Root Caries and the Aging Population

12 Apr 2022, Fiona Collins BDS, MBA, MA, FPFA

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Root Caries and the Aging Population

Improvements in health have been achieved over several decades, including reduced partial and full edentulism1National Institute of Dental and Craniofacial Research. Tooth Loss. Reviewed July 2018. https://www.nidcr.nih.gov/research/data-statistics/tooth-loss. . In the United States, based on data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES III), 96.25% and 72.73% of individuals 20 to 64 years-of-age and 75+, respectively, had retained teeth.1National Institute of Dental and Craniofacial Research. Tooth Loss. Reviewed July 2018. https://www.nidcr.nih.gov/research/data-statistics/tooth-loss. On average, individuals in these age groups had retained 24.92 and 18.9 teeth respectively. However, one of the outcomes is that a higher percentage of middle-aged and older adults experience coronal and root caries.2Tonetti M S, Bottenberg P, Conrads G et al. Dental caries and periodontal diseases in the ageing population: call to action to protect and enhance oral health and well-being as an essential component of healthy ageing - Consensus report of group 4 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol 2017;44(Suppl 18):S135-44. In addition, the proportion of adults over age 65 is also projected to almost double globally, from 9% in 2019 to almost 17% by 2050.3United Nations. Department of Economic and Social Affairs. World Population Ageing 2019. Highlights. Available at: https://www.un.org/development/desa/pd/content/world-population-ageing-2019-highlights.

In a recent systematic review of 20 studies, the global prevalence by country for root caries was found to range from 8% to 74% in non-institutionalized older adults (community dwellers).4Chan AKY, Tamrakar M, Jiang CM et al. A Systematic Review on Caries Status of Older Adults. Int J Environ Res Public Health 2021;18(20):10662. doi: 10.3390/ijerph182010662. The lowest and highest prevalence were found for Finland and Brazil, respectively. In comparison, the prevalence for dental caries overall ranged from 25% to 99%. Based on data from NHANES III1National Institute of Dental and Craniofacial Research. Tooth Loss. Reviewed July 2018. https://www.nidcr.nih.gov/research/data-statistics/tooth-loss. , the prevalence of untreated and restored root caries in the 75+ age group was estimated at 42% for the United States. One study reported a root caries prevalence of >70% in 2010.5Ahluwalia KP, Cheng B, Josephs PK, et al. Oral disease experience of older adults seeking oral health services. Gerodontology 2010;27:96-103. Lastly, in a recent review of untreated caries in adults in the United States from 2017 to 2020, the prevalence of untreated root caries and coronal caries was estimated at 10% and 17.9%, respectively.6Bashir NZ. Update on the prevalence of untreated caries in the US adult population, 2017-2020. J Am Dent Assoc 2022;153(4):300-308. doi: 10.1016/j.adaj.2021.09.004.

Tooth retention and demographic shifts are resulting in an increasing burden for root caries.

Risk Factors/Indicators for Root Caries

Risk factors for both root caries and coronal caries include poor oral hygiene, frequent consumption of fermentable carbohydrates and the presence of cariogenic bacteria.7Pitts NB, Zero DT, Marsh PD et al. Dental caries. Nat Rev Dis Primers 2017;25(3):17030. ,8Bibby BG, Krobicka A. An in vitro method for making repeated pH measurements on human dental plaque. J Dent Res 1984;63:906-9. Other risk factors include reduced/absent salivary flow (which reduces buffering capacity), a familial history of dental caries, lower socioeconomic status, increasing age, tobacco use, substance abuse, proximity to partial dentures, low levels of fluoride exposure and genetics.9American Dental Association. Caries Risk Assessment Form (Age 0-6). Available at: https://www.ada.org/~/media/ADA/Member%20Center/FIles/topics_caries_under6.pdf. ,10American Dental Association. Caries Risk Assessment Form (Age >6). Available at: http://www.ada.org/~/media/ADA/Science%20and%20Research/Files/topic_caries_over6.ashx. ,11Opal S, Garg S, Jain J, Walia I. Genetic factors affecting dental caries risk. Aust Dent J 2015;60:2-11.,12Tan HP, Lo ECM. Risk indicators for root caries in institutionalized elders. Comm Dent Oral Epidemiol 2014;42(5):435-440.,13Zhang J, Sardana D, Wong MCM et al. Factors Associated with Dental Root Caries: A Systematic Review. JDR Clin Trans Res 2020;5(1):13-29. doi:10.1177/2380084419849045.

