Compiled by Dr Igor Cernavin, Prosthodontist, Honorary Senior Fellow University
of Melbourne School of Medicine, Dentistry and Health Sciences, Director and
Cofounder of the Asia Pacific Institute of Dental Education and Research (AIDER),
Australian representative of World Federation of Laser Dentistry (WFLD).
Weber et al1 present an interesting study on the
thyroid gland function and consequently, calcium
serum triiodothyronine (T3), thyroxine (T4), and
when administered after dental implant placement
effects of LLLT on
regulation as measured by
free calcium levels in a rabbit model.
Forty male adult New Zealand rabbits were distributed across five groups
of eight animals each: two control groups (C-I and C-II) of unirradiated
animals, and three experimental groups (E-5, E-10, and E-20), each exposed
to a distinct dose of gallium-aluminum-arsenide (GaAlAs) laser
[lambda=830nm, 50mW, continuous wave (CW)] every 48h for a total of seven
sessions. The total dose per session was 5 J/cm(2) in E-5, 10J/cm(2) in E10, and 20J/cm(2) in E-20. Animals in C-II and all experimental groups
underwent surgical extraction of the mandibular left incisor followed by
immediate placement of an osseointegrated implant (Nanotite), Biomet 3i
into the socket. Animals in group C-I served as an absolute control for
T3, T4, and calcium measurements. The level of significance was set at 5%
(p≤0.05). RESULTS: ANOVA with Tukey's post-hoc test revealed significant
differences in T3 and calcium levels among experimental groups, as well as
significant within-group differences in T3, T4, and calcium levels over
time. CONCLUSIONS: Although not reaching abnormal values, LLLT applied to
the mandible influenced thyroid function in this model.
Sousa and coworkers2 carried out a review of the literature to check the influence of lowlevel laser (LLL) on orthodontic movement and pain control in humans, and what dose
ranges are effective for pain control and increased speed of orthodontic movement. .
They found that the most common and effective energy input was the interval of 0.2-2.2J
per point/2-8J per tooth at a frequency of application 1-5 days per month to accelerate the
orthodontic movement. For pain control, the recommended energy per points varied from
1-2J when only one tooth was irradiated to 0.5-2.25J per point when all teeth in the dental
arch were irradiated.
Ierardo et al3 compared the use of Er:Yag laser with phosphoric acid for bonding of
orthodontic brackets and found no advantage with the use of laser.
Porcaro4 and coworkers presented a new therapeutic approach combining
fluorescence-guided Er:YAG laser ablation with Nd:YAG/diode laser
biostimulation for bisphosphonate-related osteonecrosis of the jaw
(BRONJ). The case is presented as published.
A woman was treated with zoledronic acid for bone metastasis from clear
cell renal cell carcinoma and subsequently developed BRONJ in the left
jaw. The management protocol included perioperative medical therapy (1%
chlorhexidine gel, rifamycin, and doxycycline for 10 preoperative and 7
postoperative days), Er:YAG laser ablation guided by doxycycline
fluorescence in vital bone under UV light, and Nd:YAG/diode laser
biostimulation. The lesion regressed from stage 3 to stage 1 and showed
nearly complete healing after laser therapy (3 and 23 cycles of ablation
and biostimulation, respectively). These preliminary findings suggest the
feasibility of the new approach, which is minimally invasive and
biostimulative and causes very low morbidity. Tell your oral surgery
mates!!
Maenosono et al5 found that diode laser irradiation increases microtensile
bond strength of dentine. The abstract is reproduced in full.
Laser irradiation after the immediate application of dentin bonding
systems (DBSs) and prior to their polymerization has been proposed to
increase bond strength. The objective of this study was to evaluate the
effect of diode laser irradiation (lambda = 970 nm) on simplified DBSs
through microtensile bond strength tests. Forty healthy human molars were
randomly distributed among four groups (n = 10) according to DBSs used
[Adper SingleBond 2 (SB) and Adper EasyOne (EO)], and the respective
groups were irradiated with a diode laser (SB-L and EO-L). After bonding
procedures and composite resin build-ups, teeth were stored in deionized
water for 7 days and then sectioned to obtain stick-shaped specimens (1.0
mm2). The microtensile test was performed at 0.5 mm/min, yielding bond
strength values in MPa, which were evaluated by two-way ANOVA followed by
Tukey's test (p < 0.05) for individual comparisons. For both adhesive
systems, diode laser irradiation promoted significant increases in bond
strength values (SB: 33.49 ± 6.77; SB-L: 43.69 ± 8.15; EO: 19.67 ± 5.86;
EO-L: 29.87 ± 6.98). These results suggest that diode laser irradiation is
a promising technique for achieving better performance of adhesive systems
on dentin.
Miremadi6 carried out an experimental clinical trial aimed to determine the
effects of debridement using Er:YAG laser and to compare it with
ultrasonic treatment.
