|Year : 2016 | Volume
| Issue : 4 | Page : 370-376
Cariogenic microbiota of children under chemotherapy: A pilot study
Luiz Evaristo Ricci Volpato1, Annelyze Podolan Kloster2, Lenieser Fajardo Nunes1, Fabio Luis Miranda Pedro1, Alvaro Henrique Borges1
1 Master's Program in Integrated Dental Scieces, Cuiaba, Brazil
2 Department of Pediatric Dentistry, CuiabŠ Dental School, University of CuiabŠ, Cuiaba, Brazil
|Date of Web Publication||29-Sep-2016|
Luiz Evaristo Ricci Volpato
Estev„o de MendonÁa St. CuiabŠ, MT, ZIP: 78032-085
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Aim: To analyze the cariogenic microbiota of children who are under antineoplastic therapy. Methods: Twenty-seven patients undergoing cancer treatment in the Pediatric Unit of Mato Grosso Cancer Hospital were selected. The inclusion criteria of volunteers were being under chemotherapy in the saliva collection period, age between 2 and 18 years, collaborate with the protocol for clinical examination and saliva collection, and responsible have given their written consent. For the realization of lactobacilli and Streptococcus mutans count in the patients' saliva, respectively, Dentalcult I and II (LaborClin; ) kits were used. Statistical Analysis: Kruskal-Wallis and Fisher's exact tests were used to assess the association of the variables age group, prevalence of lactobacilli and S. mutans, diagnosis of patients, presence and level of decay of patients defined by decayed, filled, and missing teeth (DMFT)/dmft indexes with a significance level of 5%. Results: The group of patients consisted of 27 children, 15 males, and 12 females; 44% were aged between 6 and 10 years; 61% had present or past history of caries (dmft/DMFT >0); 48% had low value for Dentalcult I; 59% presented value grade 0 to Dentalcult II; and 63% were diagnosed with acute lymphoid leukemia. Conclusion: There was a high prevalence of dental caries in the study population but low rates of S. mutans and lactobacilli in the saliva of the children. Lactobacilli rate was significantly associated with caries index scores, and the prevalence of caries was directly associated with the age group of the children.
Keywords: Cancer, dental caries, microbiological analysis, oral health, oral manifestations
|How to cite this article:|
Volpato LE, Kloster AP, Nunes LF, Pedro FL, Borges AH. Cariogenic microbiota of children under chemotherapy: A pilot study. J Indian Soc Pedod Prev Dent 2016;34:370-6
|How to cite this URL:|
Volpato LE, Kloster AP, Nunes LF, Pedro FL, Borges AH. Cariogenic microbiota of children under chemotherapy: A pilot study. J Indian Soc Pedod Prev Dent [serial online] 2016 [cited 2019 Dec 6];34:370-6. Available from: http://www.jisppd.com/text.asp?2016/34/4/370/191423
| Introduction|| |
Treatment of childhood cancer has shown promising results in the last four decades. Currently, children with the disease can be cured from early diagnosis and specialized treatment.  The treatment can be accomplished by surgery, chemotherapy, and radiotherapy, simultaneously or in isolation, depending on the nature and extent of cancer. ,
However, there are many adverse side effects from the anticancer therapies. In the oral cavity, mucositis, xerostomia, dysphagia, taste alterations, candidiasis, gingival bleeding, herpes labialis, pain, and trismus are commonly observed. , Although tooth decay is not an alteration directly derived from anticancer therapies, its expression can be indirectly influenced by the other alterations. 
Thus, the dental evaluation prior to the beginning of the cancer treatment is very important. The entire oral cavity should be examined to eliminate existing conditions which may cause complications to the child such as extensive carious lesions, periapical pathologies, advanced periodontal disease, and teeth with an indication for extraction.  It is also important that during and after cancer treatment, the patient's oral health is monitored as the anticancer treatment decreases immune capacity, impairing the healing process, facilitating the occurrence of bleeding, and leaving patients vulnerable to infections and inflammations. 
Since much of the oral problems, especially in children, are due to tooth decay and as that is closely related to specific bacterial groups,  the present pilot study aimed to analyze the cariogenic microbiota of children under antineoplastic therapy.
| Methods|| |
In the Pediatric Unit of the Mato Grosso Cancer Hospital, 27 patients undergoing cancer treatment were selected by convenience. The inclusion criteria were as follows:
- Age between 2 and 18 years
- Be under chemotherapy
- Responsible have given their written consent.
Data on patients' age, sex, and diagnosis were taken from their medical records.
