Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial

ABSTRACT Objective: This study evaluated the effectiveness of preventive strategies on caries risk reduction in patients undergoing orthodontic treatment, using the Cariogram program. Methods: In this quasi-experimental study, samples were selected using a convenience quota sampling technique, in a public dental school. At first, caries risk profile was determined for each subject using the Cariogram before brackets bonding. The sample size consisted of 36 patients. The intervention group (n = 18) received preventive programs, and the control group (n = 18) was trained based on the routine oral health education by means of pamphlets. Then, Cariogram parameters were calculated for patients in both groups after six months. Results: The age range of participants was from 12 to 29 years. The mean percentage of the “Actual chance of avoiding new cavities” section in the intervention group increased from 45.72 ± 21.64 to 62.50 ± 17.64. However, the mean percentage of other parameters - such as “Diet”, “Bacteria” and “Susceptibility” - decreased after six months (p< 0.001). Besides, the differences in the mean percentage between intervention and control group at the end of the study period (T1) related to the Cariogram parameters were statistically significant (p< 0.001). Accordingly, the mean percentage of ‘Actual chance of avoiding new cavities’’ parameter in the intervention group (62.50) was statistically higher than in the control group (42.44) (p< 0.001). Conclusion: Implementing different preventive approaches is able to reduce the caries risk in patients undergoing fixed orthodontic treatment, which can be clearly demonstrated using Cariogram program.


INTRODUCTION
Oral cavity is the habitat of various bacterial species, mycoplasma, protozoa, and yeasts, and any external interference can disturb the balance of microbiota in this environment. 1 The traditional concept of caries as a multifactorial transmittable and infectious disease has been questioned. The current etiological concept of dental caries has emphasized the important role of sugars in caries. The current definition points toward an ecological disease caused by the commensal microbiota that, under ecological imbalances, mainly due to high and or frequent sugars consumption, creates a state of dysbiosis in the dental biofilm. It is currently accepted that caries is a sugars and biofilm-dependent disease. Acid-producing bacteria and other factors facilitate the development of dental caries.
Also, salivary flow, fluoride exposure, plaque accumulation, tooth morphology and structure would create more favorable or adverse conditions for the causal relation between sugars and the dental biofilm to induce carious lesions. 2 The development of dental caries is determined by the balance of protective and risk factors. If the dentist can recognize the relationship between these factors and the development of the disease or its relapse, the risk of caries will be reduced. 3,4 Environmental, behavioral, and biological factors can be identified as risk factors associated with the incidence of the disease. 5 Fixed orthodontic appliances such as brackets are Doost-Hoseini M, Seifi M, Pakkhesal M, Saboury A, Amdjadi P, Naghavialhosseini A Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial 5 examples of environmental factors. They are associated with increased plaque accumulation around the brackets and thus increase the burden of Streptococcus mutans and lactobacillus contamination in saliva and biofilm. 6 The introduction of fixed appliances into the oral cavity not only intensify the amount of biofilm formation, but also increases the level of acidogenic bacteria inside the biofilm, resulting in a higher cariogenic challenge around orthodontic brackets and bands. If patients cannot maintain good oral hygiene during orthodontic treatment, the acid produced by dental biofilms will eventually lead to enamel demineralization and white spot lesions. 7,8 Caries Risk Assessment (CRA) is an important phase in dental treatment based on the strategy of minimally invasive therapy, in which therapeutic and prophylactic measures are planned, based on the results of CRA. 9 There is a number of available questionnaires and tests that first identify the level of risk exclusively for each patient, and allocate that individual into one of these three categories: low risk, moderate risk, or high risk. Cariogram model evaluates the data based on its algorithm and presents the results as a circular color chart representing five different groups of indicators, including: "Actual chance to avoid new cavities", Diet, Bacteria, Susceptibility, and Circumstances. 10,11 Doost-Hoseini M, Seifi M, Pakkhesal M, Saboury A, Amdjadi P, Naghavialhosseini A Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial 6 Next, appropriate preventive interventions may be done for each orthodontic patient. They can be motivated through regular stimulations that can encourage healthy behaviors in them.
Reinforcement is one of the most important bases of health education, which helps patients to adopt healthy behavior and lifestyles. Text message reminder is able to improve the oral hygiene of patients undergoing orthodontic treatment. 12 Therefore, we attempted to assess the effect of preventive strategies on reduction of caries risk in the intervention group.
The present study was an experimental clinical research that analyzed all parameters of the Cariogram program, to evaluate the risk of caries in orthodontic patients treated with fixed appliances.

