INTRODUCTION

Diagnosis is an outcome of identifying the signs and symptoms of a disease process, based on scientific knowledge of the disease process and its clinical application.¹ The diagnosis is a result of detection and exclusion of diseases, followed by a prognosis and treatment decision.²

Dental caries is a dynamic disease process that results from metabolic activity in dental biofilm³ that demineralizes enamel and dentin over time.⁴ It is a preventable disease, but with a skewed distribution in the population and a substantial economic and quality-of-life onus.⁵

Correct caries diagnosis is one of the cornerstones in designing an appropriate treatment decision with no over-/undertreatment. Identifying the methods dentists use during daily clinical practice for caries diagnosis and the factors associated with their use is, therefore, a relevant issue.⁶ Studies with dentist members of a dental practice-based research network (PBRN) from the United States, Denmark, Norway, and Sweden have shown that dental explorers and radiographs are still the most commonly used diagnostic methods.⁶ In Brazil, little is known about dental practice patterns of Brazilian dentists regarding caries diagnosis, and this is the first paper showing results that used the same questionnaire (after translation and cultural adaptation) used in the countries described above to assess dental practices.

Therefore, the aim of this paper was to assess the practices related to diagnosis of dental caries among dentists from Araraquara, São Paulo State, Brazil.

METHODS AND MATERIALS

Measures

Results on dentists' demographic and clinical training and practices are presented in Table 1. Table 2 shows the series of questions about caries diagnostic methods, such as use of radiographs; dental explorer for the detection of primary occlusal caries and secondary/recurrent caries at the margins of existing restorations; air drying (AD) for primary caries; laser fluorescence (LF) for primary caries on occlusal surfaces; and fiber optic transillumination for proximal lesions in anterior teeth. The response choices were 0%, 1%-24%, 25%-49%, 50%-74%, 75%-99%, and 100%. The percentages for each caries diagnostic method were coded to the categories' median to maintain the interval nature of the data so that parametric statistics could be used: 0% = 0%, 1%-24% = 12.5%, 25%-49% = 37%, 50%-74% = 62%, 75%-99% = 87%, 100% = 100%.⁶

Table 1 Participant Characteristics by Sex and for the Total Sample

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Table 2 Questions to Assess Methods Used to Diagnose Dental Caries

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RESULTS

Table 3 summarizes the frequency of use of caries diagnostic methods. Air drying was the method used in almost all patients (92%), on average, to diagnose caries. The use of an explorer in occlusal surfaces and in the margin of existing restorations is also common for most patients. The diagnosis of proximal caries using radiographs is performed on average in 59% of the patients. On the other hand, magnification (25%), fiber optic transillumination (FOTI; 14%), and LF (3%) were used in the minority of patients.

Table 3 Frequency of Use of Caries Diagnostic Method

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Table 4 shows results of linear regressions of the frequency of use of each diagnostic method, using practitioner and practice characteristics as covariates. Significant associations at p<0.05 are described below.

Table 4 Linear Regressions of Use of Each Diagnostic Method, With Practitioner and Practice Characteristics as Covariates

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As shown in Table 4, dentists who use radiographs to diagnose caries on posterior teeth on a greater percentage of their patients are more likely to have an advanced degree (p=0.002 for occlusal lesions and p<0.001 for proximal lesions) and provide a higher percentage of patients with individualized caries prevention (p<0.001 for proximal surfaces). On the other hand, those with a greater number of years since dental school graduation use radiographs on proximal (p=0.010) and occlusal (p=0.007) surfaces on a smaller percentage of their patients.

Dentists who use explorers on occlusal surfaces and on the margin of an existing restoration on a greater percentage of their patients have a greater number of years since dental school graduation (p=0.041 for occlusal lesions; p=0.038 for margin of a restoration). However, those who have received specialty training (p=0.039) and those with an advanced degree (p=0.004) use explorers on occlusal surfaces on a smaller percentage of their patients.

