Review Article

Artificial Intelligence Techniques: Analysis, Application, and Outcome in Dentistry—A Systematic Review

Table 2

Characteristics of selected studies ().

Author and yearStudy designGroupsApplicationAssessment methodFollow-up periodOutcome
StudyControl

Abdalla-Aslan et al. [5] 2020Cohort studyMachine learning computer vision algorithmsNAODAutomatic algorithm was used to detection and classification restoration while vector machine algorithm with error-correcting output codes was applied for cross-validationNAMachine learning demonstrated excellent performance in detecting and classifying dental restorations on panoramic images
Bouchahma et al. [6] 2019Clinical trialCNNNMOD and endodonticsPrediction of three types of treatments; fluoride, filling, and root canal treatments. The model was trained to learn on dataset of 200 X-ray images of patients’ teeth collectedNMDL overall accuracy was 87%. The best prediction was the fluoride treatment with 98%, followed by RCT detection 88% and filling 77%
Kuwada et al. [7] 2020Clinical trialDetectNet, AlexNet, and VGG-16NMOD400 images were randomly selected as training data, and 100 as validating and testing data. The remaining 50 images were used as new testing data. Recall, precision, and F-measure were used for detection of impacted teethNMDetectNet and AlexNet appear to have potential use in classifying the presence of impacted supernumerary teeth in the maxillary incisor region on PR, while VGG-16 showed lower values
Lee et al. [8] 2020Clinical trialCNN on 20 automated 20 tooth segmentsOral radiologist manually performed individual tooth annotation on the PAOD and forensic dentistry846 images with tooth annotations from 30 PA were used for training, and 20 as the validation and test sets. A fully deep learning method using the mask R-CNN model was implemented through a fine-tuning process to detect and localize the tooth structuresNMIt achieved high performance for automation of tooth segmentation on dental panoramic images. The proposed method might be applied in the first step of diagnosis automation and in forensic identification
Ekert et al. [9] 2019Clinical trialCNN to detect ALSix independent examiners detect ALEndodontics and ODNN was trained and validated via 10 times repeated group shuffling. Results were compared with the majority vote of 6 examiners who detected ALs on an ordinal scaleNMA moderately deep CNN showed satisfying discriminatory ability to detect ALs on panoramic radiographs
Saghiri et al. [10] 2012Clinical trialANNEndodontist’s opinionEndodonticsWorking length was determined and confirmed radiographically by endodontists and compared with ANN, and stereomicroscope as a gold standard after tooth extraction in cadaverNMANN was more accurate than endodontists’ determinations when compared with measurements by using the stereomicroscope
Arisu et al. [11] 2018Clinical trialANNNMRestorative dentistryObtained measurements and data were fed to an ANN to establish the correlation between the inputs; composite shade curing units and outputs; tooth numberNMANN showed that the light-curing units and composite parameter had the most significant effect on the bottom to top Vickers hardness ratio of the composites
Yamaguchi et al. [12] 2019Clinical trial12 dislodge CAD/CAM composite resin crowns with DL12 trouble-free CAD/CAM composite resin crownsRestorative dentistryConvolution neural network (CNN) technique was used to predict debonding of composite crowns using 2D images captured from 3D stereolithography modelsNMDeep learning with CNN model showed good performance in terms of dislodgement predictability of composite crowns through 3D stereolithography models
Otani et al. [13] 2015Experimental studyTen veneer preparation with a robotic armTen conventional veneers prepared by a clinicianRestorative dentistryAccuracy and precision of veneer preparation were compared for all sites and separately for each tooth surface (facial, finish line, incisal) through 3D images and computationNMThe robotic arm was able to prepare the tooth model as accurately as the control. However, a better finish line accuracy and precision was showed by the robotic arm