Genetics may impact host susceptibility by influencing tooth structure, salivary status, taste perception, and the host response to cariogenic bacteria.11Opal S, Garg S, Jain J, Walia I. Genetic factors affecting dental caries risk. Aust Dent J 2015;60:2-11.,14Shuler CF. Inherited risks for susceptibility to dental caries. J Dent Educ 2001;65(10):1038-45.,15Bretz WA, Corby PM, Melo MR et al. Heritability estimates for dental caries and sucrose sweetness preference. Arch Oral Biol 2006;51(12):1156-60.,16Nibali L, Di Iorio A, Tu YK, Vieira A. Host genetics role in the pathogenesis of periodontal disease and caries. J Clin Periodontol 2017;44(Suppl 18):S52-S78. doi: 10.1111/jcpe.12639. ,17Lips A, Antunes LS, Pintor AVB et al. Salivary protein polymorphisms and risk of dental caries: a systematic review. Braz Oral Res 2017;31:e41.,18Gati D, Vieira AR. Elderly at greater risk for root caries: a look at the multifactorial risks with emphasis on genetics susceptibility. Int J Dent 2011;2011:647168. doi: 10.1155/2011/647168. A low-pH environment fosters a shift in the biofilm with more acidogenic and aciduric bacteria, increasing caries risk. It is also suggested that the oral microbial community favoring dental caries may be associated with absence of host genome adaptation.19Gomez A, Espinoza JL, Harkins DM et al. Host genetic control of the oral microbiome in health and disease. Cell Host Microbe 2017;22:269-78,e263. In a systematic review of thirteen studies, factors associated with root caries included the presence of root caries at baseline, plaque index and the number of teeth present.20Ritter AV, Shugars DA, Bader JD. Root caries risk indicators: a systematic review of risk models. Community Dent Oral Epidemiol 2010;38(5):383-97. doi: 10.1111/j.1600-0528.2010.00551.x.

Exposed root surfaces, which can be the result of gingival recession, periodontal disease, and periodontal treatment, increase risk specifically for root caries.21Hayes M, Da Mata C, Cole M et al. Risk indicators associated with root caries in independently living older adults. J Dent 2016;51:8-14. doi: 10.1016/j.jdent.2016.05.006. The cementum covering the root surface dentin is also thin and readily lost, exposing the dentin. In one study with patients receiving periodontal maintenance, it was concluded that root caries is a complication of periodontal therapy.22Reiker J, van der Velden U, Barendregt DS, Loos BG. Wortelcariës bij patiënten in parodontale nazorg. Prevalentie en risico-indicatoren [Root caries in patients in periodontal follow-up care. Prevalence and risk factors]. Ned Tijdschr Tandheelkd 2000;107(10):402-5. Dutch. Tobacco use increases caries risk for root and coronal surfaces, and chew tobacco plays a role for coronal and root caries due to its sugar content. However, chew tobacco is also a cause of gingival recession where the wad is held, thereby adding a risk factor for root caries.21Hayes M, Da Mata C, Cole M et al. Risk indicators associated with root caries in independently living older adults. J Dent 2016;51:8-14. doi: 10.1016/j.jdent.2016.05.006. ,23Tomar SL, Winn DM. Chewing tobacco use and dental caries among US men. J Am Dent Assoc 1999;130:1601-10. It is also hypothesized that use of chew tobacco may enhance collagenase activity.

In one study with patients receiving periodontal maintenance, it was concluded that root caries is a complication of periodontal therapy.

