an analysis of the etiological and predisposing factors
TRANSCRIPT
Bamise1 The Journal of Contemporary Dental Practice, Volume 9, No.
5, July 1, 2008
An Analysis of the Etiological and Predisposing Factors Related to Dentin Hypersensitivity
Aim: To determine the prevalence of different etiological factors of dentin hypersensitivity in patients and to provide information on their association with dentin hypersensitivity.
Methods and Materials: Twenty-nine patients (17 male, 12 female) suffering from pain of dentin hypersensitivity were recruited to participate in the study. A relevant history was taken and dentin hypersensitivity confirmed by using air-blast and tactile stimuli.
Results: All patients were right-handed. The left side of the mouth showed a preponderance of gingival recession, abrasion, abfraction, and erosion while more teeth on the right side showed attrition. Gingival recession and attrition were common among the molars, abrasions among the molars and premolars, abfraction among the premolars, while erosive lesions were predominantly found among the incisors.
A total of 911 teeth were examined in the 29 subjects presenting with dentin hypersensitivity. The following conditions were found to be associated with the dentin hypersensitivity: 43 of 117 teeth (36.8%) with gingival recession; 41 of 99 teeth (41.4%) with attrition; 40 of 67 teeth (59.7%) with abrasion; 16 of 25 teeth (64%) with abfraction; and 32 teeth had erosive lesions all associated with hypersensitivity.
Abstract
© Seer Publishing
2 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
Introduction Dentin hypersensitivity has been described as a condition in which a sound, exposed dentinal surface is sensitive to stimuli that would normally cause no discomfort.1 Usually, no obvious cause can be identified for this condition;2 Addy3
described it as a tooth wear phenomenon. By definition two conditions need to be satisfied for dentin hypersensitivity to occur: dentin has to become exposed by loss of enamel or periodontal tissues and the dentin tubule system has to be opened and be patent to the pulp.4
The most implicated physical/chemical process causing dentin exposure is dental erosion acting alone or synergistically with other factors such as abrasion and attrition. Enamel erosion is characterized by acid-mediated surface softening progressing to irreversible loss of surface tissue if left unchecked potentially exposing the underlying dentin.5 It is currently believed to be the major factor involved in tooth wear.6
Traditionally, potential factors causing erosion have been described as originating from the diet, environment, and from regurgitation.7 Erosion
may also be due to either extrinsic or intrinsic acids.8,9 Erosion results in shallow, rounded lesions,10 and it is suggested7 when an erosive factor is present ‘cupping’ or ‘grooves’ form in the dentin with the base of the defect not in contact with the opposing tooth.
Attrition describes the wear of teeth at sites of direct contact between teeth.11 It is associated with flattening of the cusp tips or incisal edges and localized facets on the occlusal or palatal surfaces.
Abrasion describes the wear of teeth caused by objects other than another tooth.11 Most interest in abrasion has centered around the effects of tooth brushing with toothpaste. Typical toothbrush abrasion lesions are side dependent, for example being greater on the left-side in right-handed people. The buccal cervical areas of the teeth are the sites of predilection. Cervical lesions caused by an abrasive tend to be angular and ‘v’-shaped.
Abfraction or cervical stress lesions have been hypothesized as an etiological factor in tooth wear.12,13 The process is thought to involve eccentric occlusal loading leading to cusp flexure. This flexure results in damage to the enamel rods at the gum line resulting in their loosening and consequent flaking away of the tooth structure. It is difficult to diagnose such lesions properly, but generally, in cases where a deep v-shaped cervical notch is present or when cervical restorations are repeatedly lost, the practitioner should look for wear facets or other signs of occlusal trauma.14
Conclusion: Gingival recessions followed by attrition were the most commonly found etiological factors leading to dentin hypersensitivity. Erosive lesions were mostly associated with dentin hypersensitivity. A statistically significant relationship exists between dentin hypersensitivity, tooth wear lesions, and gingival recession.
Clinical Significance: This study provides clinical evidence supporting the notion of dentin hypersensitivity being a tooth wear phenomenon. Therefore, successful preventive and management strategies for sufferers of dentin hypersensitivity must take into consideration causal factors for tooth wear and gingival recession.
Keywords: Etiological factors, dentin hypersensitivity, tooth wear, gingival recession
Citation: Bamise CT, Olusile AO, Oginni AO. An Analysis of the Etiological and Predisposing Factors Related to Dentin Hypersensitivity. J Contemp Dent Pract 2008 July; (9)5:052-059.
3 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
included the consumption of orange juice, carbonated beverages, and chewable vitamin C. The type of toothbrush, toothbrushing technique, and handedness of the patient were noted.
A past medical history was taken to ascertain any underlying systemic conditions such as diabetes mellitus, hypertension, blood dyscrasias, allergies, bronchial asthma, hiatus hernia, astroesophageal reflux disease (GERD), pregnancy, and current medications.
Intraorally, all remaining teeth were examined with their numbers, position, mobility, and occlusal relations noted. Any evidence of gingival recession, caries, attrition, erosion, abrasion, abfraction, fractures, chipping, and dentin hypersensitivity were also recorded. Teeth having caries, cracks or fractures, extensive and unsatisfactory restorations, and mobility were excluded. The suspected sites on the teeth were stimulated by an air-blast from the air-water syringe of the dental unit and by scratching the exposed area with a dental probe until the patient reported the exact discomfort that precipitated their initial dental visit. All the teeth with dentin hypersensitivity and surfaces involved were recorded.
