/home/opencode/cpanel/stomaeduj_hacked/uploads/2019/10/art-mitova-170-176.pdf PEDODONTICS STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Original Articles Nadezhda Georgieva Mitova1a , Nikolay Ishkitiev2b* 1 Department of Pediatric Dentistry, Faculty of Dental Medicine, Medical University of Sofia, Sofia, Bulgaria 2 Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria DMD, PhD, Assistant Professor a DMD, PhD, Chief Assistant Professor b ABSTRACT DOI: https://doi.org/10.25241/stomaeduj.2019.6(3).art.2 OPEN ACCESS This is an Open Access Introduction: Caries in permanent teeth most often start from the occlusal article under the CC BY-NC 4.0 license. surfaces of the first molars, soon after eruption at the age of six. At that point the Peer-Reviewed Article occlusal surfaces are at risk due to the presence of many retentive areas. Citation: Mitova NG, Ishkitiev N. Studying dentine Aim – To study the spread and characteristics of cavitated dentine caries in the first caries in the first permanent molars in children. Stoma Edu J. 2019;6(3):170-176. permanent molars after eruption. Methodology: 351 children, distributed into two groups were subjected to the Received: August 06, 2019 Revised: August 22, 2019 study: the first group - 6 to 9-year olds, and the second group - 10 to 12-year Accepted: August 27, 2019 Published: August 29, 2019 olds. The registration of the oral status was carried out with an epidemiological card for oral health assessment - brief bio, dental status and description of the *Corresponding author: Chief Assistant Professor Nikolay Ishkitiev, DMD, cavitated carious lesions in the dentine. The clinical description of the D3 carious PhD, Address: Zdrave 2 str., room 343, 1431 Sofia, Bulgaria, Tel. / Fax: +359 885 108620, lesions present was determined according to the localization of the carious lesions e-mail: ishkitiev@gmail.com. (occlusal, approximal, cervical), the color and the consistency of the carious Copyright: © 2019 the Editorial Council for the dentine, via the Bjørndal et al scale. Stomatology Edu Journal. Results: The results of this study show that children aged 6 to 12 have on average three to four carious teeth. Dentine carious lesions D3 with occlusal localization in the first permanent molars are plausibly more numerous than the carious lesions with approximal and cervical localization. In the first permanent molars, the dentine carious lesions with occlusal localization are characterized by darker colors of carious dentine and a relatively hard consistency. Conclusions: In the first permanent molars the more slowly progressing carious lesions are predominant. Keywords: Caries; Dental decay; Dentine; Occlusal surfaces; Permanent first molar. 1. Introduction of affected permanent teeth reaching six. Every Caries formation is a dynamic process of imbalances fourth 18-year-old already has one extracted tooth. in the oral environment that lead to the development Only 30% of the six-year-olds in the country are of carious lesions, on predisposed surfaces in the caries free, and with the 12-year-olds the percentage primary and permanent teeth in children [1]. The drops further down to 22% [6,7]. progression of the carious lesion may be influenced in Caries in permanent teeth most often start from the its early stages of development by modeling the oral occlusal surfaces of the first permanent molars, soon environment and remineralization [2-4]. Despite the after their eruption at the age of six. At that point indisputable successes and the increased scientific the occlusal surfaces are at risk due to the presence interest with respect to improving children’s dental of many retentive areas. The mineralization of the health, the problem of reducing the frequency and enamel at that place is not complete. Difficulty in severity of caries remains relevant [5-7]. On a world early diagnosing of the initial carious lesions present scale, 60-90% of school-age children suffer from on the occlusal surfaces of the permanent first molars caries (WHO, 2012). The disease also leads to serious and the lack of regular prophylactic examination economic consequences for society as a whole [8]. leads to the quick development of cavitated dentine According to the data from the last epidemiological lesions during the first years after eruption. This study conducted in Bulgaria in 