They found that Laser debridement produced an irregular, rough and flaky
surface free of carbonization or meltdown while ultrasound produced a
relatively smoother surface. The number of exposed dentinal tubules
followed an energy-dependent trend. The number of exposed tubules among
the in vivo laser groups was n 60 mJ = n 100 mJ < n 160 mJ < n 250 mJ (P <
0.001). Also 160 and 250 mJ lasers led to significantly more dentinal
exposure than ultrasound under in vivo condition. Within the in vitro
laser groups, dentinal tubules exposure was n 60 mJ < n 100 mJ < n 160 mJ
< n 250 mJ (P ≤ 0.0015). Furthermore, in vitro laser treatments at 100,
160 and 250 mJ led to significantly more dentinal denudation than
ultrasound. Treatment duration (d) for the in vivo groups was d 60 mJ > d
100 mJ > d Ultrasound = d 160 mJ > d 250 mJ (P ≤ 0.046), while for the in
vitro groups it was d 60 mJ > d 100 mJ = d Ultrasound = d 160 mJ >d 250 mJ
(P ≤ 0.046).CONCLUSIONS: Due to excessive treatment duration and surface
damage, Er:YAG laser debridement at 60 and 250 mJ pulse(-1), respectively,
is not appropriate for clinical use. Although laser debridement at 100 and
160 mJ/pulse seems more suitable for clinical application, compared to
ultrasound, the former is more time-consuming and the latter is more
aggressive. Using a feedback device or lower pulse energies are
recommended when using laser in closed field.
Geraldo-Martins and coworkers7 examined the combined use of Er,Cr:YSGG
laser and fluoride to prevent root dentin demineralization. They found
that the use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2
without water cooling with 2% NaF can increase the acid resistance of
human root dentin.
Praveen Arany8 writes an interesting article on the possibility of lasers
leading the way in regenerative dentistry in the year, 2015, being the
year of light. In the current era of personalized medicine and strategies
to utilize sophisticate technologies and pharmaceuticals to individualise
health care, lasers may be the pivotal technology which ushers in a new
era of regenerative dentistry.
References
1. Weber, Joao Batista Blessmann; Mayer, Luciano; Cenci, Rodrigo
Alberto; Baraldi, Carlos Eduardo; Ponzoni, Deise; Gerhardt de
Oliveira, Marilia. 1. Effect of three different protocols of lowlevel laser therapy on thyroid hormone production after dental
implant placement in an experimental rabbit model. Photomedicine and
laser surgery, 32 (11):612-7; 10.1089/pho.2014.3756 2014-Nov.
2. Sousa, Marines Vieira S; Pinzan, Arnaldo; Consolaro, Alberto;
Henriques, Jose Fernando Castanhas; de Freitas, Marcos Roberto.
Photomedicine and laser surgery, 32 (11):592-9;
10.1089/pho.2014.3789 2014-Nov.
3. Ierardo, G; Di Carlo, G; Petrillo, F; Luzzi, V; Vozza, I; Migliau,
G; Kornblit, R; Rocca, J P; Polimeni, A. Er:YAG Laser for Brackets
Bonding: A SEM Study after Debonding. TheScientificWorldJournal,
2014 935946; 10.1155/2014/935946 2014.
4. Porcaro, Gianluca; Amosso, Ernesto; Scarpella, Rita; Carini,
Fabrizio. Doxycycline fluorescence-guided Er:YAG laser ablation
combined with Nd:YAG/diode laser biostimulation for treating
bisphosphonate-related osteonecrosis of the jaw. Oral surgery, oral
medicine, oral pathology and oral radiology, 119 (1):e6-e12;
10.1016/j.oooo.2014.04.014 2015-Jan.
5. Maenosono, Rafael Massunari; Bim Junior, Odair; Duarte, Marco
Antonio Hungaro; Palma-Dibb, Regina Guenka; Wang, Linda;
Ishikiriama, Sergio Kiyoshi. Diode laser irradiation increases
microtensile bond strength of dentin. Brazilian oral research, 29
(1):1-5; 2015.
6. Miremadi, S R; Cosyn, J; Schaubroeck, D; Lang, N P; De Moor, R J G;
De Bruyn, H. Effects of root surface debridement using Er:YAG laser
versus ultrasonic scaling - a SEM study. International journal of
dental hygiene, 12 (4):273-84; 10.1111/idh.12074 2014-Nov.
7. Geraldo-Martins, Vinicius Rangel; Lepri, Cesar Penazzo; FaraoniRomano, Juliana Jendiroba; Palma-Dibb, Regina Guenka. The combined
use of Er,Cr:YSGG laser and fluoride to prevent root dentin
demineralization. Journal of applied oral science : revista FOB, 22
(5):459-64; 2014-Oct.
8. Aranyi Praveen R. Innovations with lasers could lead regenerative
dentistry. Laser international magazine of laser dentistry. 06-09.
Vol6 Issue 4/2014.