Frequencies and proportions were calculated. Associations between discreet variables were tested using the Chi square test. In all cases a p-value of less than 0.05 (p=<.05) was taken as significant.
Results Patients who consumed orange juice either daily or at least once a week had 29 (90.6%) teeth with erosive lesions. Patients who consumed carbonated cola drinks daily or at least once a week had 16 (50%) teeth with erosive lesions. In patients who took chewable vitamin C daily or at least once a week had 13 (40.6%) teeth with erosive lesions.
Patients who claimed to use a hard bristle toothbrush had 45 (38.5%) teeth with gingival recession and 27 (40.3%) teeth with abrasion. Patients who used a soft bristle toothbrush had six (5.1%) teeth with gingival recession and two (3%) teeth with abrasion. Patients who used toothbrushes indiscriminately had 66 (56.4%)
Gingival recession and subsequent root surface exposure allow more rapid and extensive exposure of dentinal tubules because the cementum layer overlying the root surface is thin and can be easily removed.15
Dentin hypersensitivity has also been described as the most common side effect of tooth whitening.16,17 Other causative factors which seldom act in isolation include bruxing, side effects of medication, aging, genetic conditions, and periodontal disease or procedures.18
There is very little direct clinical evidence of the association of these suggested etiological factors with dentin hypersensitivity. The purpose of this study was to determine the prevalence of the etiological and predisposing factors of hypersensitivity and their associations with sufferers of this condition.
Methods and Materials This study was conducted in the Conservative Dentistry unit of the Obafemi Awolowo University Teaching Hospital complex in Ile Ife, Nigeria over a 12 month period. A total of 29 patients (17 males, 12 females) suffering from dentin hypersensitivity referred from the Oral Diagnosis department were recruited to participate in the study. The study protocol was approved by the Ethics Committee of the Hospital and informed consent from all the patients was obtained prior to data collection.
Dentin hypersensitivity was diagnosed by intraoral testing done by the principal investigator (PI) and confirmed by at least one other investigator. A detailed relevant history was taken, which
4 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
hypersensitivity. The upper right quadrant had the highest number of attrited teeth.
Sixty-seven teeth had cervical abrasion with the upper left quadrant having the highest number of teeth affected, which was statistically significant different from the upper right quadrant. Forty (59.7%) teeth had sensitive abrasive lesions.
Twenty-five teeth with abfractions were seen with the upper left quadrant having the highest number of teeth affected. Sixteen (64%) teeth with abfraction had related dentin hypersensitivity.
Thirty-two teeth had erosive lesions with all of them having associated dentin hypersensitivity. The upper left quadrant had the highest number of teeth with erosion. Erosive lesions had a 45% predilection for buccal/labial surfaces, 37% for occlusal surfaces, and 6% for palatal/lingual surfaces (Figure 1).
There was a statistically significant relationship of dentin hypersensitivity with gingival recession and tooth wear (p=0.05, Chi square test).
teeth with gingival recession and 38 (56.7%) teeth with abrasion.
Sixty-five (97%) teeth showing abrasion were found in patients who cleaned their teeth with a toothbrush and toothpaste. Patients who used a toothbrush and toothpaste plus a chewing stick had two (3%) teeth with abrasion. None of the patients used a chewing stick alone.
All patients were right-handed. The left side of the mouth showed a preponderance of gingival recession, abrasion, abfraction, and erosion while more teeth on the right side showed attrition (Table 1).
Tables 1 and 2 show 911 teeth from 29 patients who participated in the study. A total of 117 teeth had gingival recession with the upper left quadrant having the highest number of teeth affected. Forty-three (36.8%) teeth had dentin hypersensitivity related to the gingival recession.
Ninety-nine teeth had attrited surfaces out of which 41 (41.4%) had an associated dentin
Table 1. Quadrants and right and left-sided distributions of gingival recession, attrition, abrasion, abfraction, and erosion.
5 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
it and for the clinicians providing treatment. Understanding the burden of the various predisposing factors and recognizing the degree of their association are an integral part of total patient care. The aim of the present study was to provide more information on these factors.
Since only 29 patients were recruited to participate in the study it suffers a limitation. This
Gingival recession and attrition were predominantly found among molars; abrasive lesions among molars and premolars; abfraction among premolars; while erosive lesions were predominantly found among incisors (Table 2).
Discussion Dentin hypersensitivity is a problem posing a number of challenges for those who suffer from
Table 2. Distribution of gingival recession, attrition, abrasion, abfraction, erosion, and their involvement in dentin hypersensitivity.
Figure 1. Predilection of erosive lesions for tooth surfaces.
6 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
with toothpaste has been considered to be a prime etiological agent in both abrasive tooth wear and gingival recession.22 Levitch, et al.23 reported the association of toothbrushing with tooth wear exists in subjects who brush their teeth frequently for a longer period and use a scrubbing technique.
Interaction of these factors might have contributed to the high percentage of cervical abrasion lesions and gingival recessions found in subjects using a hard bristle toothbrush and those who used toothbrushes indiscriminately. This agrees with the findings of Bradley et al.20 and Goutoudi et al.24
where hard toothbrush use has been implicated in gingival recession and abrasion as is dentin hypersensitivity.
Use of a chewing stick has been mentioned as a cause of tooth wear in the dental literature25 and gingival recession.26 Such a correlation could not be ascertained in this study because none of the subjects in the study used a chewing stick alone.
