Dental implant surface temperatures following double wavelength (2780/940 nm) laser irradiation in vitro

The Use of 810 and 1064 nm Lasers on Dental Implants: In Vitro Analysis of Temperature, Surface Alterations, and Biological Behavior in Human Gingival Fibroblasts

Objective: The primary objective of this study was to evaluate the safety of 810 and 1064 nm laser treatment on dental implants. Background: Peri-implantitis is a challenge for clinicians and researchers. Methods: A pig mandible model was used to evaluate temperature increases during laser irradiation. Surface alterations on processed pure titanium discs were analyzed via scanning electron microscopy and measurement of surface contact angles. Processed titanium discs were cocultured in vitro with human gingival fibroblasts; subsequently, cell proliferation was measured. Results: The maximum temperature and time to reach each threshold were comparable. No surface alterations were detected after 810 nm laser irradiation, whereas surface cracks were observed after 1064 nm laser irradiation under the parameter setting of 31.84 W/cm2. Compared with unaltered processed pure titanium discs, the proliferation of human gingival fibroblasts was significantly greater on altered processed pure titanium discs. Conclusions: The use of either 810 or 1064 nm laser treatments may increase the risk of thermal damage in terms of increased temperature if the parameter setting is not warranted. In addition, the use of 1064 nm laser treatment could lead to changes in pure titanium discs that do not negatively affect cell proliferation. Further investigations of laser-assisted therapy are necessary to improve guidelines concerning the treatment of peri-implantitis. Clinical trial registration number: 2021-P2-098-01.

Dental implant surface morphology, chemical composition, and topography following double wavelength (2780/940 nm) laser irradiation. An in vitro study

OBJECTIVE

The aim of this in vitro study was to evaluate morphology alterations, chemical composition, and topography of moderately rough dental implants following double-wavelength laser irradiation.

MATERIAL AND METHODS

Commercial-grade titanium dental implants representing different surface characteristics (Osseospeed [OS], TiUnite [TiU], and Roxolid SLActive [RS]) were used. Laser irradiation was performed using a computer-controlled robotic device with calibrated energy/power settings and deionized water spray. Micro-, nano-morphology surface alterations, chemical composition, and surface topography (S_a , S_ds , S_dr ) in the test group (laser plus water), control group A (water only), and control group B (no treatment) were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and white light laser profilometer (Interferometry).

RESULTS

SEM-evaluation revealed minor between-group differences in micro- and nano-morphology within each implant system. Significant overall differences in surface element content were observed between the test and control group B for all implant systems (p < .05). For the test compared with control group B, statistically significantly higher oxygen content was detected for OS and RS (p < .05), a corresponding significant difference was detected for carbon for TiU (p < .05). For RS, a significantly lower content of titanium and zirconium was detected within the test group (p < .05). A significant difference in topography between test and control group B was observed for OS (S_a : p = .039 and S_dr : p = .041) with the highest roughness value for control group B.

CONCLUSIONS

Altered chemical composition and surface topography were observed for all implant surfaces compared with untreated control following double wavelength laser irradiation. A clinical evaluation of the impact of the altered surface composition following double wavelength laser irradiation on the ability to reosseointegrate appears warranted.

Investigation of Topographical Alterations in Titanium-Zirconium-Alloy Implant Threads following Er:YAG Irradiation

The aim of the current experimental study was to comparatively assess the surface alterations in titanium and titanium-zirconium alloy implants in terms of thread pitch topography after irradiation with an Er:YAG laser, which is recommended in the literature for its sterilizing effect in the treatment of contaminated implant surfaces. Roxolid^® and SLA^® (Sand-blasted, Large-grit, Acid-etched) implants from Straumann^® company with the same macro topography were investigated. The surface treatment was carried out using a wavelength of 2940 nm, 60 s irradiation time, a frequency of 10 Hz, and energies between 120 mJ and 250 mJ. The alterations were quantitatively analyzed by conducting roughness analysis via white light interferometry and qualitatively using SEM images. Roxolid^® could particularly maintain its surface topography at a level of 160 mJ. At an energy level of 250 mJ, the surface properties of the pitch could be significantly altered for the first time. Compared to the Standard Plus dental implants studied, no distinct removal of the material from the surface was detected. The alloy properties of Roxolid^® confirm the manufacturer's statement in terms of stability and could offer advantages in peri-implantitis management if decontamination has been selected. However, as a part of a respective strategy, smoothening of a Roxolid^® implant surface requires a significantly higher energy level compared to SLA-Standard^® dental implants.

Dental implant surface temperatures following double wavelength (2780/940 nm) laser irradiation in vitro

Objective

To estimate the implant surface temperature at titanium dental implants during calibrated irradiation using double wavelength laser.

Material and methods

A double wavelength laser, 2780 nm Er,Cr:YSGG and 940 nm diode, was calibrated and used to irradiate pristine titanium dental implants, OsseoSpeed, TiUnite and Roxolid SLActive, representing different surface modifications. Initial calibration (21 implants; 7 implants/group) intended to identify optimal wavelength/specific output power/energy that not critically increased the temperature or altered the micro‐texture of the implant surface. Subsequent experimental study (30 implants; 10 implants/group) evaluated implant surface temperature changes over 190 s. Irradiation using a computerized robotic setup.

Results

Based on the initial calibration, the following output powers/energies were employed: Er,Cr:YSGG laser 18.4 mJ/pulse (7.3 J/cm²)–36.2 mJ/pulse (14.4 J/cm²) depending on implant surface; diode laser 3.3 W (1321.0 W/cm²). During double wavelength irradiation, implant surface temperatures dropped over the first 20 s from baseline 37°C to mean temperatures ranging between 25.7 and 26.3°C. Differences in mean temperatures between OsseoSpeed and TiUnite implants were statistically significant (p < 0.001). After the initial 20 s, mean temperatures continued to decrease for all implant surfaces. The decrease was significantly greater for TiUnite and Roxolid SLActive compared with OsseoSpeed implants (p < 0.001).

Conclusion

Calibrated double wavelength laser irradiation did not critically influence the implant surface temperature. During laser irradiation the temperature decreased rapidly to steady‐state levels, close to the water/air‐spray temperature.