MATERIAL AND METHODS
The present study was approved by the regional Research Ethics Committee (IR.SBMU.RIDS.REC.1395.250) and performed in complete accordance with the Declaration of Helsinki. Written informed consent was taken from the patients before the start of the research. Moreover, the data was handled anonymously and with confidentiality in all stages of the study. The researcher handled the data pseudonymized in the present study to protect the privacy of study participants while collecting, analyzing, Doost-Hoseini M, Seifi M, Pakkhesal M, Saboury A, Amdjadi P, Naghavialhosseini A Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial 7 and reporting data. The method of pseudonymization comprised separating identifying personal data from the questionnaire and preserving it with participants' dental charts. In other words, two-time points Cariogram questionnaires were linked using a unique identification code allocated to each participant.
The sample size was calculated based on the data obtained from a previous study 13 , keeping a significance level of 0.05, standard deviations within groups of 30 units, a least detectable difference of 20 units between groups on the Cariogram, and power for that detection of 80%. Therefore, the sample size for each group was determined to be 18. Since there were two groups (intervention and control), the final sample size was determined to be 36.
Sampling was done using a quota sampling technique, in which samples were assigned from each caries risk profile (low, moderate, and high) until the sample met the minimum requirement in each study group.
Inclusion criteria comprised orthodontic patients over 12 years old, with the ability to speak and understand the native language, and who needed fixed orthodontic treatment in both arches for at least six months. Exclusion criteria were: moderate The standard Cariogram questionnaire was completed for all participants. Each of the nine caries-related factors was ranked from 0 to 2 or 0 to 3, based on the manual (Table 1). Then all data were entered into Cariogram program, in order to provide a graphic image to show the true chance of avoiding new caries cavities as percentages. The tenth factor (''clinical judgment") was given a score of 1 in all patients, which means that the caries risk was evaluated according to the other scores in the Cariogram.
On the other hand, it shows the researcher's agreement with the Cariogram program to evaluate caries' risk in a normal condition.

Caries experience
The clinical examination was conducted in the orthodontic department of Shahid Beheshti dental school (Tehran/Iran), on a dental chair using mouth mirror, a standard light, and a dental probe. Caries was scored according to the World Health Organization (WHO) criteria, using DMFT index (number of decayed, missing, and filled teeth).
Moreover, all oral examinations were performed by a single trained and calibrated researcher. Hence, only intraexaminer reliability was determined. Thus, the oral examination of 10 randomly selected subjects was repeated on different dates, to determine intraexaminer reliability. The Kappa coefficient value for intraexaminer reliability was 0.87, which is interpreted as very good.
Doost-Hoseini M, Seifi M, Pakkhesal M, Saboury A, Amdjadi P, Naghavialhosseini A Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial

Factors
Information and data collected Cariogram scores

-Caries experience
Previous caries experience at baseline, including cavities, filling and missing teeth due to caries 0: Caries-free and no filling 1: Lower than the age group range 2: Within the age group range 3: Higher than the age group range

-Related diseases
General disease or conditions associated with dental caries, data from interviews and questionnaire   In collaboration with the oral health authorities, the previous history of caries was appointed, based on findings of a national oral health survey conducted in Iran in 2011 14 (Fig 1). Thus, the condition of previous caries was rated from 0 to 3:  Saliva was collected between 9:00 a.m. and noon, to minimize circadian rhythm effects, and at least an hour after drinking or eating food.
The steps to evaluate the amount of saliva flow were as follows: » The patient should be seated in an upright and comfortable position.
» The patient should chew a paraffin pill for 30 seconds and then remove the stored saliva or swallow it.
» The patient should continue to chew for 5 minutes and accumulate saliva continuously in a sterile flask tube.
» After 5 minutes, the amount of saliva is measured, and the amount of stimulated saliva revealed (milliliter per minute) is given 0 to 3 points (according to row 8 in Table1).