The clinical examination of the patients was executed by a single professional robed with disposable gloves, face mask, and wooden spatula under fluorescent light. The decayed, filled, and missing teeth (DMFT)/dmft indexes, respectively, were used to assess the number of decayed, missing, and filled permanent and primary teeth.
After examination of the dental condition of the patients, saliva was collected with disposable pipettes provided in the Dentalcult (LaborClin® , Pinhais, PR, Brazil) kits. Both clinical examination and saliva collection were performed at the hospital in a room attached to the waiting room where children and their parents waited to start chemotherapy.
It was considered in this study as cariogenic microbiota the occurrence of lactobacilli and mutans streptococci, as well as their quantity in the patients' saliva. , To perform the lactobacilli and Streptococcus mutans counts, the Dentalcult I and II kits were used. The kits comprise Rogosa agar plates for the development of lactobacilli and modified mitis salivarius agar plates, which allows the isolation of S. mutans by the use of bacitracin and sucrose concentration of 20%, having the ability to inhibit the growth of various bacteria in the local microflora. In the S. mutans culture medium, CO 2 tablets were used to allow the specific bacteria to grow, if they were present in the samples. The tubes were properly identified and incubated in an incubator at 35°C for 48 h and after this period; the laminas were read and graded according to the template provided by the manufacturer.
According to the manufacturer, the result of lactobacilli count (in colony forming units/ml of saliva - CFU/ml) can be interpreted as a risk factor: Below 10 4 CFU/ml: Low risk; between 10 4 and 10 5 CFU/ml: Moderate risk and above 10 5 CFU/ml: High risk. Moreover, the count of S. mutans (also in CFU/ml of saliva) as the potential cariogenic factor: Below 10 4 CFU/ml: Grade 0; between 10 4 and 10 5 CFU/ml: Grade I; between 10 5 and 10 6 CFU/ml: Grade II and above 10 6 : Grade III.
Fisher's exact test was used to assess whether the age group, the prevalence of lactobacilli and S. mutans, and diagnosis of the patients had some association with the presence of caries, as well as the age and diagnosis, have some association with the prevalence of lactobacilli and S. mutans. Kruskal-Wallis test was used to evaluate if the age group and the prevalence of lactobacilli and S. mutans and diagnosis of patients were associated with the level of decay of patients defined by DMFT/dmft indexes. This study considered a significance level of 5% for all statistical analyses.
The research project was approved by the Research Ethics Committee of the University of Cuiabα (Protocol 0307-124/CEP/UNIC) and followed the ethical standards of the Helsinki Declaration of 1975 as revised in 2000.
| Results|| |
The group of examined patients consisted of 27 children, 15 males, and 12 females; 44% were between 6 and 10 years, 61% had past or present history of caries (dmft or DMFT >0), 48% had low prevalence of lactobacilli, 59% had grade 0 value for the occurrence of S. mutans, and 63% were diagnosed with acute lymphoid leukemia (ALL) [Table 1].
|Table 1: Absolute and relative distribution of patients according to age, diagnosis, presence or absence of dental caries and the prevalence of lactobacilli and S. mutans|
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Regarding the DMFT/dmft indexes, there was an average of 2.52, with a median of 3 standard deviation of 2.54, minimum value of 0, and a maximum of 8.
In assessing whether the age, lactobacilli, and S. mutans occurrence scores and diagnosis of patients were associated with the presence of caries, a statistically significant association was found only for the age group (P = 0.0290). The number of lactobacilli and S. mutans colony forming units and patients' diagnosis was not associated with the presence of caries [Table 2].
|Table 2: Analysis of the association between the presence of dental caries and the patients' age group, diagnosis and number of lactobacilli and S. mutans colony forming units using Fisher's exact test|
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Then, the association between age group, the occurrence of lactobacilli and S. mutans, and patients' diagnosis and the DMFT/dmft scores were statistically analyzed using the Kruskal-Wallis test. Statistically significant association was found between the lactobacilli quantity and the DMFT/dmft scores (P = 0.0056). Statistically significant association was not detected between caries score and age group, the occurrence of S. mutans and diagnosis of the patient [Table 3].
|Table 3: Mean, median, standard deviation, minimum and maximum dental caries scores (DMFT/dmft) by age group, and number of lactobacilli and S. mutans colony forming units, diagnosis, followed by P value of the Kruskal - Wallis test|
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Finally, the Fisher's exact test was used to assess if the age group and the diagnostic were associated with the occurrence of lactobacilli and S. mutans in patients, but no statistically significant associations were detected [Table 4] and [Table 5].
|Table 4: Lactobacilli occurrence by age and diagnosis, followed by the Fisher's exact test P value|
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|Table 5: S. Mutans occurrence by age and diagnosis, followed by the Fisher's exact test P value|
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| Discussion|| |
Although this is not a population-based epidemiological survey, the group of analyzed patients reflected the diagnosis estimated by the Brazilian National Cancer Institute pointing to ALL as the most common cancer that affects children up to 15 years old. In this research, 63% of participating children had ALL, agreeing with other studies. , With regard to age and sex of patients, there were no particularities since the sample was intentionally selected.
