Root Caries Experience and its Association with Risk Indicators among Middle-Aged Adults.

INTRODUCTION: With an increasing number of retained teeth, there is an enhanced susceptibility to periodontal problems with gingival recession, which led root surface exposure to the oral environment and develops the root caries later stages among adults. AIM: Evaluate the root caries experience and its association with risk indicators among middle-aged South Indian adult dental patients using root caries index (RCI; Katz RV - 1979).
MATERIALS AND METHODS: The study was conducted among middle-aged (35 to 44 year) adults in the Outpatient Department of Private Dental Institute. Root caries experience was evaluated using the Katz RCI on a full mouth basis. Statistical analysis was done by using SPSS software.
RESULTS: The prevalence of root caries among study population was 8.9% with a mean RCI score of 1.04 ± 5.10. As age increased mean number of teeth with gingival recession (45.25 ± 27.09), decayed root surfaces (0.34 ± 1.11), filled root surfaces (0.39 ± 2.99), mean number of teeth missing (3.78 ± 6.42), and RCI (1.68 ± 6.93) also increased.
CONCLUSION: Age, gender and higher number of retained teeth were concluded as a significant risk indicators for root caries. Copyright:

INTRODUCTION

Oral health is an important component of “Active Ageing.” One of the major dental public health problems associated with ageing is root caries. Periodic dental health surveys during the past four decades have shown a significant declining trend of edentulousness and rise in the number of retained natural teeth in the oral cavity.[123]

With an increasing number of retained teeth, there is an enhanced susceptibility to periodontal problems with gingival recession, which led root surface exposure to the oral environment and develops the root caries later stages among adults.[4] Though root caries is preventable, it is one of the debilitating dental disease and has been identified as the main cause of dental pain, leading to tooth loss in advanced stages and showed significant negative impact on oral health-related quality of life among adults.[5]

Katz RV has defined root carious lesions as “soft, progressive, destructive lesions either totally confined to the root surface or involving undermining of enamel at cementoenamel junction but clinically indicating that the lesion initiated on the root surface.”[6] Previous history of caries, loss of attachment, exposure of cementum and poor oral hygiene are risk factors for causation and progression of root caries.[7]

The reason for focus on root caries is to enlighten that root caries is qualitatively different from coronal caries. Along with the obvious topographical difference, the composition and structure of root surfaces are different from those of enamel.[8] The mineral content of the root surface is lower and the crystal size is substantially smaller than that of coronal enamel, thus root surfaces have a greater solubility than coronal surfaces.[9]

Moreover, root caries is considered as a demographically transiting health problem from adults to elderly population that affects their quality of life in later stages.[6] Full onset of oral diseases[10] and also higher risk of root caries can be observed among middle aged adults (35–44 years) owing to the long-term effects of trauma from inappropriate tooth brushing and gingival recession associated with periodontal disease.[11] Thus, it is important to investigate the prevalence and severity of root caries in adults to educate and promote good oral health in their later stages.

A systematic review by Ritter et al. reported that demographic variables (e.g., age, sex), oral health behavioral factors (e.g., tooth brushing, tobacco habits) influence the occurrence of root caries.[7] Furthermore, Gati and Vieira confirmed that there was a strong association between root caries and socioeconomic status[12] (SES). Henceforth, age, gender, oral health behavior factors, and SES are considered as risk indicators for root caries.

Therefore, the present study has been undertaken to assess the root caries experience and its association with risk indicators among middle aged South Indian adult dental patients and to correlate and compare prevalence of root caries with risk indicators among middle aged adult dental patients.

MATERIALS AND METHODS

A cross sectional study was conducted in the Out-Patient Department, Department of Oral Medicine and Radiology of Private Dental Institute from June 2016 to August 2016. A convenient sample of 191 participants aged 35–44 years was included in the study. Other inclusion criteria were 20 or more natural teeth remaining in the oral cavity and who were willing for oral examination. Subjects not medically fit and suffering with psychological disorders were excluded from the study.

Ethical approval for this study was obtained from the Institutional Review Board of Private Dental Institute and was conducted in accordance with the Declaration of Helsinki. All participants received verbal and written information about the study protocol and signed an informed-consent form prior to clinical examination. The study fulfilled the STROBE guidelines for cross sectional study design.

