Table 2.: Summary of various studies performed comparing the efficacy of calculus removal using Erbium laser and conventional methods.

Author and Year Study groups and Methodology Findings and Conclusion
Aoki A et al.
2000 [27]
53 periodontally compromised teeth
Ultrasonic scaling Vs Erbium Laser (40 mJ per pulse and 10 pulses under water spray)
Laser scaling provided a level of calculus removal that was similar to that provided by the ultrasonic scaling.
The Er:YAG laser produced superficial, structural and thermal microchanges on the root cementum.
Schwarz F et al. 2001 [28] Forty single rooted teeth
Ultrasonic scaling Vs Erbium Laser (120 mJ, 140 mJ, 160 mJ, 180 mJ at 10 Hz)
Er:YAG laser resulted in a smooth root surface morphology, even at higher energy settings. The results also seem to indicate that calculus removal can be selectively done in vivo
Frentzen M et al. 2002 [29] 40 extracted teeth
Ultrasonic scaling Vs Er YAG Laser (160mJ/pulse, 10 Hz.)
Laser scaling was accompanied by an increased removal of tissue and roughened surfaces.
Laser scaling resulted in an increased loss of cementum and dentin.
Eberhard J et al. 2003 [30] The mesial and distal surfaces of 30 single-rooted teeth with untreated periodontitis were treated either by hand instrumentation (scaling and root planing (SRP)) or by Er:YAG laser irradiation (160 mJ, 10 to 15 Hz) Following laser irradiation, 68.4±14.4% of the root surface was calculus free in contrast to 93.9±3.7% after SRP when both treatments were performed for the same time (2:15±1:00 min).
The histologic evaluation showed that after SRP 73.2% of root dentin was completely denuded from cementum, while only a minimal cementum reduction was apparent after laser irradiation.
Schwarz F, et al. 2006 [31] 72 single-rooted teeth (n=12 patients) were randomly treated in vivo by a single course of subgingival instrumentation using (1-3) an Er: YAG laser (ERL1: 100 mJ; ERL2: 120 mJ; ERL3: 140 mJ; 10 Hz), or (4) the Vector ultrasonic system (VUS) or (5) hand instruments (SRP). Highest values of Residual subgingival calculus areas (RSC) (%) were observed in the SRP group (12.5±6.9). ERL (1-3) (7.8±5.8, 8.6±4.5, 6.2±3.9, respectively) revealed significantly lower RSC areas than SRP. VUS (2.4±1.8) exhibited significantly lower RSC areas than SRP and ERL (1, 2).
Moghare Abed A
et al. 2007 [32]
The mesial and distal surfaces of 15 periodontally loose extracted teeth were treated randomly either by hand instrumentation or by Er:YAG laser irradiation. (160 mJ, 12 Hz) The surface roughness in Er: YAG laser group was more than in hand instruments group.
Lower frequency and long pulse duration maybe more suitable for the micro-morphology of root surface after treatment.
Krause F et al. 2007 [33] 20 teeth were treated with an Er: YAG laser. Laser settings were 140 mJ and 10 Hz. The amount of residual calculus following laser irradiation depends on the fluorescence threshold level for a feedback-controlled Er: YAG laser.
Ting CC et al. 2007 [34] 65 non carious teeth were prepared and divided randomly into three groups: a control group (N=8), irradiation without water group (no water [NW] group; N=39), and an irradiation in water group to simulate the conditions in a periodontal pocket group (in water [IW] group; N=44). The power output settings for Erbium laser irradiation were 0.5, 1.0, 1.5, and 2.0 W for each group. Mean Ra and Z values in the IW group were significantly higher than in the NW group with the same power output.
Thermal alterations were completely absent in the IW group. With regard to efficiency of calculus removal, the 0.5 W setting (0.11±0.036 mm2/second) was significantly inferior to the 1.0-W setting (0.27±0.043 mm2/second). The 2.0-W setting (0.63±0.272 mm2/second) was much more efficient but resulted in significant morphologic alterations.
Hakki SS
et al. 2010 [35]
32 single-rooted teeth were treated by different methods including (1) conventional hand instruments; (2) hand instruments and tetracycline-hydrochloride (Tet-HCl); (3) erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation, setting I (short pulse); (4) Er,Cr:YSGG laser irradiation, setting II (long pulse). Roughness was greater in the long-pulse laser setting than in the short-pulse setting.
All treatments were equally efficient in calculus removal from the root surfaces.
Oliveira GJ et al. 2012 [36] 60 teeth samples were divided into 3 groups (20 each)
Group 1: Control (G1).
Group 2: Er Cr YSGG laser irradiation (G2).
Group 3: Er YAG laser irradiation (G3).
Out of the 20 samples in each group, 10 samples received blood application. Root surface changes and blood component adhesion was assessed by Scanning Electron Microscope (SEM).
Teeth treated with Er: YAG and Er Cr YSGG lasers demonstrated greater root surface roughness than those in the control group. Er YAG laser treatment allowed a greater degree of blood component attachment as compared to exposure to Er Cr YSGG laser.
Alhmedi A et al. 2013 [37] A comparison of cementum alterations following treatment with Er YAG and CO2 laser using non de-calcified thin histologic sections was done. Parameters were as follows:
1. Er YAG laser was used with the following parameters 40 mg/ pulse (14.2J/cm2/ pulse) and 25 HZ (1.0W) under water spray.
2. Co2 laser irradiation was performed in non contact mode at 1.0 W
3. Ultrasonic scaling was used a control group.
Er YAG treatment group demonstrated micro-irregularities with whitish slightly ablated surface and thermal changes up to 20 microns. In Co2 laser group a carbonization and thermal changes up to 140 microns thickness was observed. The authors concluded that Er YAG laser with water cooling resulted in minimal thermal damage.