The preponderant finding of attrition in molars/ premolars can possibly be explained by the high fibrous, coarse, or gritty diet common in the Nigerian environment. This result is also similar to the findings of previous studies among Nigerians. Kumar and Ana,27 in their study of prevalence of attrition in two Nigerian rural areas, reported attrition is marked in molars. Mandibular molars and first molars were said to be the most attrited teeth, and they suggested the differential diagnoses of attrition be considered for pain in the mouth. Oginni et al.28 reported attrition to be the most prevalent form of tooth wear occurring mostly on the posterior teeth that bear the brunt of masticatory forces.29 Attrition occurs due to tooth- to-tooth contact during function30 and it is said to be commonly seen in the developing countries and in the elderly.31
The premolars and canines were the most affected by abrasion in this study. Addy et al.32 had a similar result due to the position of these teeth within the dental arch where they receive the most attention during cleaning.
Abfractive lesions were predominantly seen among the posterior teeth on the left side and in the upper left quadrants. This is consistent with the result of an earlier study done in the same hospital.28
could probably be explained by the low prevalence of teeth responding positively to the objective diagnosis of dentin hypersensitivity. This was also evident by a significant percentage of tooth wear lesions with exposed dentin surfaces which were not sensitive as observed in the study.
The cause of dentin hypersensitivity is attributed to exposed dentinal tubules found in areas where tooth structure has been lost. There are potentially numerous and varied etiological and predisposing factors of dentin hypersensitivity, certainly no prime cause has been identified.2
During the diagnosis of dentin hypersensitivity and identification of associated etiological factors for this study, the dominant factors were identified by their characteristic appearance and recorded. The wear of an individual’s teeth rarely results from a single cause although one is likely to predominate. This limitation was envisaged during the diagnosis; hence, there was inter-examiner agreement (the PI and at least one other investigator) in the identification of the dominant cause.
The results indicated patients consuming orange juice and carbonated cola beverages had the highest number of tooth surface loss. This is similar to the result of a study by Addy et al.19
where they demonstrated citrus fruit juices were capable of rapidly dissolving the dentin smear layer within a few minutes and carbonated cola drink was less erosive.
Toothbrush characteristics, i.e., hard toothbrush20
and toothbrushing techniques, are major variables in hard and soft tissue damage.21
Since toothbrushing is usually performed with toothpaste, incorrect or vigorous toothbrushing
7 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
that dentin hypersensitivity shows a predilection for certain oral sites that may be of etiological relevance. It is not surprising incisors were mostly affected by erosion, canines and premolars were preponderantly involved in gingival recession and abrasion. Molars were observed as the most attrited teeth.
The dental management of patients where such factors, i.e., tooth wear and gingival recession are overwhelming has proven difficult for clinicians for many years, and the problem seems to be increasing because the population is retaining more natural teeth into old age.38 An increased understanding of the relationship of these entities with dentin hypersensitivity is essential to its prevention and effective management.
Conclusion Within the limitations of this study, the prevalence and distribution of the different etiological factors of dentin hypersensitivity in patients that presented with pain due to dentin hypersensitivity were obtained. Gingival recession followed by attrition were the most common etiological factors found while erosive lesions showed the most frequent association with dentin hypersensitivity. A statistically significant relationship exists between dentin hypersensitivity, tooth wear lesions, and gingival recession. There is still a need to conduct further studies to know the prevalence of tooth wear lesions and gingival recession in the general population.
Clinical Significance The etiology of dentin hypersensitivity is poorly understood. This study provides clinical evidence supporting the notion of dentin hypersensitivity being a tooth wear phenomenon. Therefore, successful preventive and management strategies for sufferers of dentin hypersensitivity must take into consideration causal factors for tooth wear and gingival recession.
The incisors and canines were predominantly affected by erosion. Smooth surfaces of anterior teeth have been shown to be particularly vulnerable to attack by acids during the consumption of acidic beverages which may cause erosion of tooth tissue.33 Most of the erosive lesions in the present study can be attributed to dietary erosion because none of the patients had a history of intrinsic acid production or occupational exposure to acids. Also, a significant relationship was observed between patients with a history of dietary acid ingestion and tooth erosion.
Some examined teeth had gingival recession, abrasions, abfractions, and attrited lesions that were not sensitive. Absi et al.34 stated not all exposed dentin is sensitive and in areas of sensitive dentin the number of tubules open at the surface was approximately eight times that of non- sensitive dentin. Furthermore, they indicated the mean diameter of open tubules in sensitive dentin was twice those as in non-sensitive dentin. They concluded the more open dentinal tubules there are on the surface and the greater the diameter, the greater the propensity for tubular fluid flow with a given stimulus.
A similar distribution of gingival recession and abrasion was found in the present study. The upper left quadrant had the highest number of teeth with gingival recession and abrasion. These conditions along with dentin hypersensitivity have been shown to be more common on the left than on the right side of the dental arches.35 Addy4 then suggested such findings showed toothbrushing is associated with dentin hypersensitivity. This is supported by the fact all the patients in this study were right handed and right handed brushers are known to brush the left buccal surfaces more effectively than on right side.32,36
Generally, low percentages of the etiological and predisposing factors were observed but their distributions agree with the summation of Addy37 in
8 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
References 1. Flynn J, Galloway R, Ochardson R. The incidence of hypersensitive teeth in the West of Scotland.
J Dent 1985; 13:230-236. 2. Dababneh RH, Khouri AT, Addy M. Dentin hypersensitivity an enigma? A review of terminology,
epidemiology, mechanisms, aetiology and management. Br Dent J 1999; 187:606-611. 3. Addy M. Tooth brushing, tooth wear and dentin hypersensitivity--are they associated? Int Dent J.