Demographic, dental health behavior data (frequency of tooth brushing and tobacco habits) and socioeconomic status was collected through personal interviews using a structured questionnaire.

Kuppuswamy's scale[13] was used to measure SES of families in urban communities and family income was measured, based on consumer price index for industrial workers[14] for the year 2016 (May) with the multiplication factor of 0.0735.

Clinical oral examination

The subjects were examined using plane mouth mirror and standard dental explorer on dental chair with artificial light by a single-trained examiner. Root caries and root surface restorations were evaluated using the Katz root caries index (RCI-1979)[6] on a full mouth basis. This index expresses the proportion of carious and restored root surfaces among the root surfaces exposed to the oral environment.

Statistical analysis

Statistical analysis was done using IBM SPSS Statistics for Windows, Version 20.0. Armonk, New York. The correlation between variables and RCI was determined by Karl Pearson correlation coefficient. Multiple Logistic Regression analysis was performed to determine association between RCI and variables. The P ≤ 0.05 considered as a statistically significant.

RESULTS

A total of 191 participants of which 113 (59.2%) males and 78 (40.8%) females with a mean age of 40.07 ± 3.50 years comprised the study population [Table 1]. The RCI percentage among the study population ranged from 0.76% to 5.62%, indicating a wide variation in attack rates.

Table 1

Demographic distribution of study population

Variables	Number of respondents, n (%)
Age groups (years)
<40	106 (55.5)
≥40	85 (44.5)
Mean age	40.07±3.50
Gender
Males	113 (59.2)
Females	78 (40.8)
Frequency of tooth brushing
Once a day	169 (88.5)
Twice a day	22 (11.5)
Tobacco habits
Yes	31 (16.2)
No	160 (83.8)
Socioeconomic status
Upper	16 (8.4)
Upper-middle	100 (52.3)
Lower-middle	37 (19.4)
Upper-lower	38 (19.9)
Total	191 (100)

The prevalence of untreated caries lesions on root surfaces was 8.9% (17), wherein only 1.6% (3) subjects had root surface restorations. Furthermore, 37.7% (72) subjects reported missing root surfaces (”Root surfaces characterized as missing” - M), which was significantly higher in females (46.2%; P = 0.04*) and upper-lower socioeconomic class subjects (57.9%; P = 0.01*). Though very few subjects (20;10.5%) accounted for RCI score >0 with mean score of 1.64 ± 6.81, subjects aged ≥40 years (15.3%; P = 0.05*) were more significantly vulnerable to root decay and restorations [Table 2].

Table 2

Distribution of study subjects by root caries experience and root caries index based on variables

Variables	Recession present; surface normal or sound (R-N), n (%)	Recession present; with a decayed root surface (R-D), n (%)	Recession present; with a filled root surface (R-F), n (%)	Root surfaces characterized as missing (M), n (%)	RCI, n (%)
Age groups (years)
<40	106 (100)	6 (5.7)	1 (20)	37 (34.9)	7 (6.6)
≥40	85 (100)	11 (12.9)	2 (33)	35 (41.2)	13 (15.3)
P	1	0.07	0.4	0.3	0.05*
Gender
Males	113 (100)	7 (6.2)	2 (22.2)	36 (31.9)	9 (7.9)
Females	78 (100)	10 (12.8)	1 (10)	36 (46.2)	11 (14.1)
P	1	0.1	0.7	0.04*	0.1
Frequency of tooth brushing
Once a day	169 (100)	14 (8.3)	3 (23.1)	65 (38.5)	17 (10.1)
Twice a day	22 (100)	3 (13.6)	0	7 (31.8)	3 (13.6)
P	1	0.4	0.5	0.5	0.7
Tobacco habits
Yes	31 (100)	2 (6.5)	0	15 (48.4)	2 (6.5)
No	160 (100)	15 (9.4)	3 (16.7)	57 (35.6)	18 (11.3)
P	1	0.6	0.4	0.1	0.1
Socioeconomic status
Upper	16 (100)	2 (12.5)	0	6 (37.5)	2 (12.5)
Upper-middle	100 (100)	8 (8)	2 (2)	29 (29)	10 (10)
Lower-middle	37 (100)	4 (10.8)	1 (2.7)	15 (40.5)	5 (13.5)
Upper-lower	38 (100)	3 (7.9)	0	22 (57.9)	3 (7.9)
P	1	0.9	0.7	0.01*	0.2
Total	191 (100)	17 (8.9)	3 (1.6)	72 (37.7)	20 (10.5)

