Third molar surgery – Er:Yag lasers and post-operative problems


The removal of the impacted third molar is a very common surgical procedure with typical post-operative problems of pain, swelling, and trismus. Some studies have suggested that the use of lasers may lead to reduced complications, The use of the erbium: yttrium aluminum garnet (Er: YAG) laser for the removal of impacted third molars was first reported in 2004.

The aim of this review was to compare to the effectiveness of Er: YAG lasers in reducing pain, oedema and trismus compared to rotary instruments for the removal of impacted lower third molars.


The review was registered on PROSPERO and searches conducted in the Pubmed/Medline, Scopus, LILACS, Cochrane Central and Open Gray databases with no language restrictions. Two reviewers independently conducted the searches data abstracted and risk of bias assessed using the Cochrane RoB 2 tool. Randomised controlled trials (RCTs) of Er:Yag lasers for the removal of impacted mandibular third molars were considered. The main outcomes were post-operative pain, oedema, and trismus and a random effects meta-analysis was conducted.


  • 6 RCTs involving a total of 250 patients were included
  • 299 third molars were extracted ,126 with Er:YAG laser, 142 with a drill, and 31 with a piezoelectric instrument.
  • With the exception of 1 study of 15 days follow up period was 7 days.
  • 2 studies had a high risk of bias, one a low risk with 3 having some concerns.
  • 3 studies reported 37 complications that were more frequent in the drill group
  • Meta-analyses were conducted for pain (3 studies), Swelling (4 studies) and trismus (4 studies) as shown in the tables below.
Post-operative pain Standard mean difference (95%CI)
1 day 0.03 (-0.42 to 0.47)
2 days -0.41 (-0.79 to -0.04)
7 days 0.04 (-0.32 to 0.40)
Overall -0.14 (-0.38 to 0.10)


Swelling Mean difference (95%CI)
Tragus – Angle of mouth Gonion – Corner of the eye
2 days -3.23 (-4.65 to -1.81) -4.32 ( -5.99 to -2.66)
7 days -0.91 (-1.86 to 0.03) -0.33 (-3.36 to -0.25)
Overall -1.82 (-3.06 to -0.57) -1.80 (-3.36 to -0.25)


Trismus Mean difference (95%CI)
2 days -3.58 (-10.62 to 3.45)
7 days -1.04 (-5.55 to 3.47)
Overall -2.29 (-5.76 to 1.18)
  • Analysis showed a statistically significant reduction in pain with lasers at 2 days post op only.
  • A statistically significant benefit in favour of lasers was seen for swelling at the tragus and gonion at 2 days and for the gonion at 7 days.
  • No significant differences were seen for trismus.


The authors concluded: –

…the Er: YAG laser showed an important reduction in oedema and complications, a slight reduction in pain, and showed no difference in relation to trismus in the removal of impacted lower third molars. New controlled studies with standardised energy protocols must be performed in order to accurately determine the safety and efficacy of using the Er: YAG laser in the removal of impacted lower third molars.


The authors have searched a good range of databases with no language restrictions. However, only 6 studies could be included, and they are mainly small in size with only one RCT being at low risk of bias. In total 126 lower third molars were extracted using the Er:Yag laser with no reported bone or soft tissue necrosis While the findings indicate a small reduction in pain and oedema at certain time points there is a question about how important this is from the clinician and patient perspective. This review focusses on extractions using lasers in a review we previously considered by Domah et al (Dental Elf – 15th Mar 2021)  the use of low-level lasers was also shown to reduce swelling but not pain or trismus. The Domah review like this current review was hampered by only being able to include mainly small studies of limited quality. Future studies need to be well designed conducted and reported in line with SPIRIT and CONSORT guidelines preferably using common outcomes sets (COMET) to provide higher quality evidence on the use of lasers in third molar surgery


Primary Paper

Sales PHDH, Barros AWP, Silva PGB, Vescovi P, Leão JC. Is the Er: YAG Laser Effective in Reducing Pain, Edema, and Trismus After Removal of Impacted Mandibular Third Molars? A Meta-Analysis. J Oral Maxillofac Surg. 2021 Oct 20: S0278-2391(21)01241-6. doi: 10.1016/j.joms.2021.10.006. Epub ahead of print. PMID: 34793714.

Review protocol on PROSPERO

Other references

Dental Elf – 15th Mar 2021

Third molar surgery: Does low-level laser therapy reduce post-operative morbidity?

Dental Elf – 5th Aug 2020

Third molars: Which surgical technique for removal?



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