrity of tooth and esthetically unacceptable. The purpose of the study was to assess the prevalence of cervical abrasion with age, gender, and oral hygiene practices among workers in a spinning mill, Kerala. The study also aimed to identify the buccolingual measurements of each abraded tooth using the Community Abrasion Index of Treatment Needs (CAITN) probe. Materials and
Methods: A cross-sectional study where 366 subjects (257 males and 109 females) above 20 years of age were selected using a random sampling technique. Data was collected from the assessment form comprising demographic data and oral hygiene practices of the subjects. Clinical examination for abrasion and buccolingual measurements of abraded tooth recorded using CAITN probe. The statistical analysis was done using SPSS 26.0. for calculating descriptive statistics, Chi-square test, and binary logistic regression.
Results: The overall prevalence of abrasion was 37.2% and 97.7% of subjects with abrasion had sensitive teeth and were statistically significant. Age, gender (males) and combined horizontal and vertical method of brushing technique were strongly associated with the cervical lesion (P < 0.001). Binary logistic regression analysis showed that age group, gender, combined horizontal and vertical method of brushing, and presence of sensitive tooth was associated with the abrasion.
Conclusion: It is concluded that the severity of the abrasion is an age-related phenomenon associated with combined horizontal and vertical strokes of brushing and is common among the male population. Dentinal hypersensitivity is also more prevalent with cervical abrasion. The novel CAITN probe can be used as an effective tool to assess the cervical abrasion and its treatment needs. Copyright:

INTRODUCTION

Cervical abrasion is defined as the loss of tooth structure in noncarious lesions at the cementoenamel junction (CEJ). Abrasion is considered as a multifactorial process of which the most common cause is the use of abrasive dentifrices along with improper use of horizontal toothbrushing patterns. It is estimated that 25% of the tooth surface loss occurs due to a noncarious process. An extensive lesion may cause structural loss of tooth integrity and esthetically unacceptable.[12] The tooth hypersensitivity can occur owing to abrasion exposing the underlying dentin or root surface.[3]

Toothbrushing characteristics such as frequent or vigorous tooth brushing, faulty or incorrect techniques, type of the tooth brush bristles, hand dexterity, or abrasive dentifrices have been linked to the cervical lesions but with conflicting results.[45] Moreover, individual variations such as tooth anatomy, periodontal status, or phenotype may play a role in modifying the severity of the lesion.[6] Abrasion due to toothbrush is one of the major factors related with the progression of noncarious cervical lesions (NCCL).[17]

Loss of tooth structure due to factors unrelated to dental caries such as cervical abrasion is referred to as NCCL.[8] Generally, cervical abrasion is seen as wedged-shaped or grooved lesions at CEJ.[4] The risk factors associated with the oral diseases involve a wide range of environmental, genetic, socio-behavioural factors, oral hygiene practices, and affordability to dental treatment. Henceforth, determining the risk factors involved is crucial in order to take preventative steps.[89]

The aim of the study is to evaluate the prevalence of cervical abrasion and investigate its relationship with age, gender, and oral hygiene practices. Further, this study was conducted as a part of a comprehensive study to determine the depth of the cervical abrasion using the CAITN probe obtained from the difference between the normative buccolingual diameter of the sound tooth and that of the abraded tooth.

MATERIALS AND METHODS

The study was approved by the institutional ethical committee and written informed consent was obtained from all the participants. This cross-sectional study was conducted among 366 adults above 20 years of age, employed in a spinning mill located at Thrissur district, Kerala to assess the abrasive lesions of teeth. The diagnostic criteria for cervical abrasion were the presence of non-carious wedge-shaped lesions with sharp edges, or C-shaped lesions with rounded edges in the cervical third of the tooth. A random sampling technique was used and the sample size was estimated using the formula: n = z2 (pq)/e2 where e = 5%, Z = 1.96 (at 95% confidence) P = 39.2%, q = 60.8%, n = 366. Edentulous individuals, subjects undergoing orthodontic treatment, smokers/tobacco chewers are excluded from the study.

Data collection and clinical examination were performed by one investigator, pretrained to diagnose the lesion. The intra-examiner agreement was assessed by randomly reexamining 20 study subjects at an interval of 14 days. Consistency was determined by the kappa index of 0.83 indicating a substantial agreement. The data assessment form comprises general information on oral hygiene practices such as type of cleaning aids, materials, and methods used in cleaning, time and frequency of brushing, frequency of changing the toothbrush, use of other cleaning aids, and presence of sensitive tooth. Clinical examination of all natural teeth excluding third molars for cervical abrasion was recorded and buccolingual measurements of the abraded tooth were measured using the CAITN probe, a newly developed instrument to measure cervical abrasion more quantitatively. The beak of the instrument is engaged either in buccopalatal or buccolingual direction and locked to record the measurement.