Dentists who use LF on occlusal surfaces on a greater percentage of their patients are more likely to work in an exclusively private practice model (p=0.003).

Dentists who use fiber optic transillumination for proximal caries on a greater percentage of their patients are more likely to have received an advanced degree (p=0.022) and provide a higher percentage of patients with individualized caries prevention (p=0.020). Female dentists (p=0.046) and those having a primarily pediatric dentistry practice (p=0.027) use FOTI on a smaller percentage of their patients.

Dentists who use magnification on a greater percentage of their patients have a greater number of years since dental school graduation (p=0.002) and provide a higher percentage of patients with individualized caries prevention (p=0.013).

DISCUSSION

In this paper, we identified the methods that Brazilian dentists use to diagnose dental caries and which variables are significantly associated with them, because little is known about dental practice patterns regarding caries management in Brazil.

Diagnostic methods used by dentists in most patients were AD (92%), dental explorer (Ex) for occlusal caries (64%) and for the margin of existing restorations (79%), and radiographs (Rx) (59%) for proximal caries. FOTI (14%) and LF (3%) were used in the minority of patients by the participants. Gordan and others⁶ found similar results among PBRN dentists for using dental explorers and radiographs in proximal caries. For FOTI and LF, a systematic review has shown insufficient scientific evidence for diagnostic accuracy of such methods.¹²

The finding that visual-tactile examination was used by dentists in most patients is in accordance with other studies. Most general dental practitioners' from New Zealand preferred conventional visual-tactile (87%) and digital radiography (78%) among several methods for caries detection.¹³ For private dental practitioners from Ankara, Turkey, sharp explorers were one of the most commonly used instruments to detect carious lesions.¹⁴

In fact, Nyvad and others¹⁵ demonstrated that an attentive professional using AD can diagnose most initial carious lesions by visual-tactile inspection. It is a quick and easy method, and when associated with assessment of lesion activity, is the best choice for the diagnosis of caries.¹⁶ However, the use of sharp explorers may cause some damage to the dental surface.¹⁷ In an in vitro study comparing ultrastructural defects caused in primary teeth by ball-ended probes and sharp explorers, the findings showed that less damage was caused using ball-ended probes when probing primary dental surfaces.¹⁸ Moreover, professionals tend to over-diagnose the disease when they use a sharp explorer because a “sticking” probe may be entirely due to pit and fissure anatomy.⁶

According to Fontana and others,¹⁹ an explorer should be used very gently to remove debris and plaque, to confirm cavitation when in doubt, to help the assessment of lesion activity and of dental material's integrity and retention. Systematic reviews have showed that visual methods had good accuracy for detecting carious lesions,²⁰ and they should remain the standard for clinical assessment in dental practice.²¹

Dentists in the current study use proximal radiographs for the diagnosis of proximal caries in almost 60% of their patients (Table 3). These findings, although lower than those reported in other practice-based studies, still show that the majority of dentists use radiographs in their patients for assessment of proximal surfaces as shown by 96% of dentists in the United States⁶ and by dentists in Ankara (Turkey) who used radiographs in almost all their patients.¹⁴ One possible explanation for this finding is that 46% of the dentists participating in the current study work in public health settings. A radiographic imaging unit may not be available in some public health settings. In a Brazilian study that investigated dental radiology services in the public health setting, investigators found that 46% of municipalities from the Midwest region of Minas Gerais State did not have a radiographic imaging unit.²² Another Brazilian study that assessed the weaknesses in public dental service of a city from the South Region, the interviewed dentists reported the lack of X-ray equipment as one of the main criticisms to the public service.²³

Radiographic examination seems especially suitable for detecting cavitated proximal lesions in dentin. However, for enamel or incipient proximal caries lesions, the method presents low sensitivity and high specificity.²⁴ According to Pretty and Ekstrand,²⁵ the reproducibility from bitewing radiographs varies widely and they suggest that radiographs can aid the assessment of dentin proximal lesions, but are not as good as visual inspection for occlusal lesions. Therefore, they argue that radiographic examination is indicated when additional information is needed to aid dentists in the decision-making process. Additionally, it can be used to monitor early proximal lesions.