*P≤0.05 Statistically significant. RCI: Root caries index

The mean number of natural teeth present in the study population was 27.16 ± 1.45. A significantly higher mean number of root surfaces did not get exposed to oral environment (77.19 ± 21.17; P = 0.0001*) among the study subjects aged <40 years. Furthermore, subjects with no history of tobacco habits had high mean number of root surfaces (73.39 ± 24.92) significantly free from gingival recession compared to subjects with tobacco habits (P = 0.0006*). When comparison was done with regard to “Recession present; surface normal or sound”(R-N) criteria, it was observed that, as age increased, the mean number of root surfaces affected with gingival recession significantly increased (45.25 ± 27.09; P = 0.0001*). Based on gender, males had significantly higher mean of root surfaces exposed to oral environment (40.74 ± 24.09) compared to females (P = 0.03*). In addition, subjects with a history of tobacco habits revealed significantly higher number of root surfaces (52.23 ± 26.49) exposed to oral environment compared to those with no history of tobacco usage (P = 0.0002*). On the other hand, upper-lower socio-economic class subjects had shown significantly higher mean number of missing root surfaces (6.21 ± 7.60; P = 0.007*) compared to subjects of other socioeconomic classes [Table 3].

Table 3

Comparison of mean number of tooth surfaces affected by root caries index scores based on variables

RCI criteria	Age groups (years), mean±SD		P	Gender, mean±SD		P	Frequency of tooth brushing, mean±SD		P
	<40	≥40		Males	Females		Once a day	Twice a day
NoR	77.19±21.17	62.25±29.26	0.0001*	67.81±26.84	74.49±25.27	0.08	70.56±26.98	70.36±21.44	0.9
Recession present; surface normal or sound (R-N)	31.56±19.90	45.25±27.09	0.0001*	40.74±24.09	33.17±24.01	0.03*	37.62±24.82	37.86±20.23	0.9
Recession present; with a decayed root surface (R-D)	0.15±0.71	0.34±1.11	0.1	0.13±0.66	0.38±1.18	0.06	0.25±0.96	0.14±0.35	0.5
Recession present; with a filled root surface (R-F)	0.03±0.29	0.39±2.99	0.2	0.29±2.60	0.04±0.34	0.3	0.21±2.14	0.0±0.0	0.6
Root surfaces characterized as missing (M)	3.05±5.29	3.78±6.42	0.3	3.01±5.94	3.90±5.62	0.3	3.34±5.83	3.64±5.78	0.8
RCI	0.53±2.84	1.68±6.93	0.1	0.95±5.83	1.17±3.85	0.7	1.09±5.35	0.68±2.41	0.7
RCI criteria	Tobacco habits, mean±SD		P	Socioeconomic status, mean±SD					P
	Yes	No		Upper	Upper-middle	Lower-middle		Upper-lower
NoR	55.84±28.97	73.39±24.92	0.0006*	69.69±28.28	75.16±23.39	65.70±25.28		63.45±31.99	0.06
Recession present; surface normal or sound (R-N)	52.23±26.49	34.83±22.87	0.0002*	39.09±25.72	33.91±21.40	42.59±24.16		42.08±29.74	0.1
Recession present; with a decayed root surface (R-D)	0.13±0.50	0.26±0.97	0.4	0.25±0.68	0.22±0.92	0.24±0.83		0.26±1.08	0.9
Recession present; with a filled root surface (R-F)	0.0±0.0	0.23±2.19	0.5	0.0±0.0	0.30±2.71	0.16±0.99		0.0±0.0	0.8
Root surfaces characterized as missing (M)	3.71±5.29	3.31±5.29	0.7	3.0±4.73	2.41±5.41	3.22±5.08		6.21±7.60	0.007*
RCI	0.16±0.61	1.22±5.55	0.2	0.30±0.83	1.45±6.97	0.73±2.07		0.60±2.19	0.7

*P≤0.05 Statistically significant. SD: Standard deviation, RCI: Root caries index, NoR: No association with recession

Decayed root surfaces were seen only in a smaller percentage of study population with a range of 3.7%–6.8% and mean score ranged from 0.08 to 0.05. Moreover, few restored root surfaces were observed on mesial, distal, and buccal surfaces with similar mean scores (3.1%; 0.08 ± 0.67) [Table 4].