Risk Assessment

While numerous childhood and adult caries risk assessment tools are available, these are not specific to risk assessment for root caries.24Doméjean S, Banerjee A. Assessing the Risk of Developing Carious Lesions in Root Surfaces. Monographs Oral Sci 2017;26:55-62. DOI: 10.1159/000479343. In addition, standard caries risk assessment tools do not address periodontal disease as a risk factor and the combined impact along with caries and factors related to increased age.25Gavriilidou NN, Belibasakis GN. Root caries: the intersection between periodontal disease and dental caries in the course of ageing. Br Dent J 2019;227(12):1063-7. doi: 10.1038/s41415-019-0973-4. There are no validated tools for root caries risk assessment.26Twetman S, Banerjee A. (2020) Caries Risk Assessment. In: Chapple I, Papapanou P. (eds) Risk Assessment in Oral Health. Springer, Cham.

Differentiating Features and Diagnosis

The presence of cariogenic bacteria and fermentable carbohydrates are prerequisites for caries, resulting in bacterial acid production. Initiation of root and coronal caries lesions depends on the balance between destructive and protective factors, and whether demineralization outpaces remineralization. The critical pH for demineralization of enamel is 5.5. In contrast, since dentin has a lower inorganic content, the critical pH for demineralization is 6 to 6.8 which means that less of a decrease is needed after bacterial acid production for demineralization to occur. An acidic environment also activates matrix metalloproteinases and cathepsins present, which are involved in collagen degradation in demineralized dentin.27Takahashi N, Nyvad B. Ecological Hypothesis of Dentin and Root Caries. Caries Res 2016;50(4):422-31. doi:10.1159/000447309. These factors enhance the rapidity with which root caries lesions progress compared to incipient coronal lesions.28Tan H, Richards L, Walsh T et al. Interventions for managing root caries. Cochrane Database Syst Rev 2017;2017(8):CD012750. doi:10.1002/14651858.CD012750 (Figure 1) Early root caries detection relies on visual-tactile examination, with dentin softening and a shift to a slightly brown color evident early in lesion development.29Fee PA, Macey R, Walsh T et al. Tests to detect and inform the diagnosis of root caries. Cochrane Database Syst Rev 2020;12(12):CD013806. doi: 10.1002/14651858.CD013806. In a recent Cochrane review on detection and diagnosis of root caries, the diagnostic accuracy of radiographs, laser fluorescence, electronic caries monitor (ECM) and transillumination were also assessed either as a stand-alone adjunct or in combination.29Fee PA, Macey R, Walsh T et al. Tests to detect and inform the diagnosis of root caries. Cochrane Database Syst Rev 2020;12(12):CD013806. doi: 10.1002/14651858.CD013806. Sensitivity and specificity varied considerably and there was a paucity of data available. No conclusions were possible on any potential benefit.

Figure 1. Features and contrasts of coronal caries and root caries

Coronal Caries Root Caries
Many risk factors in common with root caries. Exposed root surfaces are a risk factor specific to root caries.
Validated risk assessment tools. No validated risk assessment tools.
Critical pH for demineralization while in enamel is 5.5. Critical pH for dentin is higher at a pH ranging from 6.0 to 6.8.
No degradation of enamel by MMPs/cathepsins, later in dentin. Collagen degradation in dentin by MMPs and cathepsins.
Slower progression of incipient lesions in enamel. Faster progression of incipient lesions in dentin.
Visual-tactile examination and adjunctive use of radiographs, other technologies. Relies on visual-tactile examination only.

Root Caries Prevention and Management

For both root caries prevention and management, patients should be educated on diet and on minimizing intake of free sugars and other fermentable carbohydrates. Regular instruction and feedback on twice-daily thorough oral hygiene is also needed.

Preventing root caries
Clinical recommendations published by the American Dental Association (2013) for the prevention of root caries include application of 5% sodium fluoride varnish or 1.23% APF gel at least every three to six months.30Weyant RJ, Tracy SL, Anselmo T et al. Topical fluoride for caries prevention. J Am Dent Assoc 2013;144(11):1279-91. doi.org/10.14219/jada.archive.2013.0057 Home use of a 1.1% sodium fluoride gel or paste twice daily, or 0.2% sodium fluoride mouth rinse weekly, is also recommended. In a systemic review and meta-analysis, reductions in root caries lesions were found for chlorhexidine varnish and silver diamine fluoride (SDF).31Hayes, M. Topical agents for root caries prevention. Evid Based Dent 2015;16:10-11. https://doi.org/10.1038/sj.ebd.6401074 It was noted that there were few trials and that these were at high risk for bias. Adjunctive interventions such as xylitol gum/lozenges, antimicrobial rinses and calcium and phosphate may also be considered provided there are no contraindications. In a three-year double-blind multi-center randomized clinical trial (the Xylitol for Adult Caries Trial) with participants ages 21 to 80 years, adjunctive use of xylitol lozenges in adults was found to reduce root caries lesions by 40%, while for coronal surfaces no reductions in caries lesions were found.32Ritter AV, Bader JD, Leo MC et al. Tooth-surface-specific effects of xylitol: randomized trial results. J Dent Res 2013;92:512-7.

