In recent years there have been an increasing number of in vitro and in vivo studies that show positive results regarding antimicrobial photodynamic therapy (aPDT) used in dentistry. These include applications in periodontics, endodontics, and mucosal infections caused by bacteria present as biofilms. Antimicrobial photodynamic therapy is a therapy based on the combination of a non-toxic photosensitizer (PS) and appropriate wavelength visible light, which in the presence of oxygen is activated to produce reactive oxygen species (ROS). ROS induce a series of photochemical and biological events that cause irreversible damage leading to the death of microorganisms. Many light-absorbing dyes have been mentioned as potential PS for aPDT and different wavelengths have been tested. However, there is no consensus on a standard protocol yet. Thus, the goal of this review was to summarize the results of research on aPDT in dentistry using the PubMed database focusing on recent studies of the effectiveness aPDT in decreasing microorganisms and microbial biofilms, and also to describe aPDT effects, mechanisms of action and applications.

The use of violet LED was recently introduced as a new alternative technique to perform tooth bleaching, associated or not with bleaching agents. This paper shows a tooth bleaching clinical case report performed in a 26-year-old woman, using a violet LED with 10% carbamide peroxide (CP). The tooth bleaching protocol was performed in 3 sessions. Fifteen irradiations using a violet light system (BMW, MMoptics, São Carlos, SP, Brazil) were done during 30 s (on) and 60 s (off) without bleaching gel, and more 5 irradiations associated to 10% CP. Upper and lower arches were irradiated separately. The total procedure time was 30 min. Subjective and objective color assessments were performed using Vitapan Classical shade guide and VITA Easyshade spectrophotometer, respectively. Dentin sensitivity was measured using a visual analogue scale. The use of violet LED associated to a low concentration carbamide peroxide successfully promoted tooth bleaching and no side effects i.e. dentin sensitivity during and post treatment was observed.

Since low concentration bleaching agents containing N-doped TiO2 nanoparticles have been introduced as an alternative to conventional agents, it is important to verify their efficacy and the hypersensitivity effect in clinical practice. Six volunteer patients were evaluated for color change and hypersensitivity after bleaching using 35% H2O2 (one session of two 12 min applications) and 6% H2O2/N-doped TiO2 (one session of three 12 min applications) and after low level laser therapy application (LLLT) (780 nm, 40 mW, 10 J.cm−2, 10 s). Based on this case study, the nanobleaching agent provided better or similar aesthetic results than the conventional agent under high concentration, and its association with LLLT satisfactorily decreased the hypersensitivity. The 6% H2O2/N-doped TiO2 agent could be used instead of conventional in-office bleaching agents under high concentrations to fulfill the rising patient demand for aesthetics.