2005; 55(4 Suppl 1):261-7. 4. Addy M. Dentin hypersensitivity: new perspective on an old problem. Int Dent J 2002; 52:367-375. 5. Barbour ME, Rees GD. The role of erosion, abrasion and attrition in tooth wear. J Clin Dent. 2006;
17(4):88-93. 6. Addy M, Hunter ML. Can tooth brushing damage your health? Effects on oral and dental tissues.
Int Dent J 2003; 53(supplement 3):177–86. 7. Mair LH. Wear in dentistry – Current terminology. J Dent 1992; 20:140-144. 8. Zero DT. Etiology of dental erosion – extrinsic factors. Eur J Oral Sciences 1996; 104:162-177. 9. Scheutzel P. Etiology of dental erosion – intrinsic factors. Eur J Oral Sci 1996; 104:178-190. 10. Kelleher M, Bishop K. Tooth surface loss: an overview. Br Dent J 1999; 186:61-66. 11. Smith BGN. Tooth wear: aetiology and diagnosis. Dent Update 1989; 16:204-212. 12. Grippo JO. Abfractions: A new classification of hand tissue lesions of teeth. J Prosthetic Dent 1991;
3:14-19. 13. Braem M, Lambrechts P, Vanherle G. Stress induced cervical lesions. J Prosthet Dent 1992;
67:718-722. 14. Milosevic A. Toothwear: Aetiology and presentation. Dent Update 1998; 25:6-11. 15. Bevenius J, Lindskog S, Hultenby K. The Micromorphology in vivo of the buccocervival region of
premolar teeth in young adults. A replica study by scanning election microcopy. Acta Odont Scand 1995; 52:323-334.
16. Haywood VB. Treating sensitivity during tooth whitening. Compend Contin Educ Dent. 2005; 26(9):11-20.
17. Tredwin CJ, Naik S, Lewis NJ, Scully C. Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues. Br Dent J. 2006; 200(7):371-6.
18. Sykes LM. Dentin hypersensitivity: a review of its aetiology, pathogenesis and management. SADJ. 2007; 62(2):066-71.
19. Addy M, Absi EG, Adams D. Dentin hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentin. J Clin Periodontol 1987; 14:274-279.
20. Bradley TP, William BG, Everett BH. Examining the prevalence and characteristics of abfraction-like cervical lesions in a population of U.S. veterans. J Am Dent Assoc 2001; 132(12):1694-1701.
21. Hunter ML, Addy M, Pickles MJ, Joiner A. The role of toothpastes and toothbrushes in the aetiology of toothwear. Int Dent J 2002; 52:399-405.
22. Bergenholtz A. Mechanical cleaning in oral hygiene. In: Frandsen A, (ed) Oral hygiene. Munksgaard: Copenhagen 1976; 27-60.
23. Levitch LC, Bader JD, Shugars DA, Heymann HO. Non carious cervical lesions. J Dent 1994; 22:195-207.
24. Goutoudi P, Koidis PT, Konstantinidis A. Gingival recession: a cross-sectional clinical investigation. Eur J Prosthodont Rest Dent 1997; 5:57-61.
25. Almas K, Al-Lafi TR. The natural toothbrush. World health forum 1995; 16:206-210. 26. Oji C. Chewing sticks and oral health – review. Nigerian Dental Journal 1997; 11:27-31. 27. Kumar V, Ana JR. Prevalence and severity of tooth attrition in Nigerian rural areas. Niger Med J.
1978; 8:557-562. 28. Oginni AO, Olusile AO, Udoye CI. Non-carious cervical lesion in a Nigerian population: Abrasion or
Abfraction. Int Dent J 2003; 53:275-279. 29. Odusanya SA, Abayomi IO. Tooth attrition among rural Nigerians. Afr Dent J 1987; 1:73-78. 30. Smith BGN, Knight JK. A comparison of patterns of toothwear with the etiological factors. Br Dent J
1984; 157:16-19.
9 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
31. Cawson RA, Odell EW. Essentials of oral pathology and oral medicine. Churchill Livingstone 1998; 60-61.
32. Addy M, Griffiths G, Dummer P, Kingdom A, Shaw WC. The distribution of plaque and gingivitis and the influence of toothbrushing hand in a group of Southwales 11-12 year old children. J Clin Periodontol 1987; 14:564-572.
33. Eccles JD. Tooth surface loss from abrasion, attrition and erosion. Dent update 1982; 9:373-381. 34. Absi EG, Addy M, Adams D. Dentin hypersensitivity. A study of the patency of dentinal tubules in
sensitive and non-sensitive cervical dentin. J Clin Periodontol 1987; 14:280-284. 35. Addy M, Mostafa P, Newcombe RG. Dentin hypersensitivity: the distribution of recession, sensitivity
and plaque. J Dent 1987; 15:242-248. 36. Addy M, Dummer PM, Hunter ML, Kingdom A, Shaw WC. The effect of toothbrushing frequency,
toothbrushing hand, sex and social class on the incidence of plaque, gingivitis and pocketing in adolescents: a longitudinal cohort study. Community Dental Health 1990; 7:237-247.
37. Addy M. Clinical aspects of dentin hypersensitivity. Proc Finn Dent Soc 1992; 88(suppl 1):23-30. 38. Smith BGN, Knight JK. An index for measuring the wear of teeth. Br Dent J 1984; 156:435-438.