Clinical recommendations for the prevention of root caries include application of 5% sodium fluoride varnish or 1.23% APF gel at least every three to six months.

Interventions for non-cavitated and cavitated root caries lesions

For arrestment/reversal of root caries, in the United States use of 5,000 ppm fluoride toothpaste/gel is recommended for non-cavitated and cavitated lesions.33Slayton RL, Urquhart O, Araujo MWB et al. Evidence-based clinical practice guideline on nonrestorative treatments for carious lesions. A report from the American Dental Association. J Am Dent Assoc 2018;149(10):P837-49.E10. doi.org/10.1016/j.adaj.2018.07.002 Lower-priority alternatives, in decreasing order, include 5% sodium fluoride varnish (every 3-6 months), 38% SDF + potassium iodide annually, 38% SDF annually, and 1% chlorhexidine+1% thymol varnish every 3-6 months. With respect to SDF, the application of potassium iodide as a separate step minimizes the stain associated with use of SDF. Prioritization was based on efficacy, resource use, feasibility and patient values and preferences.

Noninvasive Interventions for Root Caries Lesions
Twice-daily use of 5000 ppm fluoride toothpaste/gel
Descending priority
5% sodium fluoride varnish every 3 to 6 months
38% SDF + potassium iodide annually
38% SDF annually
1% chlorhexidine + 1% thymol varnish every 3 to 6 months

In a recent European systematic review of thirteen studies, it was concluded that high-fluoride toothpastes, 38% SDF and toothpastes containing 1.5% arginine were effective for root caries management.34Castelo R, Attik N, Catirse ABCEB et al. Is there a preferable management for root caries in middle-aged and older adults? A systematic review. Br Dent J. 2021 May 27. doi: 10.1038/s41415-021-3003-2. SDF was found to be the most effective. In another systematic review and meta-analysis of 34 studies with more than 10,000 patients, reductions in root caries risk were 51% and 21%, respectively, for high-level fluoride dentifrices containing 5,000 ppm and a toothpaste containing 1.5% arginine plus 1,450 ppm fluoride.35Wierichs RJ, Meyer-Lueckel H. Systematic review on noninvasive treatment of root caries lesions. J Dent Res 2015;94(2):261-71. doi: 10.1177/0022034514557330. Lastly, in an individual study comparing 1450 ppm fluoride dentifrice with or without the addition of 1.5% arginine, root caries arrestment/reversal at 6 months was significantly greater for the arginine-containing dentifrice.36Souza ML, Cury JA, Tenuta LM et al. Comparing the efficacy of a dentifrice containing 1.5% arginine and 1450 ppm fluoride to a dentifrice containing 1450 ppm fluoride alone in the management of primary root caries. J Dent 2013;41(Suppl 2):S35-41. doi: 10.1016/j.jdent.2010.04.006.

In a systematic review, reductions in root caries risk were 51% and 21%, respectively, for 5,000 ppm fluoride dentifrice and dentifrice containing 1.5% arginine plus 1,450 ppm fluoride.