2011, approximately requires their early inclusion in the restoration cycle, 71% of the six-year-old children in the country have and not infrequently leads to their early loss. caries, with the most frequently affected temporary Raising awareness for the spread and characteristics teeth numbering three or four. In the 12-year-olds of dental caries in the permanent first molars, group, 79% of them had caries of the permanent conducting effective prophylactics or timely teeth, with an average of three permanent teeth microinvasive treatment of already developed being affected, and in the 18 year-olds group the lesions could lead to a significant decrease of same held true for 92% of the teeth, with the number occlusal caries in children with a mixed dentition. 170 Stoma Edu J. 2019;6(3): 170-176. http://www.stomaeduj.com STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Original Articles Table 1. Visual-tactile criteria. (Bjørndal et al.) Visual criteria – dentine color Tactile criteria (with probe) - dentine consistency black Code 1 (very soft) – the probe penetrates and peels parts of it away easily; dark brown Code 2 (soft dentine) – probe can easily penetrate and exit the dentine; light brown Code 3 (moderately hard) – light resistance during probing; yellow Code 4 (hard dentine) – the probe moves over the dentine with light resistance leaving a white trail; light yellow Code 5 (hard non-carious) – soft squeaking and resistance during probing. 25 Number of dentine carios lesion 20 R e s tore d; 41.98% 15 C a rious ; 58.02% 10 5 0 6 years 7 years 8 years 9 years 10 years 11 years 12 years Age Figure 1. Ratio between carious and restored permanent first molars. Figure 2. Spread of D3 lesions in first permanent molars. t=5,00 р<0,05 Aim – To study the spread and characteristics of – enamel carious lesion visible after drying. Further cavitated dentine caries in the permanent first noted were D2, D3a, D3b and D4 carious lesions. molars, immediately after eruption. The DMFT index was used, and while registering it, Tasks for the purposes of this study, DMF(T+t) was also 1. To study the general cariousness and the relative registered, due to the fact that part of the children portion of occlusal caries in the permanent first were with a mixed dentition [9]. The fissure sealants molars in children aged 6 – 12. were included in the number of restorations. 2. To provide a clinical description of the registered The clinical description of the D3 carious lesions cavitated dentine carious lesions in the permanent present was determined according to the location first molars of the children tested. of the carious lesions (occlusal, approximal, cervical), the color and consistency of the carious dentine, via 2. Materials and Methods the Bjorndal et al scale [10]. 351 children, distributed into two groups were the The statistical processing of the data was carried out subject of the study, as follows: group one - 6 to with the statistical program SPSS (version 19, SPSS 9-year-olds; group two - 10 to 12-year-olds . We had Inc. USA). A 95% interval of plausibility (p<0.05) was received an ethical approval from KENIMUS – Etical chosen as a level of significance at which the null commission of the Medical University of Sofia – hypothesis is rejected. 24/07.12.2018. Registration of the oral status of the children was 3. Results carried out with an epidemiological card for oral 3.1. Cariousness of the children tested: health assessment, which includes a brief biography, - General cariousness dental status and description of the cavitated The results obtained in determining the cariousness carious lesions in the dentine present – D3 according – DMF(T+t) of the children tested, are presented in to the locally adopted Peneva et al. classification [9]. the following table. All surfaces of a tooth were cleaned of debris and The results show that the general cariousness plaque, the teeth were dried using an air syringe and (DMF(T+t) in all children is between three and four visually examined without magnification. If there carious teeth. A plausible decrease in cariousness were suspicious areas, then an explorer – a blunt is observed in temporary teeth, due to their probe (periodontal probe) was used to check for the replacement, while an increase in cariousness is surface texture and to remove plaque from fissures observed in permanent teeth with age (p<0.05). using a dredging motion. - Relative portion of carious and restored permanent The carious status of the children was diagnosed and first molars registered in teeth with a D1b diagnostic threshold The following diagram presents the results, obtained Stomatology Edu Journal 171 STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Original Articles Table 2. Cariousness of the children tested – DMF(T+t) as grouped by ages. DMFT DMFt DMF(T+t) Children gr. N Mean ± SD Mean ± SD Mean ± SD Ind t-test children (teeth) (teeth) (teeth) 1st gr.