Descriptive statistics were determined for all variables and the Chi-square test was applied to evaluate the association between gender, oral hygiene habits, and cervical abrasion. An independent sample t-test was applied to compare differences in mean age and abrasion and also mean buccolingual measurement of abraded teeth with sensitivity. Binary logistic regression analysis was performed to assess the odds ratio (OR) of associated factors that predicts abrasion. A P < 0.05 was considered significant. SPSS 26.0 (IBM SPSS Statistics for Windows, Version 26.0. South Asia- Bangalore: IBM Corp) was used for statistical analysis.

RESULTS

A total of 366 subjects above 20 years of age comprising of 257 males and 109 females were examined. The mean age was 45.14 ± 14.46 years for males and 48.14 ± 13.45 years for females. The overall mean age of the study sample was 46.03 ± 14.22 years. Table 1 shows that the prevalence of abrasion was 37.2% with mean age of 52.66 ± 7.43. The abrasive lesions increase with age and were statistically significant (P < 0.001). The prevalence of abrasion among males and females were represented in Table 2 and found to be 42.8% and 23.9% respectively with statistically significant difference (P = 0.001). The association between the cervical abrasion and oral hygiene practices was determined by applying Chi-square test. There were statistically significant difference among the type of brushing technique, presence of sensitive tooth and abrasion [Table 2].

Table 1

Independent t-test to compare mean age

Cervical abrasion	n (%)	Mean±SD	P
Age
Absent	230 (62.8)	42.11±15.75	<0.001**
Present	136 (37.2)	52.66±7.43

** Highly significant. SD: Standard deviation

Table 2

Comparison of age, gender, oral hygiene practices and cervical abrasion

	Cervical abrasion			P
	Absent, n (%)	Present, n (%)	Total, n (%)
Gender
Male	147 (57.2)	110 (42.8)	257 (100.0)	0.001**
Female	83 (76.1)	26 (23.9)	109 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Type of cleaning aid
Soft tooth brush	52 (61.9)	32 (38.1)	84 (100.0)	0.152
Medium tooth brush	81 (69.8)	35 (30.2)	116 (100.0)
Hard tooth brush	90 (57.3)	67 (42.7)	157 (100.0)
Finger	7 (77.8)	2 (22.2)	9 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Method of cleaning
Horizontal	163 (71.8)	64 (28.2)	227 (100.0)	<0.001**
Vertical	16 (51.6)	15 (48.4)	31 (100.0)
Horizontal and vertical	51 (47.2)	57 (52.8)	108 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Materials used
Fluoride tooth paste	196 (62.4)	118 (37.6)	314 (100.0)	0.525
Non fluoride tooth paste	15 (60.0)	10 (40.0)	25 (100.0)
Medicated tooth paste	10 (83.3)	2 (16.7)	12 (100.0)
Others	9 (60.0)	6 (40.0)	15 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Frequency of cleaning
Once daily	127 (61.1)	81 (38.9)	208 (100.0)	0.418
Twice/thrice daily	103 (65.2)	55 (34.8)	158 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Time of brushing
Before breakfast	127 (61.1)	81 (38.9)	208 (100.0)	0.418
Before breakfast and after dinner	103 (65.2)	55 (34.8)	158 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Frequency of changing toothbrush (months)
1	27 (62.8)	16 (37.2)	43 (100.0)	0.976
2	53 (61.6)	33 (38.4)	86 (100.0)
3	64 (64.6)	35 (35.4)	99 (100.0)
>3	86 (62.3)	52 (37.7)	138 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Use of other oral hygiene aid
No	220 (63.6)	126 (36.4)	346 (100.0)	0.222
Yes	10 (50.0)	10 (50.0)	20 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)
Sensitive tooth
Absent	229 (70.9)	94 (29.1)	323 (100.0)	<0.001**
Present	1 (2.3)	42 (97.7)	43 (100.0)
Total	230 (62.8)	136 (37.2)	366 (100.0)

**Highly significant

In the comparison of the type of toothbrush bristles among subjects with abrasion, 38.1% used soft bristles, 30.2% used medium bristles while 42.7% used hard bristles, and 22.2% of subjects were found to be using a finger. Fifty percent of subjects were using other abrasive materials such as brick/tooth powder, charcoal, etc. as a cleansing aid. The difference was statistically significant (P < 0.001) among subjects using horizontal (28.2%), vertical (48.4%), and combined method (52.8%) of brushing in the abraded teeth [Table 2].