Buffering capacity
A 5 or 6-cm piece of litmus paper was placed in the test tube for 2 seconds. Once the color of the paper changed, the pH of the solution was deduced, by comparing the color of the paper with the color of the guide and, according to acid-base level, buffer capacity was determined as 0 to 2 points (according to row 9 in Table 1). which evaluates the given data based on its algorithms, and presents the results as a pie chart, indicating five different groups of factors related to dental caries, as follows:

1) Actual chance of avoiding new cavities:
The green section shows an estimation of the "actual chance to avoid new cavities". Patients are divided into three groups: high risk group (0-40%), moderate risk (40-60%) and low risk (60-100%) based on the percentage obtained from this section.

2) Diet:
A dark blue section that shows the combined dietary content and its frequency.

3) Bacteria:
The red part shows a combination of the amount of Streptococcus mutans and plaque.

4) Susceptibility:
The light blue section shows a combination of three factors: the amount of fluoride intake; the amount of saliva secretion; and the saliva buffering capacity.

5) Circumstances:
The yellow section is based on a combination of medical and dental history.
During the six-month study period, the researchers examined the patients who were in the intervention group, and asked them to demonstrate the correct use of toothbrushes and den-

RESULTS
The intervention group included 7 males and 11 females, and the control group consisted of 8 males and 10 females. The age range of participants was between 12 and 29 years, with the mean age of 19.6 ± 4.66 years and 19.28 ± 3.30 years in the intervention and control groups, respectively.
The various caries-related factors of Cariogram that were compared between the two groups at the beginning of treatment and after six months are shown in Table 2 18 Independent sample t-test and covariance statistical method (ANCOVA) were used for analysis of the differences between baseline and after six months follow-up of both groups in the scores of the Cariogram parameters, and p-value < 0.05 was considered as significant. Also, there was significant difference between both study groups (p < 0.001), as illustrated in Table 3.

DISCUSSION
The present study focuses on the caries risk assessment in There have been many studies about increased caries risk in fixed appliances therapy, which has multiple factors in relation to orthodontic treatment, caries development, plaque accumulation, and effect of fluoride. 18,19 In the present study, caries risk assessment using Cariogram indicated no single factor explaining the changes observed. Almosa et al. 13 used Cariogram to evaluate the factors related to caries between orthodontic patients treated in governmental and private centers immediately after orthodontic treatment.
The results indicated that the percentage of an actual chance Doost-Hoseini M, Seifi M, Pakkhesal M, Saboury A, Amdjadi P, Naghavialhosseini A Evaluation of caries risk reduction following preventive programs in orthodontic patients, using Cariogram computer model: A quasi-experimental trial 24 of avoiding new cavities in patients in public centers was lower than in private centers (28% and 61%, respectively). Also, DMFS, plaque index, number of Streptococcus mutans and lactobacillus, and salivary buffer capacity were significantly higher in the public group, compared with the private centers. The total number of caries lesions at debonding in the public group was more than two times higher than that in the private group. 13 The current study was conducted only in a governmental, educational dental school, and supported the evidence related to caries risk assessment and individualized caries prevention strategies as an effective method of caries management.
Further studies must compare large samples from different health centers (public and private clinics), with subjects in various situations (socio-economic status), to confirm the efficiency of preventive approaches for patients undergoing fixed orthodontic treatment. Besides, the present study had another limitation related to study design, that is, quasi-experimental design, which lacks true randomization. Overall responsibility:

MP.
The authors report no commercial, proprietary or financial interest in the products or companies described in this article.