Comparative evaluation of the antibacterial activity of red diode laser therapy and 0.2% chlorhexidine against Aggregatibacter actinomycetemcomitans on implant healing abutments: An ex vivo study

Abstract

Aims: The intraoral microbiota has a high potential to undergo dysbiosis, causing inflammatory changes with respect to the tissues surrounding either a natural tooth or an implant. Thus, the longevity of implant prosthesis depends on a thorough implant decontamination protocol. Among all the techniques available for doing so, laser is garnering increasing popularity, owing to minimal bleeding, high efficiency, and faster healing. However, limited literature exists regarding the superiority of lasers over chlorhexidine (CHX), the indisputable gold standard antibacterial chemical agent. The aim of this study was to compare the percentage of bacterial reduction of Aggregatibacter actinomycetemcomitans from implant healing abutments post red diode laser therapy versus 0.2% CHX treatment.

Settings and design: The current study had an ex vivo, observational, case-control design.

Materials and methods: Patients reporting for the second stage of the implant surgery were taken as the source of data and the healing abutments, the clinical samples. Eleven patients were chosen with one intraoral implant serving as the test site for laser treatment and another, the control site for CHX treatment. Microbiological analysis was performed via quantitative real time polymerase chain reaction to compare the bacterial reduction percentage after each treatment.

Statistical analysis used: Repeated measures ANOVA and independent sample t test were used.

Results: The mean bacterial viability of the test group (laser) was 1.2%-1.6%, and 0.6%-1.4% for the control group (CHX). The former caused a mean bacterial reduction of 96.1% while the latter, 96.3%. Both the treatments caused a highly statistically significant reduction of viable bacterial counts (P = 0.001). However, when compared, there was no statistically significant difference in the bacterial reduction, when compared in between the two (P = 0.902).

Conclusion: Laser treatment is at par with chemical implant surface decontamination. It can help bypass the complications of CHX and revolutionize the protocols for implant surface decontamination.

Keywords: Chlorhexidine; diode laser; implant surface decontamination.

Figure 1

Clinical sample collection from oral cavity of study subject. (a) Intraoral left lateral view of subject post second-stage surgery of implant placement at two intraoral sites. (b) Removal of the two healing abutments with the implant hex driver. (c) Collection of the two healing abutments into sterile microcentrifuge tubes prior to simple randomization for allotment to test and control groups

Figure 2

Procedure for carrying out laser treatment on test sample. (a) Protocol of laser treatment followed with initial energy output of 0 J/cm² reaching a maximum of 703.125 J/cm² by the end of Phase B for samples from test site undergoing laser treatment. (b) Healing abutment from test site kept stable; dappen dish manually rotated slowly for uniform exposure of laser light to all the surfaces of the healing abutment

Figure 3

Procedure for carrying out chlorhexidine treatment on control sample. (a) Sample from control site submerged in 1 mL of 0.2% chlorhexidine digluconate. (b) After 30 seconds, sample held gently with a sterile bracket holder and washed with water lightly to remove traces of CHX. CHX: Chlorhexidine

Figure 4

The final sample solutions from each patient. Phase A: L_D✓^Ua, L_Dx^Ua, CHX_D✓^Ua, CHX_Dx^Ua. Phase B: L_D✓^Tb, L_Dx^Tb, CHX_D✓^Tb, CHX_Dx^Tb. CHX: Chlorhexidine

Figure 5

Exposure of sample solutions to blue LED light after application of viability dye, PMAxx. LED: Light-emitting diode

Graph 1

Mean VBC of laser and CHX groups before and after treatment. VBC: Viable bacterial count, CHX: Chlorhexidine

Graph 2

Mean BVR of laser and CHX groups before and after treatment. BVR: Bacterial viability ratio, CHX: Chlorhexidine

Graph 3

Mean difference in the bacterial reduction percentage between laser and CHX treatments. CHX: Chlorhexidine

Graph 4

Mean bacterial viability ratio of samples after laser and CHX treatments. CHX: Chlorhexidine