Table 4

Distribution of study population based on number and mean scores of root caries index criteria by tooth surfaces

RCI criteria	Tooth surfaces
	n (%)				Mean±SD
	Mesial	Distal	Buccal	Lingual	Mesial	Distal	Buccal	Lingual
NoR	186 (97.4)	186 (97.4)	186 (97.4)	185 (96.9)	17.06±6.96	17.18±7.02	17.07±6.97	18.86±6.75
Recession present; surface normal or sound (R-N)	189 (98.9)	188 (98.4)	188 (98.4)	182 (95.3)	9.88±6.44	9.71±6.54	9.81±6.49	8.12±6.22
Recession present; with a decayed root surface (R-D)	10 (5.24)	9 (4.7)	13 (6.8)	7 (3.7)	0.08±0.36	0.07±0.33	0.08±0.32	0.05±0.24
Recession present; with a filled root surface (R-F)	6 (3.1)	6 (3.1)	6 (3.1)	3 (1.6)	0.08±0.67	0.08±0.67	0.08±0.67	0.02±0.0

SD: Standard deviation, RCI: Root caries index, NoR: No association with recession

A negative correlation (r = −0.0257) of RCI was seen with the frequency of tooth brushing. On the other hand, though positive correlation was noticed for RCI with age groups, gender, tobacco usage and SES, it was not statistically significant [Table 5]. The results of the logistic regression analysis revealed that subjects aged ≥40 years were 3.5 times significantly at greater risk (P = 0.02*) for developing root caries. Based on gender, males were at significantly higher risk for root caries compared to females (odds ratio [OR] =0.26; P = 0.03*). Moreover, with an increasing number of retained teeth was significantly associated with root caries (OR = 0.29; P = 0.04*) [Table 6].

Table 5

Correlation between root caries index scores based on variables by Karl Pearson correlation method

Independent variables	RCI scores
	r	P
Age	0.0623	0.3
Gender	0.0211	0.7
Frequency of tooth brushing	−0.0257	0.7
Tobacco habits	0.0767	0.2
Socioeconomic status	0.0384	0.5

*P≤0.05 statistically significant. RCI: Root caries index

Table 6

Risk indicators of root caries by logistic regression analysis

Variables	Root caries, n (%)	P	OR
Age groups (years)
<40	6 (5.6)	Reference
≥40	11 (12.9)	0.02*	3.50
Gender
Females	10 (12.8)	Reference
Males	7 (6.2)	0.03*	0.26
Frequency of brushing
Twice a day	3 (8.3)	Reference
Once a day	14 (13.6)	0.6	0.70
Tobacco habits
No	15 (6.4)	Reference
Yes	2 (9.4)	0.6	0.65
Socioeconomic status
Upper	2 (12.5)	Reference
Upper-middle	8 (8)	0.3	0.45
Lower-middle	4 (10.8)	0.4	0.49
Upper-lower	3 (7.9)	0.1	0.24
Number teeth present
<26	6 (16.2)	Reference
>27	11 (7.4)	0.04*	0.29
Total	17 (8.9)

*P≤0.05 statistically significant. OR: Odds ratio

DISCUSSION

The current study result revealed that, smaller proportion (20; 10.5%) of the study population had RCI of >0 with a mean number of teeth affected with root caries and root fillings was 1.64 ± 6.81. Similar scenario was noted by Keltjens et al.[15] among Netherland adults (6.8%;2.9). On the other hand, Camargo et al.[16] found that 48.5% Brazilian adults reported RCI >0 with higher mean number of teeth affected with decayed root surfaces and restored root surfaces (9.21 ± 24.53). The amount of untreated root caries in the current study was 8.9%, this finding was in agreement with previous studies by Mamai-Homata et al.[11] and Du et al.[17] among Greek (11.1%) and Chinese adults (13.1%), respectively. Only 1.6% (3) subjects had root surface restorations in the present study, whereas 26% of Danish adults[18] reported root surface restorations. This difference may be attributed to geographical and socio-behavioral lifestyle factors or utilization of oral health care services.[19]