Minimally invasive and invasive interventions
As part of a recent review (2019) systematic reviews and meta-analyses were conducted to evaluate root caries interventions, where possible.37Meyer-Lueckel H, Machiulskiene V, Giacaman RA. How to Intervene in the Root Caries Process? Systematic Review and Meta-Analyses. Caries Res 2019;53(6):599-608. doi: 10.1159/000501588. With respect to minimally invasive techniques, outcomes could not be evaluated for lesion exposure as there were no controlled trials, and for sealants the paucity of studies and conclusions precluded any recommendations. Restorative options include atraumatic restorative treatment (ART) typically using glass ionomer cements (GIC) and conventional restorative care (CRC). In a comparison across three studies, a marginally higher failure rate was found for ART than for CRC. However, the low level of data precluded supporting either ART or CRC.38Göstemeyer G, da Mata C, McKenna G, Schwendicke F. Atraumatic vs conventional restorative treatment for root caries lesions in older patients: Meta- and trial sequential analysis. Gerodontology 2019;36(3):285-293. doi: 10.1111/ger.12409. In another review, one study reported a statistically significantly higher success rate for CRC compared to ART, while for four other clinical studies success rates were similar for both treatment methods.39Tonprasong W, Inokoshi M, Shimizubata M et al. Impact of direct restorative dental materials on surface root caries treatment. Evidence based and current materials development: A systematic review. Jpn Dent Sci Rev 2022;58:13-30. doi: 10.1016/j.jdsr.2021.11.004. Epub 2021 Dec 29.

Outcomes could not be evaluated for lesion exposure in a systematic review as there were no controlled trials, and for sealants the paucity of studies and conclusions precluded any recommendations.

Options for CRC include GIC, resin-modified glass ionomer cement (RMGIC), composite resin (CR), or compomers (CMP). Amalgam is a potential option, however this would depend on tooth location and visibility of the area, given the resulting unesthetic appearance. In one meta-analysis, failure rates were observed to be higher for GIC and RMGIC compared to CR.37Meyer-Lueckel H, Machiulskiene V, Giacaman RA. How to Intervene in the Root Caries Process? Systematic Review and Meta-Analyses. Caries Res 2019;53(6):599-608. doi: 10.1159/000501588. In contrast, in a systematic review conducted in 2022 to evaluate outcomes for the use of GIC, RMGIC and CR in in vitro and clinical studies, it was not possible to draw conclusions on the most suitable material for root caries lesions.39Tonprasong W, Inokoshi M, Shimizubata M et al. Impact of direct restorative dental materials on surface root caries treatment. Evidence based and current materials development: A systematic review. Jpn Dent Sci Rev 2022;58:13-30. doi: 10.1016/j.jdsr.2021.11.004. Epub 2021 Dec 29. Annual failure rates have been reported that vary significantly.40Fernandes MS, Castelo PM, Chaves GN et al. Relationship between polypharmacy, xerostomia, gustatory sensitivity, and swallowing complaints in the elderly: A multidisciplinary approach. J Texture Stud 2021;52(2):187-196. doi: 10.1111/jtxs.12573. Reasons for failure include marginal defects, recurrent caries and loss of retention.37Meyer-Lueckel H, Machiulskiene V, Giacaman RA. How to Intervene in the Root Caries Process? Systematic Review and Meta-Analyses. Caries Res 2019;53(6):599-608. doi: 10.1159/000501588. Invasive procedures for root caries can by nature be challenging due to location and moisture control.

Restorative options for root caries lesions
Atraumatic restorative treatment
Glass ionomer cements
Resin-modified glass ionomer cements
Compomers
Other cements
Amalgam

Recently introduced restorative materials include the use of pre-reacted GIC, fluoroaluminosilicate glass, and nanoparticles of amorphous calcium phosphate. In addition, the incorporation of silver nanoparticles, 12-methacryloyloxydodecyl pyridinium bromide (MDPB) and other compounds are being investigated, as well as the use of biological membranes.39Tonprasong W, Inokoshi M, Shimizubata M et al. Impact of direct restorative dental materials on surface root caries treatment. Evidence based and current materials development: A systematic review. Jpn Dent Sci Rev 2022;58:13-30. doi: 10.1016/j.jdsr.2021.11.004. Epub 2021 Dec 29. An in vitro study suggests that the incorporation of MDPB into adhesive may inhibit artificial root caries, and in restorative material may be protective against recurrent caries and collagen degradation by MMP and cathepsins.39Tonprasong W, Inokoshi M, Shimizubata M et al. Impact of direct restorative dental materials on surface root caries treatment. Evidence based and current materials development: A systematic review. Jpn Dent Sci Rev 2022;58:13-30. doi: 10.1016/j.jdsr.2021.11.004. Epub 2021 Dec 29.

