Summary of findings 1. Summary of findings table.
| Question | What is the diagnostic accuracy of transillumination‐based index tests for the detection and diagnosis of early dental caries? | |||
| Population | Children or adults who are presenting asymptomatically or are suspected of having enamel caries (clinical studies); extracted teeth of children or adults (in vitro studies). Studies which intentionally included dentine and frank cavitations were excluded | |||
| Index test | Transillumination‐based devices ‐ including near‐infrared (NIR), optical coherence tomography (OCT), and fibre‐optic transillumination (FOTI)/digital fibre‐optic transillumination (DIFOTI), suitable for use as an adjunct to a conventional clinical oral examination. The index tests produced an enhanced view of the tooth and were interpreted by a trained examiner | |||
| Comparator test | Comparisons were made between transillumination devices. A separate review in this series investigates comparisons between transillumination‐based tests and enhanced visual, radiograph, and fluorescence tests | |||
| Target condition | Dental caries, at the threshold of caries in enamel | |||
| Reference standard | Histology, enhanced visual examination with or without radiographs | |||
| Action | If dental caries can be detected at an early stage then remedial action can be taken to arrest or reverse the decay and potentially prevent restorations | |||
| Diagnostic stage | Aimed at the general dental practitioner assessing regularly attending patients for early stage caries | |||
| Quantity of evidence | 23 studies providing data for meta‐analysis (24 datasets, 16,702 teeth, 2499 tooth surfaces with total caries at enamel threshold or greater (15% prevalence)) | |||
| Findings | All studies (24 datasets) | NIR (6 datasets, 673 tooth surfaces, 56% prevalence) | OCT (10 datasets, 1171 tooth surfaces, 52% prevalence) | FOTI/DIFOTI (8 datasets, 14,858 tooth surfaces, 10% prevalence) |
| Sensitivity (95% CI)a | 0.75 (0.62 to 0.85) | 0.58 (0.46 to 0.68) | 0.94 (0.88 to 0.97) | 0.47 (0.35 to 0.59) |
| Specificity(95% CI)a | 0.87 (0.82 to 0.92) | 0.86 (0.80 to 0.91) | 0.83 (0.68 to 0.91) | 0.92 (0.86 to 0.96) |
| DOR (95% CI) | 21.52 (10.89 to 42.48) | 8.65 (3.92 to 19.06) | 72.07 (23.87 to 217.66) | 10.75 (4.49 to 25.72) |
| Effect per 1000 tooth surfaces assessed | Numbers applied to a hypothetical cohort of 1000 tooth surfaces (95% CI) | Test accuracy Certainty of the evidence | ||
| Outcome | Pre‐test probability 28%b | Pre‐test probability 57%b | ||
| True positives (patients with early enamel caries) | 210 (174 to 238) | 428 (353 to 484) | ⊕⊕⊝⊝ LOW |
|
| False negatives (patients incorrectly classified as not having early enamel caries) | 70 (42 to 106) | 142 (86 to 271) | ||
| True negatives (patients without early enamel caries) | 626 (540 to 662) | 374 (353 to 396) | ||
| False positives (patients incorrectly classified as having early enamel caries) | 94 (58 to 180) | 56 (34 to 77) | ||
| Limitations ‐ factors that may decrease the certainty of the evidence | ||||
| Risk of bias | Of the 23 studies: the participant selection domain had the largest number of studies judged at high risk of bias (16 studies). Conversely, for the index test, reference standard, and flow and timing domains the majority of studies were judged to be at low risk of bias (16, 12, and 16 studies respectively) For the index test domain, 2 studies suggested that the index test may have been influenced by the reference standard, a further 3 lacked independent examiners, and 1 was unclear on whether the threshold was predetermined The reference standard was deemed to have correctly classified the target condition in 12 studies and was interpreted without knowledge of the index test in 12 studies There was no concern regarding the interval between the index test and the reference standards in 21 studies, the same reference standard was used for all tooth surfaces in 23 studies, and all tooth surfaces were reported in the analysis in 12 studies |
|||
| Applicability of evidence to the review question | High concern was observed for patient selection where extracted teeth were used (14 studies), where the index test applied a device that is not currently available to a general dental practitioner (4 studies), and where the reference standard was a radiograph (4 studies) | |||
| Certainty of the evidence | We rated the certainty of the evidence as low and downgraded 2 levels in total due to avoidable and unavoidable study limitations in the design and conduct of studies, indirectness arising from the in vitro studies, and imprecision of the estimates | |||
aSummary estimates of sensitivity and specificity were reported for all included studies but the 3 groups of devices vary in their design and use so it was necessary to present the results of the subgroups within the 'Summary of findings' table. bPrevalence values of 28% and 57% were used to calculate the natural frequencies based on the summary estimates. The prevalence of all assessed surfaces included in this review was 15%, however the overall prevalence was skewed downwards by 3 large studies in the FOTI/DIFOTI group where the prevalence was comparatively low at 3%, 16%, and 19%. The pre‐test probabilities of 28% and 57% were used to facilitate comparisons of results with other reviews in this series, and also serve as a more representative prevalence for the 18 NIR and OCT studies included in this review. Based on consultation with clinical colleagues, the lower prevalence value of 28% addresses concerns regarding the representativeness of the overall prevalence value in this review. The 28% value is taken from the level of cavitated teeth reported in the UK Adult Dental Health Survey (Steele 2011). The higher prevalence value is taken from the prevalence of enamel caries in the fluorescence review in this series (Macey 2020).
CI: confidence interval; DOR: diagnostic odds ratio.