About the Authors
An Analysis of the Etiological and Predisposing Factors Related to Dentin Hypersensitivity
Aim: To determine the prevalence of different etiological factors of dentin hypersensitivity in patients and to provide information on their association with dentin hypersensitivity.
Methods and Materials: Twenty-nine patients (17 male, 12 female) suffering from pain of dentin hypersensitivity were recruited to participate in the study. A relevant history was taken and dentin hypersensitivity confirmed by using air-blast and tactile stimuli.
Results: All patients were right-handed. The left side of the mouth showed a preponderance of gingival recession, abrasion, abfraction, and erosion while more teeth on the right side showed attrition. Gingival recession and attrition were common among the molars, abrasions among the molars and premolars, abfraction among the premolars, while erosive lesions were predominantly found among the incisors.
A total of 911 teeth were examined in the 29 subjects presenting with dentin hypersensitivity. The following conditions were found to be associated with the dentin hypersensitivity: 43 of 117 teeth (36.8%) with gingival recession; 41 of 99 teeth (41.4%) with attrition; 40 of 67 teeth (59.7%) with abrasion; 16 of 25 teeth (64%) with abfraction; and 32 teeth had erosive lesions all associated with hypersensitivity.
Abstract
© Seer Publishing
2 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
Introduction Dentin hypersensitivity has been described as a condition in which a sound, exposed dentinal surface is sensitive to stimuli that would normally cause no discomfort.1 Usually, no obvious cause can be identified for this condition;2 Addy3
described it as a tooth wear phenomenon. By definition two conditions need to be satisfied for dentin hypersensitivity to occur: dentin has to become exposed by loss of enamel or periodontal tissues and the dentin tubule system has to be opened and be patent to the pulp.4
The most implicated physical/chemical process causing dentin exposure is dental erosion acting alone or synergistically with other factors such as abrasion and attrition. Enamel erosion is characterized by acid-mediated surface softening progressing to irreversible loss of surface tissue if left unchecked potentially exposing the underlying dentin.5 It is currently believed to be the major factor involved in tooth wear.6
Traditionally, potential factors causing erosion have been described as originating from the diet, environment, and from regurgitation.7 Erosion
may also be due to either extrinsic or intrinsic acids.8,9 Erosion results in shallow, rounded lesions,10 and it is suggested7 when an erosive factor is present ‘cupping’ or ‘grooves’ form in the dentin with the base of the defect not in contact with the opposing tooth.
Attrition describes the wear of teeth at sites of direct contact between teeth.11 It is associated with flattening of the cusp tips or incisal edges and localized facets on the occlusal or palatal surfaces.
Abrasion describes the wear of teeth caused by objects other than another tooth.11 Most interest in abrasion has centered around the effects of tooth brushing with toothpaste. Typical toothbrush abrasion lesions are side dependent, for example being greater on the left-side in right-handed people. The buccal cervical areas of the teeth are the sites of predilection. Cervical lesions caused by an abrasive tend to be angular and ‘v’-shaped.
Abfraction or cervical stress lesions have been hypothesized as an etiological factor in tooth wear.12,13 The process is thought to involve eccentric occlusal loading leading to cusp flexure. This flexure results in damage to the enamel rods at the gum line resulting in their loosening and consequent flaking away of the tooth structure. It is difficult to diagnose such lesions properly, but generally, in cases where a deep v-shaped cervical notch is present or when cervical restorations are repeatedly lost, the practitioner should look for wear facets or other signs of occlusal trauma.14
Conclusion: Gingival recessions followed by attrition were the most commonly found etiological factors leading to dentin hypersensitivity. Erosive lesions were mostly associated with dentin hypersensitivity. A statistically significant relationship exists between dentin hypersensitivity, tooth wear lesions, and gingival recession.
Clinical Significance: This study provides clinical evidence supporting the notion of dentin hypersensitivity being a tooth wear phenomenon. Therefore, successful preventive and management strategies for sufferers of dentin hypersensitivity must take into consideration causal factors for tooth wear and gingival recession.
Keywords: Etiological factors, dentin hypersensitivity, tooth wear, gingival recession
Citation: Bamise CT, Olusile AO, Oginni AO. An Analysis of the Etiological and Predisposing Factors Related to Dentin Hypersensitivity. J Contemp Dent Pract 2008 July; (9)5:052-059.
3 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
included the consumption of orange juice, carbonated beverages, and chewable vitamin C. The type of toothbrush, toothbrushing technique, and handedness of the patient were noted.
A past medical history was taken to ascertain any underlying systemic conditions such as diabetes mellitus, hypertension, blood dyscrasias, allergies, bronchial asthma, hiatus hernia, astroesophageal reflux disease (GERD), pregnancy, and current medications.
Intraorally, all remaining teeth were examined with their numbers, position, mobility, and occlusal relations noted. Any evidence of gingival recession, caries, attrition, erosion, abrasion, abfraction, fractures, chipping, and dentin hypersensitivity were also recorded. Teeth having caries, cracks or fractures, extensive and unsatisfactory restorations, and mobility were excluded. The suspected sites on the teeth were stimulated by an air-blast from the air-water syringe of the dental unit and by scratching the exposed area with a dental probe until the patient reported the exact discomfort that precipitated their initial dental visit. All the teeth with dentin hypersensitivity and surfaces involved were recorded.
Frequencies and proportions were calculated. Associations between discreet variables were tested using the Chi square test. In all cases a p-value of less than 0.05 (p=<.05) was taken as significant.
