Study suggests that a computer program may have some success in managing patients with dental needle fear


Significant fear of dental injections has been reported in as many as one in four adults.   The aim of this study was to compare the efficacy of  Computer Assisted Relaxation
 Learning (CARL) with an informational pamphlet for reducing dental injection fear. CARL is a self-paced, computerized program based on systematic desensitization aimed at reducing fear of dental injections (Coldwell et al 1998, 2007)

Patients reporting fear and avoidance of dental injections were recruited through newspaper advertisements in the communities of 8 participating dental practices. Patients completed a baseline assessment using the following measures; Modified Dental Anxiety Scale (MDAS); Dental Fear Survey (DFS); The Needle Survey (NS). They were then randomised to either CARL or pamphlet intervention. On completion of either protocol, participants again completed the MDAS; DFS & NS measures and were offered the opportunity to receive an optional dental injection. Patients received a $10 gift voucher for completing the baseline evaluation and on completion of the protocol

  • 84 individuals (65.5% female) were randomized separately within each dental practice to either CARL (n=41) or pamphlet (n=43).
  • 68 participants completed the study (34 CARL, 34 pamphlet)
  • Participants completing CARL reported significantly greater reduction in self-reported general and injection-specific dental anxiety measures compared with control individuals (p < .001).
  • Twelve of 34 (35.3%) CARL participants received injections, while six of 34 (17.6%) pamphlet participants received injections.

The authors concluded

CARL, a computerised therapeutic protocol, was successful in reducing self-reported dental fear related to dental injections compared with an informational standard of care. Since CARL does not require involvement by trained therapists or special training for dentists, it may increase access to this therapeutic approach to a wider proportion of the population, improving access to dental care and better oral health overall.


More details of the CARL program are provided in an appendix to the article. It takes place in a session of up to 45 minutes and includes 9 video segments an the opportunity to ask a dental staff member about issues reviewed in the CARL program.  In the discussion the authors highlight another online programme the FearFighterTM Panic and Phobia Treatment modality which has been endorsed by NICE (National Institute for Health and Care Excellence).

It is worth noting that only 21% patients originally randomised returned for the optional dental injection which as the authors indicate is a significant outcome of interest in this type of study.  It would be interesting to see the CARL program compared to another therapy rather than a pamphlet.


Heaton LJ, Leroux BG, Ruff PA, Coldwell SE. Computerized Dental Injection Fear Treatment: A Randomized Clinical Trial. J Dent Res. 2013 May 20. [Epub ahead of print] PubMed PMID: 23690352.

Coldwell SE, Wilhelm FH, Milgrom P, Prall CW, Getz T, Spadafora A, Chiu IY, Leroux BG, Ramsay DS. Combining alprazolam with systematic desensitization therapy for dental injection phobia. J Anxiety Disord. 2007;21(7):871-87. Epub 2007 Jan 23. PubMed PMID: 17320345.

Coldwell SE, Getz T, Milgrom P, Prall CW, Spadafora A, Ramsay DS. CARL: a LabVIEW 3 computer program for conducting exposure therapy for the treatment of dental injection fear. Behav Res Ther. 1998 Apr;36(4):429-41. PubMed PMID: 9670603.

FearFighter for panic and anxiety

NICE :National Institute for Health and Care Excellence




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Derek Richards

Derek Richards is a specialist in dental public health, Director of the Centre for Evidence-Based Dentistry and Specialist Advisor to the Scottish Dental Clinical Effectiveness Programme (SDCEP) Development Team. A former editor of the Evidence-Based Dentistry Journal and chief blogger for the Dental Elf website until December 2023. Derek has been involved with a wide range of evidence-based initiatives both nationally and internationally since 1994. Derek retired from the NHS in 2019 remaining as a part-time senior lecturer at Dundee Dental School until the end of 2023.

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