Table 3 shows the descriptive statistics of abrasion and hypersensitivity of each tooth. Cervical abrasion was more prevalent in the left first molar (19.1%) followed by left first premolar (16.7%) in the maxillary arch and mandibular first (16.7%) and second (13.1%) premolars on the left side. The mean buccolingual measurements of abraded teeth were higher in maxillary right second molar (10.33 mm) and mandibular left first and second molar (10 mm). 97.7% of subjects with abrasion had sensitive teeth [Table 2] and were statistically significant (P < 0.001) of which 50% reported sensitivity in their left second molar followed by 40% in left lateral incisor and 26.2% in left first premolar in the maxillary arch. While in the mandibular arch, the left central incisor (33.3%) and left the first molar (28.6%) were found to be highly sensitive. The mean buccolingual measurements of abraded sensitive teeth were higher in mandibular left first molar (10 mm) and maxillary left first molar (9.76 mm) [Table 3].

Table 3

Descriptive statistics of buccolingual measurement of cervical abrasion and sensitivity of each tooth

	Tooth	n	Prevalence of cervical abrasion		Sensitivity among cervical abrasion
			n(%)	Buccolingual measurements, mean±SD	n(%)	Buccolingual measurements, mean±SD
Maxillary arch
Central incisor	Right	366	6 (1.6)	5.00±0.000	0
	Left	366	4 (1.1)	4.67±1.033	1 (25.0)	5.00
Lateral incisor	Right	366	11 (3.0)	5.20±0.447	3 (27.3)	5.50±0.707
	Left	366	5 (1.4)	4.27±0.786	2 (40.0)	4.00±1.000
Canine	Right	366	20 (5.5)	5.17±0.408	3 (15)	6.00
	Left	366	6 (1.6)	4.95±0.945	1 (16.7)	5.00±1.000
First premolar	Right	366	46 (12.6)	6.34±1.124	7 (15.2)	5.81±1.047
	Left	366	61 (16.7)	6.28±0.958	16 (26.2)	5.86±0.900
Second premolar	Right	366	42 (11.5)	6.33±1.028	8 (19.0)	6.15±0.801
	Left	366	54 (14.8)	6.31±1.199	13 (24.1)	5.50±0.756
First molar	Right	366	44 (12.0)	9.97±0.564	6 (13.6)	9.76±1.091
	Left	366	70 (19.1)	10.14±0.409	17 (24.3)	10.17±0.408
Second molar	Right	366	3 (0.8)	9.50±2.345	0
	Left	366	6 (1.6)	10.33±0.577	3 (50.0)	9.00±3.606
Mandibular arch
Central incisor	Right	366	5 (1.4)	4.67±0.816	1 (20.0)	5.00
	Left	366	6 (1.6)	4.20±0.837	2 (33.3)	5.00
Lateral incisor	Right	366	4 (1.1)	4.75±0.957	0 (0.0)
	Left	366	4 (1.1)	4.00±0.816	1 (25.0)	5.00
Canine	Right	366	7 (1.9)	4.75±1.035	1 (14.3)	4.00
	Left	366	8 (2.2)	4.00±0.816	1 (12.5)	4.00
First premolar	Right	366	35 (9.6)	5.98±0.885	5 (14.3)	5.60±0.910
	Left	366	61 (16.7)	6.11±0.676	15 (24.6)	6.00±0.707
Second premolar	Right	366	26 (7.1)	6.19±0.915	4 (15.4)	6.10±1.595
	Left	366	48 (13.1)	6.04±0.662	10 (20.8)	6.00±0.816
First molar	Right	366	16 (4.4)	10.00±0.00	2 (12.5)	10.00±0.000
	Left	366	21 (5.7)	9.31±1.702	6 (28.6)	10.00±0.000
Second molar	Right	366	0
	Left	366	1 (0.3)	10.00	0

SD: Standard deviation

Table 4 shows the comparison of mean buccolingual measurements and sensitivity of abraded teeth of maxillary and mandibular arch. The results of independent t-test reported statistically significant difference in buccolingual measurements and sensitivity only in right maxillary first premolar and left maxillary second premolar. The results of the binary logistic regression model to predict the risk factors associated with cervical abrasion are summarized in Table 5. It showed that age group (OR = 1.07), gender (males with OR = 3.80), combined horizontal and vertical method of brushing (OR = 2.20), and presence of sensitive tooth (OR = 101.2) were associated with the presence of cervical abrasion at 95% confidence interval.