Results Patients who consumed orange juice either daily or at least once a week had 29 (90.6%) teeth with erosive lesions. Patients who consumed carbonated cola drinks daily or at least once a week had 16 (50%) teeth with erosive lesions. In patients who took chewable vitamin C daily or at least once a week had 13 (40.6%) teeth with erosive lesions.
Patients who claimed to use a hard bristle toothbrush had 45 (38.5%) teeth with gingival recession and 27 (40.3%) teeth with abrasion. Patients who used a soft bristle toothbrush had six (5.1%) teeth with gingival recession and two (3%) teeth with abrasion. Patients who used toothbrushes indiscriminately had 66 (56.4%)
Gingival recession and subsequent root surface exposure allow more rapid and extensive exposure of dentinal tubules because the cementum layer overlying the root surface is thin and can be easily removed.15
Dentin hypersensitivity has also been described as the most common side effect of tooth whitening.16,17 Other causative factors which seldom act in isolation include bruxing, side effects of medication, aging, genetic conditions, and periodontal disease or procedures.18
There is very little direct clinical evidence of the association of these suggested etiological factors with dentin hypersensitivity. The purpose of this study was to determine the prevalence of the etiological and predisposing factors of hypersensitivity and their associations with sufferers of this condition.
Methods and Materials This study was conducted in the Conservative Dentistry unit of the Obafemi Awolowo University Teaching Hospital complex in Ile Ife, Nigeria over a 12 month period. A total of 29 patients (17 males, 12 females) suffering from dentin hypersensitivity referred from the Oral Diagnosis department were recruited to participate in the study. The study protocol was approved by the Ethics Committee of the Hospital and informed consent from all the patients was obtained prior to data collection.
Dentin hypersensitivity was diagnosed by intraoral testing done by the principal investigator (PI) and confirmed by at least one other investigator. A detailed relevant history was taken, which
4 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
hypersensitivity. The upper right quadrant had the highest number of attrited teeth.
Sixty-seven teeth had cervical abrasion with the upper left quadrant having the highest number of teeth affected, which was statistically significant different from the upper right quadrant. Forty (59.7%) teeth had sensitive abrasive lesions.
Twenty-five teeth with abfractions were seen with the upper left quadrant having the highest number of teeth affected. Sixteen (64%) teeth with abfraction had related dentin hypersensitivity.
Thirty-two teeth had erosive lesions with all of them having associated dentin hypersensitivity. The upper left quadrant had the highest number of teeth with erosion. Erosive lesions had a 45% predilection for buccal/labial surfaces, 37% for occlusal surfaces, and 6% for palatal/lingual surfaces (Figure 1).
There was a statistically significant relationship of dentin hypersensitivity with gingival recession and tooth wear (p=0.05, Chi square test).
teeth with gingival recession and 38 (56.7%) teeth with abrasion.
Sixty-five (97%) teeth showing abrasion were found in patients who cleaned their teeth with a toothbrush and toothpaste. Patients who used a toothbrush and toothpaste plus a chewing stick had two (3%) teeth with abrasion. None of the patients used a chewing stick alone.
All patients were right-handed. The left side of the mouth showed a preponderance of gingival recession, abrasion, abfraction, and erosion while more teeth on the right side showed attrition (Table 1).
Tables 1 and 2 show 911 teeth from 29 patients who participated in the study. A total of 117 teeth had gingival recession with the upper left quadrant having the highest number of teeth affected. Forty-three (36.8%) teeth had dentin hypersensitivity related to the gingival recession.
Ninety-nine teeth had attrited surfaces out of which 41 (41.4%) had an associated dentin
Table 1. Quadrants and right and left-sided distributions of gingival recession, attrition, abrasion, abfraction, and erosion.
5 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
it and for the clinicians providing treatment. Understanding the burden of the various predisposing factors and recognizing the degree of their association are an integral part of total patient care. The aim of the present study was to provide more information on these factors.
Since only 29 patients were recruited to participate in the study it suffers a limitation. This
Gingival recession and attrition were predominantly found among molars; abrasive lesions among molars and premolars; abfraction among premolars; while erosive lesions were predominantly found among incisors (Table 2).
Discussion Dentin hypersensitivity is a problem posing a number of challenges for those who suffer from
Table 2. Distribution of gingival recession, attrition, abrasion, abfraction, erosion, and their involvement in dentin hypersensitivity.
Figure 1. Predilection of erosive lesions for tooth surfaces.
6 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
with toothpaste has been considered to be a prime etiological agent in both abrasive tooth wear and gingival recession.22 Levitch, et al.23 reported the association of toothbrushing with tooth wear exists in subjects who brush their teeth frequently for a longer period and use a scrubbing technique.
Interaction of these factors might have contributed to the high percentage of cervical abrasion lesions and gingival recessions found in subjects using a hard bristle toothbrush and those who used toothbrushes indiscriminately. This agrees with the findings of Bradley et al.20 and Goutoudi et al.24
where hard toothbrush use has been implicated in gingival recession and abrasion as is dentin hypersensitivity.
Use of a chewing stick has been mentioned as a cause of tooth wear in the dental literature25 and gingival recession.26 Such a correlation could not be ascertained in this study because none of the subjects in the study used a chewing stick alone.
