Use of laser Doppler flowmetry to predict vitality of luxated or avulsed permanent teeth

Objective Splinting of traumatically displaced or avulsed permanent teeth has been described as an effective modality in the treatment of patients with dental injuries. The purpose of this study was to investigate whether laser Doppler flowmetry (LDF) measurements of pulpal blood flow (PBF) and/or dental injury type may predict treatment outcome of splinting of permanent maxillary incisors. Study design The study comprised 64 patients undergoing dental trauma splinting, who were characterized by the presence of a single permanent maxillary incisor affected by a subluxation, luxation, or avulsion type injury. Perfusion units (PU) were taken in 2 sessions, on the day of splint removal (6 weeks after trauma; session I) and 12 weeks after splint removal (session II). At each session, when an injured permanent maxillary central incisor was recorded, the respective contralateral homologous tooth was used as a control. An adverse outcome occurring 36 weeks after splint removal was defined as the presence of “periapical radiolucency and/or grey discoloration.” A multiple logistic regression analysis was used to compute the odds ratio for session-related PBF characteristics and dental injury type for adverse outcome (n = 22) versus nonadverse outcome (n = 42). Results There was a significant increase in PBF values from session I to session II (P = .047) for teeth without an adverse outcome, whereas teeth affected by an adverse outcome showed a significant decrease in PBF values (P = .001). PBF measurements did not change over time for the control group of contralateral incisors (P = .185). For the outcome criterion of “presence of periapical radiolucency and/or grey discoloration,” there was a significant association between the treatment outcome groups and the variables of dental injury type (P = .049), session-related PBF difference (P = .000), and session II–related PBF level (P = .000). Significant increase in risk of an adverse outcome occurred with a session-related PBF difference (PBFSession I − PBFSession II) of ≥0 PU (8.6 odds ratio) (P = .014), and a session II–related PBF level of ≤2.8 PU (20.2 odds ratio) (P = .030). Conclusion The data suggest the LDF test to be a valuable diagnostic adjunct for luxated teeth showing signs of adverse outcomes. Predictive modeling may provide clinicians with the opportunity to identify “at-risk” teeth early and initiate specific treatments.