About 70% of cancer patients in treatment will be submitted to chemotherapy. About 40% of these will develop oral complications as the chemotherapeutic agents act in the proliferating cells irrespective of malignant cells or normal cells of the oral mucosa. The deficiency of oral hygiene or preexistence of infectious foci increases the risk of infection during chemotherapy.  Moreover, oral care starts to not be prioritized by parents or guardians facing the diagnosis of cancer in children, and dental care is often sought only after episodes of pain. This neglect of oral hygiene associated with increased supply of cariogenic food on the basis of oral alterations occurred during treatment (decreased salivary flow sensitivity of the mucous membranes, swallowing difficulty among others already mentioned) potentiates the risk of developing caries in this period. It is, therefore, important to emphasize the importance of the commitment of parents with oral healthcare of their children during the anticancer treatment phase. 
Therefore, the integration between the dentist and the oncologist to keep the patient instructed and accompanied in their oral hygiene is necessary, minimizing the risk of systemic and local complications. ,,,,
Given the importance of saliva in relation to the prevention of dental caries, it has been suggested that salivary testing should be included in routine examinations to assess patients for the risk of developing the disease.  In addition to buffering and salivary flow capacity,  salivary tests can also identify the presence and give an estimative of the number of microorganisms related to tooth decay  as done in this study. These tests offer advantages over conventional methods of culture, biochemical, and immunological methods for such techniques are more time consuming and are not suitable for situations which rapid diagnostic decisions are necessary. 
With the evaluation of the saliva samples collected from the patients, it was found that the risk of developing caries (terminology used by the manufacturer) is low for most groups as 55% of children had lactobacilli lower than 10 4 CFU/ml of saliva. Similar results were obtained when the cariogenic potential (terminology used by the manufacturer) from the CFU of S. mutans was evaluated in which 59% had potential Grade 0. The result differs from that found by Rojas Morales et al. (2006)  that observed a significant increase in the number of CFU of S. mutans in children submitted to anticancer therapies, especially during the period of acute toxicity caused by the administration of the drug (Methotrexate). In relation to the lactobacilli CFU and saliva buffer capacity, there was no significant difference showing the increase these variables before and after administration of chemotherapy.  It is noteworthy that in this study the collections were made only during the administration of chemotherapy.
In a study that compared the prevalence of caries in children under 5 years with cancer with a control group of healthy children of the same age, it was concluded that the prevalence of caries in children with cancer did not differ from children in the control group.  Although this study did not rely on a control group for comparison, there was no difference in the prevalence of dental caries among patients with different types of cancer. Neither relationship was found between the prevalence of dental caries and the occurrence of lactobacilli and S. mutans although these bacteria are related to caries' multifactorial etiology.  However, there was a statistical relationship between the presence of decay teeth and the increasing age of the children. This relationship was expected since the prevalence of caries is directly related to age. 
A statistically significant association between the amount of lactobacilli and DMFT/dmft score was detected in this study. This association had been identified in previous studies involving healthy children  and children with asthma.  However, in these studies, the decay rate was also related to the amount of S. mutans, which did not occur in this study. This may be due to the proportion of children with index 0 of S. mutans in this population. No relationship was found between the occurrence of S. mutans and Lactobacillus and age and diagnosis of patients.
In this study, 61% of children had a current or past history of tooth decay. Dental caries in this particular group of patients corresponds to an increased risk of complications, due to the changes in the organism caused by cancer and by chemotherapy.  However, the occurrence of cariogenic microorganisms found was relatively low, particularly S. mutans. Thus, it is suggested that further studies be conducted with children with cancer using other analysis methodologies of the oral microbiota.
| Conclusion|| |
Despite the high prevalence of dental caries found in this study population, low rates of S. mutans and lactobacilli were found in the saliva of the children. However, the lactobacilli rate was significantly associated with caries index scores, and the prevalence of caries was directly associated with the age group of the children.
Financial support and sponsorship
This study was supported by the State of Mato Grosso Foundation for Research Support - FAPEMAT (Process # 0696).
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]