The preponderant finding of attrition in molars/ premolars can possibly be explained by the high fibrous, coarse, or gritty diet common in the Nigerian environment. This result is also similar to the findings of previous studies among Nigerians. Kumar and Ana,27 in their study of prevalence of attrition in two Nigerian rural areas, reported attrition is marked in molars. Mandibular molars and first molars were said to be the most attrited teeth, and they suggested the differential diagnoses of attrition be considered for pain in the mouth. Oginni et al.28 reported attrition to be the most prevalent form of tooth wear occurring mostly on the posterior teeth that bear the brunt of masticatory forces.29 Attrition occurs due to tooth- to-tooth contact during function30 and it is said to be commonly seen in the developing countries and in the elderly.31
The premolars and canines were the most affected by abrasion in this study. Addy et al.32 had a similar result due to the position of these teeth within the dental arch where they receive the most attention during cleaning.
Abfractive lesions were predominantly seen among the posterior teeth on the left side and in the upper left quadrants. This is consistent with the result of an earlier study done in the same hospital.28
could probably be explained by the low prevalence of teeth responding positively to the objective diagnosis of dentin hypersensitivity. This was also evident by a significant percentage of tooth wear lesions with exposed dentin surfaces which were not sensitive as observed in the study.
The cause of dentin hypersensitivity is attributed to exposed dentinal tubules found in areas where tooth structure has been lost. There are potentially numerous and varied etiological and predisposing factors of dentin hypersensitivity, certainly no prime cause has been identified.2
During the diagnosis of dentin hypersensitivity and identification of associated etiological factors for this study, the dominant factors were identified by their characteristic appearance and recorded. The wear of an individual’s teeth rarely results from a single cause although one is likely to predominate. This limitation was envisaged during the diagnosis; hence, there was inter-examiner agreement (the PI and at least one other investigator) in the identification of the dominant cause.
The results indicated patients consuming orange juice and carbonated cola beverages had the highest number of tooth surface loss. This is similar to the result of a study by Addy et al.19
where they demonstrated citrus fruit juices were capable of rapidly dissolving the dentin smear layer within a few minutes and carbonated cola drink was less erosive.
Toothbrush characteristics, i.e., hard toothbrush20
and toothbrushing techniques, are major variables in hard and soft tissue damage.21
Since toothbrushing is usually performed with toothpaste, incorrect or vigorous toothbrushing
7 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
that dentin hypersensitivity shows a predilection for certain oral sites that may be of etiological relevance. It is not surprising incisors were mostly affected by erosion, canines and premolars were preponderantly involved in gingival recession and abrasion. Molars were observed as the most attrited teeth.
The dental management of patients where such factors, i.e., tooth wear and gingival recession are overwhelming has proven difficult for clinicians for many years, and the problem seems to be increasing because the population is retaining more natural teeth into old age.38 An increased understanding of the relationship of these entities with dentin hypersensitivity is essential to its prevention and effective management.
Conclusion Within the limitations of this study, the prevalence and distribution of the different etiological factors of dentin hypersensitivity in patients that presented with pain due to dentin hypersensitivity were obtained. Gingival recession followed by attrition were the most common etiological factors found while erosive lesions showed the most frequent association with dentin hypersensitivity. A statistically significant relationship exists between dentin hypersensitivity, tooth wear lesions, and gingival recession. There is still a need to conduct further studies to know the prevalence of tooth wear lesions and gingival recession in the general population.
Clinical Significance The etiology of dentin hypersensitivity is poorly understood. This study provides clinical evidence supporting the notion of dentin hypersensitivity being a tooth wear phenomenon. Therefore, successful preventive and management strategies for sufferers of dentin hypersensitivity must take into consideration causal factors for tooth wear and gingival recession.
The incisors and canines were predominantly affected by erosion. Smooth surfaces of anterior teeth have been shown to be particularly vulnerable to attack by acids during the consumption of acidic beverages which may cause erosion of tooth tissue.33 Most of the erosive lesions in the present study can be attributed to dietary erosion because none of the patients had a history of intrinsic acid production or occupational exposure to acids. Also, a significant relationship was observed between patients with a history of dietary acid ingestion and tooth erosion.
Some examined teeth had gingival recession, abrasions, abfractions, and attrited lesions that were not sensitive. Absi et al.34 stated not all exposed dentin is sensitive and in areas of sensitive dentin the number of tubules open at the surface was approximately eight times that of non- sensitive dentin. Furthermore, they indicated the mean diameter of open tubules in sensitive dentin was twice those as in non-sensitive dentin. They concluded the more open dentinal tubules there are on the surface and the greater the diameter, the greater the propensity for tubular fluid flow with a given stimulus.
A similar distribution of gingival recession and abrasion was found in the present study. The upper left quadrant had the highest number of teeth with gingival recession and abrasion. These conditions along with dentin hypersensitivity have been shown to be more common on the left than on the right side of the dental arches.35 Addy4 then suggested such findings showed toothbrushing is associated with dentin hypersensitivity. This is supported by the fact all the patients in this study were right handed and right handed brushers are known to brush the left buccal surfaces more effectively than on right side.32,36
Generally, low percentages of the etiological and predisposing factors were observed but their distributions agree with the summation of Addy37 in
8 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
References 1. Flynn J, Galloway R, Ochardson R. The incidence of hypersensitive teeth in the West of Scotland.
J Dent 1985; 13:230-236. 2. Dababneh RH, Khouri AT, Addy M. Dentin hypersensitivity an enigma? A review of terminology,
epidemiology, mechanisms, aetiology and management. Br Dent J 1999; 187:606-611. 3. Addy M. Tooth brushing, tooth wear and dentin hypersensitivity--are they associated? Int Dent J.