Wang et al. [14] 2014Experimental studyAutomatic laser ablation system for tooth crown preparationNMProsthodonticsA layer-by-layer ablation method is developed to control the laser focus during the crown preparationNMThe movement range and the resolution of the robotic system meet the satisfying requirements of typical dental operations for clinical crown preparation
Takahashi et al. [15] 2020Experimental studyCNNNMProsthodontics and OD1184 images of dental arches were classified into four arch types. A CNN method to classify images was developed using tensor flow and Kera’s deep learning librariesNMThe results of this study suggest that dental arches can be classified and predicted using a CNN
Patcas et al. [16] 2019Cohort studyCNN was applied in posttreatment photographs of 146 orthognathic patientsPretreatment photographs of 146 patientsOrthodonticsCNN-based technique was used to compare facial attractiveness and apparent age of patients through pre- and posttreatment photographsNAArtificial intelligence can be used to detect facial attractiveness scores and apparent age in orthognathic surgery patients
Li et al. [17] 2020Clinical trial50 oral images and 274 anterior through automated photo integrating systemManual segmentation systemEsthetic dentistryThe facial and intraoral key points were detected by an automatic algorithm and compared with manual segmentation on standard photographsNMThe proposed automated system can eliminate the need for dentists to employ a laborious image integration process and has potential for broad applicability in the field of esthetic dentistry
Li et al. [44] 2015Experimental studyBPNN and GA neural networkTraditional neural networkEsthetic dentistryThe weighs and threshold values of GA and BPNN were compared for assistance in tooth color matching in dentistryNMGA and BP have practical application and can make teeth color matching objective and accurate
Edinger [30] 2004Clinical trialROSY, a robot-like electronic simulatorNMProsthodonticsAccuracy of the simulator was measured for all directions in space by registering eccentric jaw positions on both sides of 10 subjectsNMIts accuracy may render it suitable for clinical applications
Meissner et al. [31] 2006Clinical trialAutomated smart ultrasonic calculus detection systemNMPeriodonticsThe detection device is based on a conventional dental piezoelectric ultrasonic hand piece with a conventional scaler insertNMIt was able to distinguish between different tooth surfaces in vitro independently from tip movements
Meissner et al. [32] 2005Clinical trialA novel calculus recognition device applied on 70 extracted teethNMPeriodonticsImpulse generator, coupled to a conventional piezo-driven ultrasonic scaler, sends signals to the cementum via the tip of an ultrasound deviceNMThis system is able to function correctly, independent of the lateral forces and the tip angle of the instrument
Devito et al. [33] 2008Clinical trialMultilayer perceptron neural networkTwenty-five dental specialists with 20 years’ experienceODEvaluation of proximal caries on radiographic through ANNNMAI improves the radiographic diagnosis of proximal caries by 39.4%
Kositbowornchai et al. [34] 2006Clinical trialLearning vector quantization (LQV, NN)NMRestorative dentistry and ODTooth sections and microscopic examinations were used to confirm the actual dental caries statusNMAI plays a useful and supporting in making dental caries diagnosis
Patcas et al. [35] 2019Clinical trialTen images evaluated by CNN modelTen images were analyzed by laypeople, orthodontists, and oral surgeon on a visual analogue scaleOrthodonticsDecision on profile and frontal images of cleft patients were compared between CNN technique and conventional rater group to evaluate facial attractivenessNMAI can be a helpful tool to describe facial attractiveness and overall analysis were comparable with the rater groups
Lee et al. [36] 2018Clinical trialCNNFour calibrated board-certified dentistsOD and restorative dentistryA pretrained GoogleNet Inception v3 CNN network was used for preprocessing and transfer learningNMCNN provides considerably good performance in detecting dental caries in PR
Vranckx et al. [37] 2020Clinical trialCNN and ResNet-101Manual measurements by 2 observersODCNN and ResNet-101 jointly predicted the molar segmentation maps and an estimate of the orientation linesNMFast, accurate, and consistent automated measurement of molar angulations on dental PR
