Table 2.

Study characteristics of included studies.

Study ID	Place of Study	Sample Size Teeth/Patient	Age Range (Years)	Pathology of Teeth	Type of Teeth	Pulp Vitality Tests	Pulp Sensibility Tests	Authors’ Conclusions
Gopikrishna et al., 2007 [7]	India	80/80	Not reported	Requiring endodontic therapy for prosthodontic considerations or for irreversible pulpitis	Single-rooted incisors, canines and premolars	PO	CT EPT	Custom-built pulse oximeter dental probe is an effective, accurate and objective method of determining the vitality of permanent teeth.
Karayilmaz and Kirzioğlu, 2011 [10]	Turkey	59/51	12–18	Root canal treated	Maxillary anterior teeth	LDF PO	EPT	LDF was found to be a more reliable and effective method than PO and EPT for assessing the pulpal status of human teeth.
Dastmalchi et al., 2012 [11]	Iran	24/24	18–50	Requiring endodontic treatment for prosthodontic reasons	Single-canal mandibular premolars	PO	CT HT EPT	PO is a reliable method in determining the actual status of the pulp in endodontics; however, CT, HT and EPT are not suitable methods for pulp testing.
Janani et al., 2020 [12]	India	79	18–56	Requiring endodontic therapy	Single-rooted teeth	PO	CT HT EPT	Customized pulse oximeter sensor holder proves to be accurate, reliable and objective in assessing the actual condition of the tooth.
Chen and Abbott, 2011 [16]	Australia	121/20	18–74	Suspected or known to have pulp pathosis; previously received or currently undergoing endodontic treatment; or provisionally diagnosed as having a healthy pulp	Not reported	LDF	CT EPT	Carbon dioxide (CO2) crystals, EPT and LDF were reliable and the most accurate tests, but CO2 and EPT were less repeatable yet less time consuming than LDF.
Samuel et al., 2014 [25]	India	120/30	7–18	Free of any dental pathology	Permanent maxillary central and lateral incisors	PO	CT EPT	In young children, PO method was found to be as accurate as cold test but large variations were seen in electric pulp test.
Condit, 2015 [26]	Columbus, US	85	6–16	Traumatized teeth	Maxillary central and lateral incisors	LDF	CT EPT	LDF could not distinguish between healthy and necrotic pulp tissue among traumatized teeth.
Sharma et al., 2015 [27]	India	Not reported	4–15	Requiring endodontic therapy	Not reported	PO	EPT	PO is an objective, very sensitive and noninvasive method that can be used as a routine method for assessing the pulp vitality in primary, young permanent and mature permanent teeth.
Ghouth et al., 2019 [28]	UK	37	8–16	Root canal treated	Permanent anterior teeth	LDF	CT EPT	LDF was unable to differentiate between teeth with vital and nonvital pulps in children between the ages of 8 and 16 years, with an acceptable level of confidence.
Ajitha et al., 2020 [29]	India	30	18–50	Requiring endodontic therapy indicative of irreversible pulpitis	Single-canal incisors, canine and mandibular premolar teeth	PO	CT HT EPT	The use of custom-made holder is effective in placement of sensor probe onto the tooth surface. It aided in evaluating the actual pulp status by producing accurate interpretation of results.