Another interesting finding is that regression analyses showed an inverse relationship for the use of radiographic imaging and years since graduation from dental school. There are very few studies on radiographic imaging use by Brazilian dentists. Castro and others²⁶ assessed availability of radiographic imaging to dentists in the city of Belo Horizonte and observed that recent graduates, up to 30 years of age, had more X-ray machines in their offices (72%) than those aged more than 30 years. The authors also found that dentists up to 20 years since graduation showed greater knowledge about radiographic techniques and radioprotection compared with dentists with 21+ years since graduation.

The results of the regression analysis showed that some dentists' characteristics were significantly associated with the use of certain caries diagnostic methods: dentists with an advanced dental degree were more likely to use radiographic imaging and FOTI. Dentists who practiced individualized caries prevention in their patients were more likely to use radiographic imaging, FOTI, and magnification. Dentists with greater number of years since dental school graduation were more likely to use an explorer and magnification. Dentists who work exclusively in private practice are more likely to use LF (Table 4).

One of the most relevant findings of this study is the frequency of the use of a dental explorer on occlusal lesions and on margins of existing restorations in most patients, as previously mentioned. Regression analyses showed a direct relationship for the use of a dental explorer in occlusal caries lesions and years of graduation from dental school and an inverse relationship between dentists who have postgraduation courses and use of the dental explorer for caries diagnosis. Dentists who have a postgraduation course are most likely to practice dentistry based on current evidence, whereas dentists with more years of graduation from dental school may be more accustomed to traditional methods of caries diagnosis, such as the use of a sharp dental explorer. Indeed, Fontana and others²⁷ reported that teaching the use of a dental explorer to diagnose occlusal caries was the gold standard for many decades.

Regression analysis also showed a direct relationship between the use of radiographic imaging to diagnose caries on posterior teeth and dentists with an advanced degree, as well as with dentists who provide individualized caries prevention treatment for their patients. These findings were consistent with Gordan and others,⁶ who found that dentists who provide individualized caries prevention treatment are more likely to use radiographs to assess proximal caries.

Although other methods such as LF, FOTI, and magnification were not used by most dentists, the regression analyses showed that dentists who use LF on occlusal surfaces on a greater percentage of their patients are more likely to work in an exclusively private practice model. It does make sense because most public services in Brazil do not have these adjunct technologies. In a recent systematic review about the accuracy of LF in in vitro caries diagnoses, the results showed that the method was accurate (sensitivity, 0.71; specificity, 0.81) in predicting caries or healthy surfaces; however, the authors believe that in clinical practice, LF alone is not enough for an accurate caries diagnosis.²⁸

Dentists who use magnification on a greater percentage of their patients have a greater number of years since dental school graduation. It seems that older dentists use magnification more frequently than younger dentists and this could be explained because presbyopia is a common deficiency affecting visual acuity that can begin in the 40s and can be compensated with magnification aids.²⁹

The limitations of this study, besides being a cross-sectional design, include that results are from a self-selected group of dentists. Despite the low response rate, the strengths of this study include the similarity for sex and age between study participants and practicing dentists in Araraquara. The study also proved to be feasible as a tool to investigate the current practice of dentistry, and it can be used to compare the results with other dentist populations.

The study findings identified a gap between dentists with more years of clinical experience and the practice of current evidence-based dental care. Future research could assess whether additional training and continuing education courses are indicated to improve the delivery of standard of care in dental offices by dentists who graduated many years ago and who did not complete postgraduate training.

CONCLUSION

In conclusion, most Brazilian dentists from Araraquara reported they most commonly use visual, tactile, and radiographic imaging for the diagnosis of dental caries. Some dentists' characteristics, such as years since dental school graduation and having postgraduation education, were associated with the use of certain diagnostic methods.