Considerations

Tooth retention improves quality of life, helping older individuals maintain a nutritious diet and contributing to the prevention of physical decline.2Tonetti M S, Bottenberg P, Conrads G et al. Dental caries and periodontal diseases in the ageing population: call to action to protect and enhance oral health and well-being as an essential component of healthy ageing - Consensus report of group 4 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol 2017;44(Suppl 18):S135-44. However, the burden for root caries is increasing due to tooth retention, increased longevity and the demographic shift that continues. Dental professionals can therefore expect to see more patients with root caries and more elderly patients. Older patients experience greater burdens for systemic diseases and conditions and associated treatments, and an increasing reliance on single/multiple medications - many of which cause dry mouth as a side effect. Furthermore, polypharmacy is strongly associated with dry mouth complaints and lower salivary flow rates,40Fernandes MS, Castelo PM, Chaves GN et al. Relationship between polypharmacy, xerostomia, gustatory sensitivity, and swallowing complaints in the elderly: A multidisciplinary approach. J Texture Stud 2021;52(2):187-196. doi: 10.1111/jtxs.12573. further increasing risk for coronal and root caries. In addition, the prevalence of moderate to severe periodontal disease, itself a risk factor, is greatest in the over-65 age group.41Hayes M, Brady P, Burke FM, Allen PF. Failure rates of class V restorations in the management of root caries in adults - a systematic review. Gerodontology. 2016 Sep;33((3)):299–307. Physical and cognitive decline also play a role, with some older patients less able to perform proper oral hygiene which is already difficult in hard-to-reach root surface areas.

The burden for root caries is increasing due to tooth retention, increased longevity and the demographic shift that continues.

Conclusions

Root caries is a significant oral health issue. However, there remain uncertainties regarding risk assessment, the potential value of diagnostic adjuncts, prevention and therapies and it was noted in reviews that studies were heterogeneous.30Weyant RJ, Tracy SL, Anselmo T et al. Topical fluoride for caries prevention. J Am Dent Assoc 2013;144(11):1279-91. doi.org/10.14219/jada.archive.2013.0057,35Wierichs RJ, Meyer-Lueckel H. Systematic review on noninvasive treatment of root caries lesions. J Dent Res 2015;94(2):261-71. doi: 10.1177/0022034514557330.,37Meyer-Lueckel H, Machiulskiene V, Giacaman RA. How to Intervene in the Root Caries Process? Systematic Review and Meta-Analyses. Caries Res 2019;53(6):599-608. doi: 10.1159/000501588.,41Hayes M, Brady P, Burke FM, Allen PF. Failure rates of class V restorations in the management of root caries in adults - a systematic review. Gerodontology. 2016 Sep;33((3)):299–307. Robust clinical trials are needed to further inform the best approaches for the evidence-based management of root caries. Current cornerstones for the prevention of root caries include oral hygiene instruction, dietary advice, and fluoride therapies. Patient care for individuals at risk for root caries should prioritize prevention, and the earliest possible noninvasive management to treat existing root caries lesions, using current recommendations and guidelines.