Lee et al. [38] 2020Clinical trialFifty cases of class2 TMJOAFifty cases of normal TMJOMFSThe condylar head was classified into 2 categories and tested by making 300 imagesNMAI can be used to support clinicians with diagnosis and decision making for treatments of TMJOA
Hung et al. [39] 2019Clinical studyMachine learning method ANN was used on bitewing radiographTraining group consisting of conventional radiograph analysisGerontologySupport vector machine (ANN) was used to detect root caries on radiograph by determining AUCNMSupport vector machine showed 97.1% accuracy, 95.1% precision, 99.6% sensitivity, and 94.3% specificity for root caries detection
Cui et al. [27] 2020Cohort studyCDS model applied to 3559 patient recordsTwo prosthodontists’ opinionOMFSCDS model was used to predict the outcome of teeth extraction through electronic dental recordsNAThe machine learning CDS was an efficient tool to predict teeth extraction outcome
Sornam and Prabhakaran [40] 2019Clinical studyLB-ABC with BPNNBPNN classifierRestorative dentistryThe BPNN classifier is compared with the LB-ABC-based BPNN classifier for dental caries classificationNMThe learning rate generated by the LB-ABC for the BPNN classifier achieved the best training and testing accuracy of 99.16%
Setzer et al. [41] 2020Clinical studyEvaluation of periapical lesion by DL methodRating by OMF radiologist, an endodontist, and a senior graduate studentEndodonticsThe CBCT segmentation was assessed by DL, CNN detectionNMDL algorithm trained in a limited CBCT environment showed excellent results in lesion detection accuracy
Cantu et al. [42] 2020Clinical studyCaries detection on bitewing radiograph with DLOpinion of four experienced dentistsOD, ORCNN (U-Net) and Intersection-over-Union were used to detect caries on radiographsNMThe deep neural network was accurate than dentists
Aliaga et al. [45] 2020Experimental studyAutomatic computation and intelligent image segmentation of 370 radiographsExpert dentist opinionOD, OMFSAutomatic computation for analysis of mandibular indices and osteoporosis detectionNMAutomatic computation of mandibular indices and intelligent image segmentation was an efficient and reliable approach for early osteoporosis detection
Kim et al. [28] 2018Case-control studyMachine learning prediction models for BRONJ after extraction in 125 patients with drug useConventional methods, serum CTX levelOMFS/OMFive machine learning methods such as logistic regression model, decision tree, support vector machine, ANN, and random forest were applied to predict BRONJ at extraction sitesNAMachine learning showed superior performance in predicting BRONJ compared with serum CTX level and drug holiday period
Dumast et al. [29] 2018Case-control study17 tested OA subjects evaluated with deep CNN on 3D images17 age and sex-matched control subjects without OAOMFSDeep neural network classifier of 3D condylar morphology (ShapeVariationAnalyzer, SVA), and a flexible web-based system for data storage, computation and integration (DSCI) of high dimensional imaging, clinical, and biological dataNADeep neural network is a useful tool for classification of TMJOA
Sorkhabi and Khajeh [43] 2019Clinical trial3D deep CNN and CBCTPostextraction clinical parameter measurementsOD and implant dentistry3D CNN method was used to measure alveolar bone density on CBCT images6 months3D deep CNN technique can accurately classify alveolar bone. Pattern, which is helpful in dental implant placement and diagnosis

NA: not applicable; NM: not mentioned; OMFS: oral and maxillofacial surgery; OM: oral medicine; OP: oral pathology; OR: oral radiology; OD: oral diagnosis; AL: apical lesion; CNN: convolutional neural networks; ANN: artificial neural networks; 3D: three dimensional; DL: deep learning; CAL: computer-assisted learning; CAD/CAM: computer-aided design/computer-aided manufacturing; 2D: two dimensional; TMJOA: temporomandibular joint osteoarthritis; OA: osteoarthritis; BPNN: back-propagation neural networks; CDS: clinical decision support systems; BRONJ: bisphosphonate-related osteonecrosis of the jaw; LB-ABC: logit-based artificial bee colony optimization algorithm; VGG-16: Visual Geometry Group; PA: periapical radiograph; CBCT: cone-beam computerized tomography; GA: genetic algorithm; serum CTX: serum C-terminal telopeptide; AUC: area under the curve.