– 6 to 9 201 0.60 ± 0.87 3.60 ± 2.24 4.20 ± 2.31 ТT,t=-17.05 (Р=0.00) ТT,T+t=-22.78 (Р=0.00) Тt,T+t=-9.87 (Р=0.00) 2nd gr. -10 to 12 150 2.42 ± 1.76 0.99 ± 1.30 3.42 ± 1.74 ТT,t= 6.80 (Р=0.00) ТT,T+t=-9.20 (Р=0.00) Тt,T+t=-10.87 (Р=0.00) Ind T-test Т=-12.73 Р=0.00 Т= 12.7 Р=0.00 Т=-1.61 Р=0.11 Table 3. Distribution of the carious lesions in the permanent first molars. Diag. T-hold D1b D2 D3 D4 total Children group n % ± Sp n % ± Sp n % ± Sp n % ± Sp n % 1st gr–6 to 9 12 12.90±3.48 27 29.04±4.71 54 58.06±5.12 0 93 100 2 gr–10 to 12 nd 73 40.11±3.63 76 41.76±3.66 28 15.38±2.67 5 4.12±1.34 182 100 total 85 103 82 5 275 100 T test T = 5.41 T = 2.14 T = 7.39 in determining the relative portion of carious and 3.2. Clinical description of the registetred dentine restored permanent first molars of the children carious lesions (D3) in the permanent first molars of the tested. The data in the diagram show that the carious children tested. permanent first molars are plausibly predominant - Localization of the carious lesions over the restored ones in both age groups (p<0.05). The data are presented in the table 4. The data gathered in determining the severity of Between the ages of 6 and12, the D3 carious lesions the registered carious lesions in the first molars with occlusal localization in the first molars are are presented in the table 3. The data presented in 72% and are significantly more than those with the table show that in the permanent first molars approximal (14.6%) and cervical (13.4%) localization in the first age group, D1b take up only 12.9%, D2 in both age groups (p<0.05). As the children grow carious lesions are 29%, and over a half (58%) of the in age, the caries with occlusal, approximal and registered carious lesions are irreversible – D3 in the cervical localization remain within close parameters period immediately after eruption of the examined (p>0.05). The anatomical peculiarities of the perma- teeth (p<0.05). In the second age group the portion nent first molars are a primary risk factor for the onset of reversible carious lesions plausibly increases, of an occlusal caries, immediately after eruption. while the irreversible ones plausibly decrease, which They have a highly characteristic occlusal surface is probably due to the restoration of the cavitated (narrow and deep fissures), thin to non-existent lesions (p<0.05). The higher relative portion of enamel at the bottom of the fissures, significantly irreversible carious lesions in the children of the lower mineralization, insufficient self-cleaning of first age group (6-9 years) could be explained by the these surfaces, absence of established oral hygiene specificities of the carious pathology of the fissures habits and lack of motivation for early control. Early of these teeth in cases where adequate preliminary diagnostics in such cases is more difficult which prophylactics are lacking. The data gathered in this leads to the development of cavitated dentine study regarding the spread of cavitated dentine carious lesions in the molars [6,9]. carious lesions (D3) in first molars according to the - Color and consistency of the carious lesions age of the children are presented in the following The color of the carious dentine of the D3 lesions in diagram. The graph shows that the peak of registered the permanent first molars is predominantly black, D3 carious lesions in the sixth teeth of the children followed by dark brown carious dentine, while the tested can be observed as early as after the first or lowest is the number of registered D3 carious lesions second year of their eruption. A quick progression which are light brown in color (p<0.05). of the occlusal caries is present in the seven to eight The predominant darker colors in the carious year period and development