References

  • 1.National Institute of Dental and Craniofacial Research. Tooth Loss. Reviewed July 2018. https://www.nidcr.nih.gov/research/data-statistics/tooth-loss.
  • 2.Tonetti M S, Bottenberg P, Conrads G et al. Dental caries and periodontal diseases in the ageing population: call to action to protect and enhance oral health and well-being as an essential component of healthy ageing - Consensus report of group 4 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol 2017;44(Suppl 18):S135-44.
  • 3.United Nations. Department of Economic and Social Affairs. World Population Ageing 2019. Highlights. Available at: https://www.un.org/development/desa/pd/content/world-population-ageing-2019-highlights.
  • 4.Chan AKY, Tamrakar M, Jiang CM et al. A Systematic Review on Caries Status of Older Adults. Int J Environ Res Public Health 2021;18(20):10662. doi: 10.3390/ijerph182010662.
  • 5.Ahluwalia KP, Cheng B, Josephs PK, et al. Oral disease experience of older adults seeking oral health services. Gerodontology 2010;27:96-103.
  • 6.Bashir NZ. Update on the prevalence of untreated caries in the US adult population, 2017-2020. J Am Dent Assoc 2022;153(4):300-308. doi: 10.1016/j.adaj.2021.09.004.
  • 7.Pitts NB, Zero DT, Marsh PD et al. Dental caries. Nat Rev Dis Primers 2017;25(3):17030.
  • 8.Bibby BG, Krobicka A. An in vitro method for making repeated pH measurements on human dental plaque. J Dent Res 1984;63:906-9.
  • 9.American Dental Association. Caries Risk Assessment Form (Age 0-6). Available at: https://www.ada.org/~/media/ADA/Member%20Center/FIles/topics_caries_under6.pdf.
  • 10.American Dental Association. Caries Risk Assessment Form (Age >6). Available at: http://www.ada.org/~/media/ADA/Science%20and%20Research/Files/topic_caries_over6.ashx.
  • 11.Opal S, Garg S, Jain J, Walia I. Genetic factors affecting dental caries risk. Aust Dent J 2015;60:2-11.
  • 12.Tan HP, Lo ECM. Risk indicators for root caries in institutionalized elders. Comm Dent Oral Epidemiol 2014;42(5):435-440.
  • 13.Zhang J, Sardana D, Wong MCM et al. Factors Associated with Dental Root Caries: A Systematic Review. JDR Clin Trans Res 2020;5(1):13-29. doi:10.1177/2380084419849045.
  • 14.Shuler CF. Inherited risks for susceptibility to dental caries. J Dent Educ 2001;65(10):1038-45.
  • 15.Bretz WA, Corby PM, Melo MR et al. Heritability estimates for dental caries and sucrose sweetness preference. Arch Oral Biol 2006;51(12):1156-60.
  • 16.Nibali L, Di Iorio A, Tu YK, Vieira A. Host genetics role in the pathogenesis of periodontal disease and caries. J Clin Periodontol 2017;44(Suppl 18):S52-S78. doi: 10.1111/jcpe.12639.
  • 17.Lips A, Antunes LS, Pintor AVB et al. Salivary protein polymorphisms and risk of dental caries: a systematic review. Braz Oral Res 2017;31:e41.
  • 18.Gati D, Vieira AR. Elderly at greater risk for root caries: a look at the multifactorial risks with emphasis on genetics susceptibility. Int J Dent 2011;2011:647168. doi: 10.1155/2011/647168.
  • 19.Gomez A, Espinoza JL, Harkins DM et al. Host genetic control of the oral microbiome in health and disease. Cell Host Microbe 2017;22:269-78,e263.
  • 20.Ritter AV, Shugars DA, Bader JD. Root caries risk indicators: a systematic review of risk models. Community Dent Oral Epidemiol 2010;38(5):383-97. doi: 10.1111/j.1600-0528.2010.00551.x.
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  • 22.Reiker J, van der Velden U, Barendregt DS, Loos BG. Wortelcariës bij patiënten in parodontale nazorg. Prevalentie en risico-indicatoren [Root caries in patients in periodontal follow-up care. Prevalence and risk factors]. Ned Tijdschr Tandheelkd 2000;107(10):402-5. Dutch.
  • 23.Tomar SL, Winn DM. Chewing tobacco use and dental caries among US men. J Am Dent Assoc 1999;130:1601-10.
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  • 28.Tan H, Richards L, Walsh T et al. Interventions for managing root caries. Cochrane Database Syst Rev 2017;2017(8):CD012750. doi:10.1002/14651858.CD012750
  • 29.Fee PA, Macey R, Walsh T et al. Tests to detect and inform the diagnosis of root caries. Cochrane Database Syst Rev 2020;12(12):CD013806. doi: 10.1002/14651858.CD013806.
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  • 31.Hayes, M. Topical agents for root caries prevention. Evid Based Dent 2015;16:10-11. https://doi.org/10.1038/sj.ebd.6401074
  • 32.Ritter AV, Bader JD, Leo MC et al. Tooth-surface-specific effects of xylitol: randomized trial results. J Dent Res 2013;92:512-7.
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