scholarly journals Using 445 nm and 970 nm Lasers on Dental Implants—An In Vitro Study on Change in Temperature and Surface Alterations

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3934
Author(s):  
Sebastian Malmqvist ◽  
Anders Liljeborg ◽  
Talat Qadri ◽  
Gunnar Johannsen ◽  
Annsofi Johannsen

The aim of this study was to evaluate the safety of using a 445 nm laser on dental implants by comparing it with a laser with 970 nm wavelength. Two models, a pig mandible and glass ionomer cement, were used to evaluate the temperature increase in dental implants during laser irradiation with both wavelengths. Temperature was measured every second at four different places on the dental implants. Different power settings, effects of water cooling, distance of the laser fibre to the dental implant and continuous comparison to a pulsed laser beam were tested. Surface alterations on titanium discs after laser irradiation for 4 min at 2.0 W, were analysed in a scanning electron microscope (SEM). The maximum temperature and time to reach each of the thresholds were comparable between the 445 nm and 970 nm lasers. Neither the 445 nm nor the 970 nm wavelength showed any signs of surface alterations on the titanium discs. Using a 445 nm laser on dental implants is as safe as using a 970 nm laser, in terms of temperature increase and surface alterations. Applying a generous amount of cooling water and irradiating in short intervals is important when using lasers on dental implants.

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1700
Author(s):  
Atsushi Kameyama ◽  
Aoi Saito ◽  
Akiko Haruyama ◽  
Tomoaki Komada ◽  
Setsuko Sugiyama ◽  
...  

This study aimed to examine the marginal seal between various commercial temporary restorative materials and exposed dentin/built-up composite. Sixty bovine incisors were cut above the cemento-enamel junction, and half of the dentin was removed to form a step, which was built up using flowable resin composite. The root canals were irrigated, filled with calcium hydroxide, and sealed using one of six temporary sealing materials (hydraulic temporary restorative material, temporary stopping material, zinc oxide eugenol cement, glass-ionomer cement, auto-cured resin-based temporary restorative material, and light-cured resin-based temporary restorative material) (n = 10 for each material). The samples were thermocycled 500 times and immersed in an aqueous solution of methylene blue. After 2 days, they were cut along the long axis of the tooth and the depth of dye penetration was measured at the dentin side and the built-up composite side. For the margins of the pre-endodontic resin composite build-up, the two resin-based temporary restorative materials showed excellent sealing. Hydraulic temporary restorative material had a moderate sealing effect, but the sealing effect of both zinc oxide eugenol cement and glass-ionomer cement was poorer.


2013 ◽  
Vol 37 (4) ◽  
pp. 403-406 ◽  
Author(s):  
S Tamilselvam ◽  
MJ Divyanand ◽  
P Neelakantan

Objective: This aim of this study was at compare the fibroblast cytotoxicicty of four restorative materials - a conventional glass ionomer cement (GC Fuji Type II GIC), a ceramic reinforced glass ionomer cement (Amalgomer), a giomer (Beautifil II) and a resin composite (Filtek Z350) at three different time periods (24, 48 and 72 hours). Method: The succinyl dehydrogenase (MTT) assay was employed. Cylindrical specimens of each material (n=15) were prepared and stored in Dulbecco's modified Eagle medium, following which L929 fibroblasts were cultured in 96 well plates. After 24 hours of incubation, the MTT assay was performed to detect the cell viability. The method was repeated after 48 and 72 hours. The impact of materials and exposure times on cytotoxicity of fibroblasts was statistically analyzed using two way ANOVA (P=0.05). Results: Both time and material had an impact on cell viability, with giomer demonstrating the maximum cell viability at all time periods. The cell viability in the giomer group was significantly different from all other materials at 24 and 72 hours (P<0.05), while at 48 hours giomer was significantly different only with resin composite (P<0.05). Conclusions: Giomers showed better biocompatibility than conventional and ceramic reinforced glass ionomer cements and, resin composite. Ceramic reinforced glass ionomer demonstrated superior biocompatibility compared to conventional glass ionomer.


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