Table 4

Independent t-test to compare mean buccolingual measurements of cervical abrasion and sensitivity

Tooth	Sensitivity	Maxillary arch (left side)			Maxillary arch (right side)
		n	Mean±SD	P	n	Mean±SD	P
Central incisor	Absent	3	5±0.000	-	6	4.67±1.033	-
	Present	1	5±-	0	-
Lateral incisor	Absent	3	5±0.000	0.5	8	4.38±0.744	0.510
	Present	2	5.5±0.707	3	4±1
Canine	Absent	5	5±0.000	-	17	4.94±0.966	0.924
	Present	1	6±-	3	5±1
First premolar	Absent	45	6.53±1.100	0.026**	39	6.36±0.959	0.206
	Present	16	5.81±1.047	7	5.86±0.9
Second premolar	Absent	41	6.39±1.093	0.475	34	6.5±1.212	0.032**
	Present	13	6.15±0.801	8	5.5±0.756
First molar	Absent	53	10.04±0.192	0.320	38	10.13±0.414	0.848
	Present	17	9.76±1.091	6	10.17±0.408
Second molar	Absent	3	10±0.000	0.678	3	10.33±0.577	-
	Present	3	9±3.606	0
Tooth	Sensitivity	Mandibular arch (left side)			Mandibular arch (right side)			Mandibular arch (right side)
		n	Mean±SD	P	n	Mean±SD	P
Central incisor	Absent	5	4.60±0.894	-	4	4±0.816	0.353
	Present	1	5±-		1	5±-
Lateral incisor	Absent	3	4.67±1.155	-	4	4±0.816
	Present	1	5±-		0	-±-
Canine	Absent	7	4.86±1.069	-	6	4±0.894	0.999
	Present	1	4±-		1	4±-
First premolar	Absent	46	6.11±0.849	0.052	30	6.13±0.681	0.689
	Present	15	5.60±0.910		5	6±0.707
Second premolar	Absent	38	6.21±0.664	0.738	22	6.05±0.653	0.903
	Present	10	6.10±1.595		4	6±0.816
First molar	Absent	15	10±0.000	-	14	9.21±1.805	0.560
	Present	6	10±0.000		2	10±0.000
Second molar	Absent	1	10±-	-	0	-	-
	Present	0	-		0	-

**Highly significant. SD: Standard deviation

Table 5

Binary logistic regression to identify the risk factors for cervical abrasion

Factors	COR	95% CI		P	AOR	95% CI		P
		LL	UL			LL	UL
Age	1.066	1.045	1.087	<0.001**	1.073	1.048	1.099	<0.001**
Gender
Female	1.000				1.000
Male	2.389	1.442	3.958	0.001**	3.799	1.980	7.289	<0.001**
Type of cleaning aid
Finger	1.000
Soft tooth brush	2.154	0.421	11.015	0.357	-
Medium tooth brush	1.512	0.299	7.647	0.617	-
Hard tooth brush	2.606	0.524	12.944	0.242	-
Method of cleaning
Horizontal	1.000				1.000
Vertical	2.688	1.115	5.713	0.025**	2.495	0.966	6.447	0.059
Horizontal and vertical	2.847	1.769	4.581	<0.001**	2.204	1.237	3.927	0.007**
Sensitive tooth
Absent	1.000				1.000
Present	102.3	13.88	754.2	<0.001**	101.2	13.12	780.7	<0.001**

**Highly significant. CI: Confidence interval, OR: Odds ratio, COR: Crude OR, AOR: Adjusted OR, LL: Lower Limit, UL: Upper Limit

DISCUSSION

This study sought to determine the prevalence of cervical abrasion and evaluate its association with the subject traits and oral hygiene practices. The prevalence of abrasions reported in the present study was concurrent with that of Bergstrom and Lavstedt where the prevalence was 31%.[10] However, it is higher than that reported by David K (6.1%), Sud (13%), and lower than Saxena (68.6%) and Borcic (60%–70%).[2111213] Cervical abrasions were more common with maxillary posterior teeth and premolars stems from the fact that the posterior teeth are subjected to stronger occlusal and lateral forces, which is consistent with earlier investigations.[1415]

