Introduction: The use of hypnosis has been increasingly advocated in oral surgery to obtain sedation and decrease pain perception, but no data are so far available on dental pain threshold. The aim of this study was to check at which extent hypnosis and hypnotic focused analgesia (HFA) may increase dental pain threshold in healthy volunteers.
Subjects and methods: 31 healthy subjects (12 males and 19 females, age range 23–50 years) were submitted to hypnosis; HFA was obtained with suggestions of eminattention and analgesia of the right low arch (suggestion of inferior alveolar nerve block). A posthypnotic suggestion of persisting analgesia was also delivered. The pain threshold of the right and left first premolars (RFP and LFP, respectively) was bilaterally measured, using a Digitest (Parker, Farmingdale, USA). The statistical analysis was conducted with Freedman test and Wilcoxon test according to Bonferroni.
Results: The basal pain threshold was 14.6 ± 7.0 mA in the RFP and 13.4 ± 6.6 in the LFP. During hypnosis it increased to 46.7 ± 19.7 (+220%; p < 0.0001) and 31.1 ± 19.9 mA (+132%; p < 0.0001) in RFP and LFP, respectively with a significant difference between the two ( p < 0.001), showing the effectiveness of HFA. The posthypnotic pain threshold was 26.3 ± 17.7 ( p = 0.0015) in RFP and 20.1 ± 16.2 ( p = 0.054) in LFP.
Conclusions: Hypnosis is a powerful non-pharmacologic analgesic tool; its effects on pain threshold are related to both relaxation and distraction, and specific effects of HFA in the target area. The analgesic effect partially persists in the post-hypnotic phase, suggesting that hypnosis might improve postoperative pain as well.
Conflict of interest: None declared.