Astvaldsdottir 2012.

Study characteristics
Patient Sampling	Method of sampling: selected Included conditions: no cavitation and early lesions; "The approximal surfaces of the selected teeth presented a range of conditions, from sound to non‐cavitated and cavitated caries lesions" Teeth: permanent premolars Sealants: not reported Restorations: not reported Surface: approximal
Patient characteristics and setting	Age: not reported Sex: not reported Ethnicity: not reported Country: Sweden Setting: extracted teeth Number of participants/teeth/sites: 56 teeth, 112 sites Prevalence: enamel 0.64, dentine 0.15
Index tests	Category of test: DIFOTI images Sequence of test(s): index tests (radiographs and transillumination) performed prior to reference standard Examiner training and calibration: 8 experienced examiners: "all observers underwent a 15‐minute training session to become familiar with the technique" Threshold applied: sound outer/inner enamel, outer/inner dentine Device specifics: "All DIFOTI images were captured by a trained operator under standardized darkroom conditions. The DIFOTI instrument (Electro‐Optical Sciences Inc, NY) was used as recommended by the manufacturer"
Target condition and reference standard(s)	Category: histology Sequence of index test and reference standard: index test then reference standard Training of examiner: not reported Blinding to index test: unclear Multiple tests: no Site selection: sectioned teeth Target condition: sound, enamel, dentine
Flow and timing	Participants with index test but no reference standard: 15 surfaces out of 112 damaged during preparation of reference standard Participants with reference standard but no index test: 0 Time interval between tests: minimal Participants receiving both tests but excluded from results: 0
Comparative
Notes	Results taken for examiner 1
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
Could the selection of patients have introduced bias?		High risk
Are there concerns that the included patients and setting do not match the review question?			High
DOMAIN 2: Index Test (All tests)
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
If a threshold was used, was it pre‐specified?	Yes
If multiple tests were applied were different examiners used for each (in vivo)?	Unclear
Could the conduct or interpretation of the index test have introduced bias?		Unclear risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
Could the reference standard, its conduct, or its interpretation have introduced bias?		Low risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	No
Could the patient flow have introduced bias?		Low risk