In this study, age was found to be a positive significant risk factor (OR – 3.50; P = 0.02*) for root caries. Also, significantly higher mean number of teeth surfaces were exposed to the oral environment with increasing age (<40 years [NoR - 77.19 ± 21.17; P = 0.0001*]; ≥40 years [R-N - 45.25 ± 27.09; P = 0.0001*]). This could be due to the cumulative effect of faulty tooth brushing habit and poor maintenance of oral health with age.[20] Likewise, studies by Sugihara et al.[21] reported a significant increase in the prevalence of root caries with increasing age among Japanese population (P = 0.001).

This study confessed, though a higher proportion of females (10; 12.8%) had root caries, males were at a significantly higher risk for root caries (OR = 0.26; P = 0.03*) as they had a greater number of tooth surfaces affected with gingival recession (40.74 ± 24.09; P = 0.03*). This could be due to deleterious habits such as tobacco use seen mostly in males. Further, 46.2% females had significantly higher number of missing teeth (3.01 ± 5.94; P = 0.04*) compared to males. Similarly, among Turkish[19] and German[22] population, risk of root caries was more obvious in males than in females.

In this study, a significantly higher mean number of tooth surfaces were exposed into the oral cavity among tobacco users (52.23 ± 26.49; P = 0.0002*). This reason attributing to this could be due to the association of tobacco use with increased pocket depths, loss of periodontal attachment.[23] Similarly, Du et al.[17] also regarded tobacco habits as a significant risk factor for root caries among Chinese population.

Among Brazilian adults,[7] root caries was seen frequently in maxillary molars. Whereas, maxillary incisors and canines were more commonly affected with root caries in the present study [Figure 1]. Nonetheless, studies by Katz RV et al6, Du MQ et al[17] and Splieth CH et al22 revealed that mandibular molars and premolars were mostly affected with root caries.

Figure 1

Root caries index distribution in the study population based on the type of teeth affected with root caries and fillings. The root caries index percentage among the study population ranged from 0.76% to 5.62%, indicating a wide variation in attack rates. Based on type of teeth, upper arch incisors and canines were more affected with root surface caries and fillings, whereas premolars and molars were commonly affected in lower arch

In our study, higher amount of untreated root caries was seen in upper socio-economic class, which was in line with Shah and Sundaram [Figure 2],[24] who observed a significant optimal correlation between root caries and higher socioeconomic class subjects (65.7%; P = 0.0001).

Figure 2

Distribution of study subjects based on number of teeth and tooth surfaces with root Decay. Based on number of teeth and tooth surfaces with root decay, females and upper-middle class subjects reported higher number of teeth and tooth surfaces were suffered with root decay ([20;30]; [15;22], respectively)

Our study showed that more number of retained teeth in the oral cavity had been considered as a significant risk factor for root caries (OR = 0.29; P = 0.04*). This finding was in consistency with the studies on Turkish[19] and Boston[20] population.

However, the present study acknowledges certain limitations like being a cross-sectional study, the causal relationship cannot be measured and further systemic conditions such as diabetes and hypertension were not taken into consideration which might influence the findings. Also, the Katz RCI used in the present study does not distinguish whether the fillings (R-F) on the root surfaces are due to caries or cervical abrasion. Furthermore, missing root surfaces were not included in RCI, which might influence actual root caries experience. The study was conducted in a single dental institution that had led to selection bias; therefore, the results should be generalized with caution. Thus, there is a need for further studies on larger population to establish a relationship between root caries and risk indicators.

CONCLUSION

With the keen observation of the current study revealed that the proportion of untreated caries was quite high (8.9%) with overall RCI 10.5% which draws more attention to address the issue. As sever tooth loss and edentulism are the leading causes of years lived with disability among elderly. Therefore, to tackle the above situation primary preventive measures like oral health education programs emphasizing on proper tooth brushing with fluoride dentifrice, importance of balanced diet and regular visits to dentists should be focused, which can hinder the disease burden and improve oral health-related quality of life.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.