of D3 carious lesions. dentine may be due to delayed pigments and this is Past eight years of age a significant decrease in the an indicator for a slower developing carious process, cases of D3 lesions is observed, probably due to an which is conducive to microinvasive treatment. The increase in the number of restored teeth. aim is to further slowdown or arrest the development 172 Stoma Edu J. 2019;6(3): 170-176. http://www.stomaeduj.com STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Original Articles Table 4. Distribution of D3 lesions in permanent first molars according to localization. total occlusal approximal cervical Children group n n % ± sp n % ± sp n % ± sp 1 gr – 6 to 9 st 54 40 74.1 ± 5.96 8 14.8 ± 4.83 6 11.1 ± 4.28 T1,2=6.08 T1,3=6.66 T2,3=0.56 2nd gr – 10 to 12 28 19 67.9 ± 8.83 4 14.3 ± 6.61 5 17.8 ± 7.24 T1,2=3.50 T1,3=3.19 T2,3=0.34 total 82 59 72.0 ± 4.96 12 14.6 ± 3.90 11 13.4 ± 3.76 T1,2=6.08 T1,3=6.66 T2,3=0.56 t2,3= 0.58 t2,3= 0.06 t2,3= 0.80 12.00% brow n; 8.54% 12.00% da rk brow n; 20.73% bla c k ; 70.73% 76.00% C ode 1 (v e ry s oft) C ode 2 (s oft dentine ) Figure 3. Color of the carious dentine in the first molars with D3 C ode 3 (m ode ra te ly ha rd) carious lesions. Pearson Chi Square = 12,468 Sig = 0,000 Figure 4. Consistency of the dentine in the D3 carious lesions of the first molars. Pearson Chi Square = 14,732 Sig = 0,000 of the dentine caries and provide conditions for index. The data are supported by high statistical activating the natural defence mechanisms of the plausibility (p<0.01). Higher values of the DMFT+t pulp-dentine complex. index are observed in the children with darker and The diagram shows that in over 3/4 of the cases the relatively hard carious dentine in the cavitated consistency of the carious dentine of the registered dentine lesions. In the first permanent molars of the D3 carious lesions is that of a moderately hard children covered in this study, the cases of relatively dentine (76%), while the remaining 1/4 of cases are hard, dry carious dentine with dark coloration are distributed equally between soft (12%) and very soft predominant. dentine (12%) (p<0.05). The data show that the consistency of the carious 4. Discussion dentine of the D3 carious lesions in permanent teeth The results of this study show that children between is predominantly code 3 – moderately hard (p<0.05). aged 6 to 12 have on average three to four carious Soft and very soft consistency (code 2 and code 1) of teeth. The general cariousness (DMFT+t) is higher the carious dentine is found in a smaller percentage between the ages of 6-9 (4.20), while in older of the cases of the registered D3 carious lesions. If children it decreases slightly (3.42). The results of we adopt the notion that the consistency of the this study show that the ratio between carious and carious dentine depends on the speed of the carious restored teeth of the children studied changes in process and is indicative of this, we could reach the the separate age groups, with the cases of carious conclusion that in the D3 carious lesions of the first teeth (D) decreasing at the expense of increasing the permanent molars, registered in this study, the caries relative proportion of restored teeth (F) as the age of with a slower development speed are predominant, the children increases. which confirms the conclusion reached regarding The data gathered in this study match that of the the color of the dentine. last national epidemiological study of the spread - The study of the interdependency of the research of dental caries in children in 2011, which showed parameters – color, consistency DMFT+t – is that in six-year-old children between three to four presented via the Pearson correlation index at a carious teeth can be found, and three carious teeth in plausibility level of p<0.05 and p<0.01. The data in 12-year-olds. The epidemiological study conducted the table show that the color of the carious dentine in the Ruse region in 2010 shows that six-year-old correlates with the consistency and the DMFT+t children have an average of six carious teeth [6,7]. Stomatology Edu Journal 173 STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Original Articles Table 5. Correlation between color, consistency and DMFT in the children studied. Pearson Correlation index indicators color const. DMFT+t color -0.767 ** -0.682** consistency -0.767** 0.673** DMFT+t -0.682** 0.673** A2008 study by M. Peneva shows that DMFT is 4.3, The rapid development of occlusal caries in the which includes only dentine carious lesions. If we dentine of newly erupted permanent molars has add enamel caries, which are reversible, the data will steered numerous researchers in the direction of show an average of seven carious teeth [11]. applying treatment methodologies that provide The first permanent molars erupt in early childhood an optimally non-invasive excavation, leading to and carry a maximal occlusal load as the main a minimal loss of hard dental structures. Careful chewing teeth. They are among the most affected excavation would allow for the preservation of form of dentine caries due to their morphological and dentine, which is partially demineralized, but with functional characteristics, which is the motivation preserved regeneration capabilities, which are highly behind this study of the spread and characteristics expressed in the permanent teeth of children [23,24]. of the dentine caries in this tooth group. This study has concluded that in the first molars, the The higher relative portion of irreversible carious dentine carious lesions with occlusal localization are lesions, established in this study, of first permanent characterized by darker colors of carious dentine molars in the children of the first age group (6-9 and a relatively hard consistency. The results of this year old) could be explained by the specificities of study confirm the idea that darker color and harder the carious pathology of the fissures of these teeth dentine consistency are probable indicators of a in cases where adequate preliminary prophylactics more slowly developing carious lesion, while lighter are lacking. The stages conducive for non-operative color and softer consistency – of a faster developing treatment in these instances pass quickly and can carious lesion [25]. easily be missed, which leads to the development of In our study we found that the newly erupted dentine caries in the permanent teeth immediately permanent first molar evince high prevalence of after their eruption, with a high risk of affecting cavitated carios lesion, which means that there is a the highly exposed pulp. As to avoiding potential significant risk of affecting the highly exposed pulp. complications in the treatment of such carious The features of the carious process in these teeth lesions, the efforts of a number of authors are makes them especially appropriate for applying the dedicated toward the development and application minimal invasive methods of treatment. The analysis of methodologies for minimally invasive operative of the results shows that in the first permanent molars treatment of dentine lesions, with the aim of the more slowly progressing carious lesions are optimally preserving the structures of the recently predominant. This circumstance has been the basis erupted permanent children’s teeth [12-15]. for trying to develop methodologies for a minimally- Similar to our study some authors have reported invasive treatment of these carious lesions, with high scores of cavitated dentine carious lesions in data being found in scientific literature in recent children in Canada (between 38% to 44.1%) and years about a number of authors working in this Thailand - in 3-year-olds [16,17]. direction [26-28]. The aim is to develop alternative The levels of cavitated dentine carious lesions methods and methodologies for a treatment which increase with age and they remain problematic in will lead to an additional slowdown and/or arrest adults [18]. The cohort study reported that over a of the carious process in the dentine and provide period of 38 years, an annual increase in number of conditions for the activation of the natural defense tooth surfaces affected by cavitated dentine carious mechanisms of the pulp-dentine complex [29,30]. lesions [19]. The results of this study show that D3 The prevalence of occlusal dentinal caries lesion carious lesions with occlusal localization in the first in the newly erupted permanent molars and their permanent molars are plausibly more numerous early inclusion in the cycle of "caries-restoration- than the carious lesions with approximal and cervical replacement of restoration" draws our attention localization in