The findings of this study were similar to those of other studies that found that the prevalence of abrasion upsurges with age.[11121617] This can be attributed to the cumulative influence on tooth resulting in greater intensity of structural tooth loss. Prevalence of abrasion observed among males in the study by Deshpande in the adult population of Nagpur accounts for 45% and the present study shows analogous findings.[18] In this study, males around 45 years of age had a much higher rate of cervical abrasion than females of 48 years of age which were concurrent with similar studies of Hedge and Shetty and Shreshta et al.[216] It could be because males have a considerable muscle mass and strength, which contributes to significant masticatory forces. Also, females are more conscious about their oral health and are more likely to have frequent dental screening and take therapeutic measures. The data from the dentine sensitivity of our study also discloses a parallel agreement with that of Bartlett et al. which reported 58% of study subjects has dentine hypersensitivity.[19]

The current findings also support a link between poor tooth brushing, coarse cleaning materials, and abrasion at the population level.[11013] The combined horizontal and vertical mode of brushing approach had the highest prevalence of cervical lesions. Although statistically insignificant, this is true for both persons who brush with hard bristles and those who brush with indigenous materials. According to the earlier research studies, lesions are more common in all age groups among people who brush their teeth horizontally and with abrasive materials.[2] Abrasive lesions show statistically significant differences with increasing frequency and time of brushing, frequency of changing toothbrushes, and type of toothpaste used. Similar observations were reported in the literature.[13]

The independent variables considered as risk factors of abrasion are brushing technique, time and frequency of brushing, frequency of changing toothbrush, stiffness of the bristles and type of the toothpaste, and abrasives used. Of these variables, the association was stronger only with combined horizontal and vertical brushing technique and abrasive dentifrice. Abrasion and eventual hypersensitivity are almost often caused by improper brushing technique.[20] The current study reinforces the findings of prior studies,[121] which show that horizontal brushing is the most dangerous and prone to cause abrasion of any technique. In the present study, most of the subjects employed horizontal brushing technique previously which then was later modified to vertical brushing technique. Henceforth the combined brushing pattern was computed to have significant association with cervical abrasion. In terms of sensitivity, the study found that nearly all of the participants with cervical abrasion were hypersensitive. Hypersensitive cervical abrasion is deemed to be one of the perplexing dental maladies. However, individual tooth-wise analysis of the association between sensitivity and abrasion showed statistical significance only in the maxillary premolars. The reason behind this can be attributed to the fact that the distribution of hypersensitive cervical abrasion was not equally distributed in each tooth category. It was found that the sensitivity was not reported in the second molars and left lateral incisors of the mandibular arch and left central incisor and second molars of the maxillary arch in our study sample. The use of more aboriginal materials is far more detrimental, causing higher abrasiveness in teeth with severe hypersensitivity, especially in later decades of life. Abrasive lesions, on the other hand, did not demonstrate significant statistical differences with the type of toothpaste used and frequency of changing the toothbrush. Radentz et al. did not demonstrate any significant differences between the type of toothbrush bristles which was in concordance with our study.[15] The binary logistic regression analysis revealed that the risk of cervical abrasion remained statistically significant for age, gender, method of brushing, and tooth sensitivity after other confounding factors were taken into consideration.

Few attempts have been made over the years to establish a cervical abrasion index that is appropriate for widespread usage in research and clinical applications.[12] Most indices employ changes in the tooth structure at the CEJ to record the severity of the lesions. However, in most cases, the anatomical variations arising from tooth structure loss are a combination of erosion, abrasion, and attrition and it is hard to determine the component that plays a predominant role.[118] Thus the CAITN probe measures cervical abrasion of the tooth more quantitatively. The measurement reflected on the CAITN probe can be easily read and equated against the standardized buccolingual measurement of that tooth to obtain the depth of cervical abrasion. Henceforth this study is a part of the comprehensive study that attempted to develop a new tool or index and thereby to define the depth of the lesion by computing the difference between the normative buccolingual measurement of the previous study and that of the abraded tooth of the present study.

Limitations of the study

Factors such as the amount of pressure of the toothbrush applied and other biological factors such as saliva, composition and occlusion of the dentition, and socio-behavioral factors were not taken into account. Further research and follow-up may enable the mapping of the link between biological variables and abrasion.

CONCLUSION

Abrasion is a self-inflicted destructive issue that can be avoided by providing adequate health education and inspiration. It is vital to tackle the problem at an early stage in order to avoid it from becoming worse.

Clinical significance

The outcome of the study highlighted that the severity of the abrasion is an age-related phenomenon associated with horizontal and vertical strokes of brushing and is common among the male population. The dentinal hypersensitivity is also found to be more prevalent in abraded teeth. Our concern is to develop an easy index that may be used to assess the progression of abrasion by measuring the depth of the lesion in the abraded teeth with respect to the buccolingual measurement. The novel CAITN probe can be used as an effective tool to measure and assess cervical abrasion and its treatment needs.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.