2005; 55(4 Suppl 1):261-7. 4. Addy M. Dentin hypersensitivity: new perspective on an old problem. Int Dent J 2002; 52:367-375. 5. Barbour ME, Rees GD. The role of erosion, abrasion and attrition in tooth wear. J Clin Dent. 2006;
17(4):88-93. 6. Addy M, Hunter ML. Can tooth brushing damage your health? Effects on oral and dental tissues.
Int Dent J 2003; 53(supplement 3):177–86. 7. Mair LH. Wear in dentistry – Current terminology. J Dent 1992; 20:140-144. 8. Zero DT. Etiology of dental erosion – extrinsic factors. Eur J Oral Sciences 1996; 104:162-177. 9. Scheutzel P. Etiology of dental erosion – intrinsic factors. Eur J Oral Sci 1996; 104:178-190. 10. Kelleher M, Bishop K. Tooth surface loss: an overview. Br Dent J 1999; 186:61-66. 11. Smith BGN. Tooth wear: aetiology and diagnosis. Dent Update 1989; 16:204-212. 12. Grippo JO. Abfractions: A new classification of hand tissue lesions of teeth. J Prosthetic Dent 1991;
3:14-19. 13. Braem M, Lambrechts P, Vanherle G. Stress induced cervical lesions. J Prosthet Dent 1992;
67:718-722. 14. Milosevic A. Toothwear: Aetiology and presentation. Dent Update 1998; 25:6-11. 15. Bevenius J, Lindskog S, Hultenby K. The Micromorphology in vivo of the buccocervival region of
premolar teeth in young adults. A replica study by scanning election microcopy. Acta Odont Scand 1995; 52:323-334.
16. Haywood VB. Treating sensitivity during tooth whitening. Compend Contin Educ Dent. 2005; 26(9):11-20.
17. Tredwin CJ, Naik S, Lewis NJ, Scully C. Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues. Br Dent J. 2006; 200(7):371-6.
18. Sykes LM. Dentin hypersensitivity: a review of its aetiology, pathogenesis and management. SADJ. 2007; 62(2):066-71.
19. Addy M, Absi EG, Adams D. Dentin hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentin. J Clin Periodontol 1987; 14:274-279.
20. Bradley TP, William BG, Everett BH. Examining the prevalence and characteristics of abfraction-like cervical lesions in a population of U.S. veterans. J Am Dent Assoc 2001; 132(12):1694-1701.
21. Hunter ML, Addy M, Pickles MJ, Joiner A. The role of toothpastes and toothbrushes in the aetiology of toothwear. Int Dent J 2002; 52:399-405.
22. Bergenholtz A. Mechanical cleaning in oral hygiene. In: Frandsen A, (ed) Oral hygiene. Munksgaard: Copenhagen 1976; 27-60.
23. Levitch LC, Bader JD, Shugars DA, Heymann HO. Non carious cervical lesions. J Dent 1994; 22:195-207.
24. Goutoudi P, Koidis PT, Konstantinidis A. Gingival recession: a cross-sectional clinical investigation. Eur J Prosthodont Rest Dent 1997; 5:57-61.
25. Almas K, Al-Lafi TR. The natural toothbrush. World health forum 1995; 16:206-210. 26. Oji C. Chewing sticks and oral health – review. Nigerian Dental Journal 1997; 11:27-31. 27. Kumar V, Ana JR. Prevalence and severity of tooth attrition in Nigerian rural areas. Niger Med J.
1978; 8:557-562. 28. Oginni AO, Olusile AO, Udoye CI. Non-carious cervical lesion in a Nigerian population: Abrasion or
Abfraction. Int Dent J 2003; 53:275-279. 29. Odusanya SA, Abayomi IO. Tooth attrition among rural Nigerians. Afr Dent J 1987; 1:73-78. 30. Smith BGN, Knight JK. A comparison of patterns of toothwear with the etiological factors. Br Dent J
1984; 157:16-19.
9 The Journal of Contemporary Dental Practice, Volume 9, No. 5, July 1, 2008
31. Cawson RA, Odell EW. Essentials of oral pathology and oral medicine. Churchill Livingstone 1998; 60-61.
32. Addy M, Griffiths G, Dummer P, Kingdom A, Shaw WC. The distribution of plaque and gingivitis and the influence of toothbrushing hand in a group of Southwales 11-12 year old children. J Clin Periodontol 1987; 14:564-572.
33. Eccles JD. Tooth surface loss from abrasion, attrition and erosion. Dent update 1982; 9:373-381. 34. Absi EG, Addy M, Adams D. Dentin hypersensitivity. A study of the patency of dentinal tubules in
sensitive and non-sensitive cervical dentin. J Clin Periodontol 1987; 14:280-284. 35. Addy M, Mostafa P, Newcombe RG. Dentin hypersensitivity: the distribution of recession, sensitivity
and plaque. J Dent 1987; 15:242-248. 36. Addy M, Dummer PM, Hunter ML, Kingdom A, Shaw WC. The effect of toothbrushing frequency,
toothbrushing hand, sex and social class on the incidence of plaque, gingivitis and pocketing in adolescents: a longitudinal cohort study. Community Dental Health 1990; 7:237-247.
37. Addy M. Clinical aspects of dentin hypersensitivity. Proc Finn Dent Soc 1992; 88(suppl 1):23-30. 38. Smith BGN, Knight JK. An index for measuring the wear of teeth. Br Dent J 1984; 156:435-438.
About the Authors