both age groups. According to a to the need of an application of new therapeutic study, the occlusal surfaces are only 6% of all dental methods of minimally-invasive treatment. The aim surfaces, while occlusal caries account for 60% of all is to ensure the preservation of integrity of the pulp caries. It is considered that this is due primarily to and apply the biological approach. the plaque retentive anatomy of these surfaces [20]. According to studies, most frequent are occlusal 5. Conclusions caries in molars, followed by approximal caries 1. Dentine carious lesions D3 with occlusal in molars, while least carious are the approximal localization in the permanent first molars are surfaces of the front teeth [21,22]. plausibly more numerous than the carious lesions 174 Stoma Edu J. 2019;6(3): 170-176. http://www.stomaeduj.com STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN with approximal and cervical localization; of the data. NI: contributed to the analysis, Original Articles 2. In the permanent first molars, the dentine carious interpretation of the data and critically revised the lesions with occlusal localization are characterized manuscript. Both authors agree to be accountable by darker colors of carious dentine and a relatively for the content of the work. hard consistency; 3. The more slowly progressing carious lesions are Acknowledgments predominant in the permanent first molars. None. Author Contributions NM: contributed to formulating the concept, protocol, data gathering, analysis and interpretation References 1. Fejerskov O. Changing paradigms in concepts on dental caries: 15. Banerjee A. Minimal intervention dentistry: part 7. Minimally consequences for oral health care. Caries Res. 2004;38(3):182-191. invasive operative caries management: rationale and techniques. [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus Br Dent J. 2013;214(3):107-111. 2. Bader JD, Shugars DA, Bonito AJ. Systematic review of selected [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus dental caries diagnostic and management methods. J Dent Educ. 16. Borsatto MC, Corona SA, Dibb RG, et al. Microleakage of a resin 2001;65(10):960-968. sealant after acid-etching, Er:YAG laser irradiation and air-abrasion [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus of pits and fissures. Clin Laser Med Surg. 2001;19(2):83-87. 3. Huysmans MC. New diagnostic approaches: promise or reality? [CrossRef ] [PubMed] Google Scholar Scopus In: Splieth CH. Revolutions in pediatric dentistry. New Malden, 17. Dennison JB, Straffon LH, Smith RC. Effectiveness of sealant Surrey (UK): Quintessence Publishing Co., Ltd; 2011. 1-10. treatment over five years in an insured population. J Am Dent 4. Lussi A, Hibst R, Paulus R. DIAGNOdent: An optical method for Assoc. 2000;131(5):597-605. caries detection. J Dent Res. 2004;83 Spec No C:C80-83. [Full text links] [PubMed] Google Scholar Scopus [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus 18. Nobre Dos SM, Rodrigues LK, Peres RC, et al. Relationships 5. Kondeva V. [Occlusal caries in childhood - epidemiological and between occlusal or free-smooth and approximal caries in mixed clinical studies.] [Bulgarian]. PhD Thesis. Plovdiv, BG: Medical dentition. Acta Odontol Scand. 2005;63(5):308-313. University of Plovdiv; 2008. [CrossRef ] [PubMed] Google Scholar Scopus 6. Peneva M, Rashkova M, Doitchinova L. [Epidemiology of 19. Balooch M, Habelitz S, Kinney JH, et al. Mechanical properties dental caries in children and adolescents in Bulgaria at different of mineralized collagen fibrils as influenced by demineralization. diagnostic threshold.] [Bulgarian]. Problems of Dental Medicine. J Struct Biol. 2008;162(3):404-410. 2007;33(2):37-46. [Full text links] [Free PMC Article] [CrossRef ] [PubMed] Google 7. Rashkova M, Ribagin L, Doganova Tsv, Aleksieva V. [Oral diseases Scholar Scopus of children from the Rousse region - epidemiological studies, 20. Banerjee A. Applications of scanning microscopy in the part of the National program for prevention of oral diseases in assessment of dentine caries and methods for its removal. PhD children aged 0-18.] [Bulgarian]. Problems of Dental Medicine. thesis. London, UK: University of London; 1999. 2011;37(2):17-28. 21. Bjørndal L, Larsen T. Changes in the cultivable flora in deep 8. Aas JA, Griffen AL, Dardis SR, et al. Bacteria of dental caries in carious lesions following a step-wise excavation procedure. Caries primary and permanent teeth in children and young adults. J Clin Res. 2000;34(6):502–508. Microbiol. 2008; 46(4):1407-1417. [Full text links] [CrossRef ] [PubMed] Google Scholar [Full text links] [Free PMC Article] [CrossRef ] [PubMed] Google 22. Li T, Zhai X, Song F, et al. Selective versus non-selective removal Scholar Scopus for dental caries: a systematic review and meta-analysis. Acta 9. Peneva M. [Dental caries in the 21st century] [Bulgarian]. Sofia, Odontol Scand. 2018;76(2):135-140. BG: East-West; 2008. [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus 10. Bjørndal L, Larsen T, Thylstrup A. A clinical and microbiological 23. Marsh PD. Are dental diseases examples of ecological study of deep carious lesions during stepwise excavation using catastrophes? Microbiology. 2003;149(Pt 2):279-294. long treatment intervals. Caries Res. 1997;31(6):411-417. [Full text links] [CrossRef ] [PubMed] Google Scholar [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus 24. Mjör IA, Ferrari M. Pulp-dentin biology in restorative 11. Peneva M. The path to transition from operative to non-operative dentistry, Part 6: Reactions to restorative materials, tooth - preventive treatment of dental caries. ScD Dissertation. Sofia, BG: restoration interfaces, and adhesive techniques. Quintessence Int. Medical University of Sofia; 2008. [Bulgarian]. 2002;33(1):35-63. 12. Bjørndal L. Buonocore Memorial Lecture. Dentin caries: Progression [PubMed] Google Scholar and clinical management. Oper Dent. 2002;27(3):211-217. 25. Hargreaves KM, Geisler T, Henry M, Wang Y. Regeneration [PubMed] Google Scholar Scopus potential of the young permanent tooth: what does the future 13. Bjørndal L. Indirect pulp therapy and stepwise excavation. hold. J Endod. 2008;34(7 Suppl):S51-S56. J Endod. 2008;34(7 Suppl):S29-S33. [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus [Full text links][CrossRef ] [PubMed] Google Scholar Scopus 26. Bjørndal L, Mjör IA. Pulp-dentin biology in restorative 14. Mickenautsch S. An introduction to minimum intervention dentistry, Part 4: Dental caries--characteristics of lesions and dentistry. Singapore Dent J. 2005; 27(1):1-6. pulpal reactions. Quintessence Int. 2001;32(9):717-736. Google Scholar Scopus [PubMed] Google Scholar Scopus Stomatology Edu Journal 175 STUDYING DENTINE CARIES IN THE FIRST PERMANENT MOLARS IN CHILDREN Nadezhda Georgieva MITOVA Original Articles DMD, PhD, Assistant Professor Department of Pediatric Dentistry Faculty of Dental Medicine Medical University of Sofia Sofia, Bulgaria CV Nadezhda Georgieva Mitova graduated from the Medical School in 2006 and Dental Medicine in 2011. Since 2012 she has been Assistant Professor in the Department of Pediatric Dentistry, Faculty of Dental Medicine, Medical University of Sofia, Sofia, Bulgaria. She has specialized in Pedodontics. Her scientific interests are focused on dental caries and profilactics of oral diseases. Questions 1. What is the most common location of caries in the permanent first molars? qa. Approximal; qb. Cervical; qc. Occlusal; qd. Other. 2. Which of the following most fully and accurately describes the causes of occlusal caries in the first permanent molars? qa. Deep and retentive fissures; unsatisfactory oral hygiene habits; qb. A thin and slightly mineralized layer of enamel; unsatisfactory oral hygiene habits; difficult diagnosis; qc. Deep and retentive fissures; a thin and slightly mineralized layer of enamel; unsatisfactory oral hygiene habits; availability of timely and adequate prevention; qd. Deep and retentive fissures; a thin and slightly mineralized layer of enamel; difficult diagnosis; unsatisfactory oral hygiene habits; lack of timely and adequate prevention. 3. What is the characteristic of carious dentine in the occlusal caries of the permanent first molars? qa. Dark and relatively hard dentine; qb. Dark and soft dentine; qc. Light and soft carious dentine; qd. Light and relatively hard dentine. 4. Which type of lesions prevails according to the speed and nature of the carious process in the occlusal caries of the permanent first molars? qa. Rapidly progressing carious lesions; qb. Slowly progressing carious lesions; qc. Both; qd. Neither. www. dentalworld.hu 176 Stoma Edu J. 2019;6(3): 170-176. http://www.stomaeduj.com