Application of Photodynamic Therapy and Diode Laser for Endodontic Therapy of Young Permanent Teeth
Condition: Teeth, Endodontically-Treated
MeSH terms: Tooth, Nonvital
Study type: Interventional
Phase: Phase 2

Summary: 
      The pulp necrosis of permanent immature teeth implies the interruption of the root formation
      and apical closure. Diode lasers have been used in many areas of dentistry, with tendency of
      good results in canal and dentine disinfection. The bactericidal effect of high-power lasers
      is based on dose dependent heat generation. Its antimicrobial effectiveness against diverse
      microorganisms has already been demonstrated. Photodynamic therapy (PDT) is a two-step
      therapeutic approach starting with the application of a photosensitizing agent and followed
      by irradiation with light energy that is spectrally matched to activate the drug. The balance
      between disinfection and the creation of an intracanal microenvironment conducive for the
      proliferation of stem cells requires further investigation. Aims of study are to compare the
      time required to obtain the clinical healing and the disappearance of clinical symptoms, and
      absence of periapical radiolucency, by using PDT and diode laser, with standard disinfection
      alone; to assess specificity of microbial load in permanent immature teeth, and root canal
      disinfection ability of PDT and diode laser, in compare with standard disinfection alone.
    

Detailed description: 
      Background and Significance The pulp necrosis of permanent immature teeth implies the
      interruption of the root formation and apical closure. It is then necessary to implement a
      therapy to induce a calcified barrier at the apical end of the root. The endodontic
      management of permanent immature teeth is fraught with challenges. Although treatment
      modalities for vital pulp therapy in these teeth provide long-term favorable outcome, the
      outcomes from the treatment of pulp necrosis and apical periodontitis are significantly less
      predictable. Key role of microorganisms in the causing and development of pulpal and
      periapical diseases have been demonstrated, and their presence in the canal at the time of
      definitive filling has negative effect on success of the therapy. However, the specificity of
      microbial load of immature permanent teeth is not completely investigated, nor the influence
      of the disinfection protocols on treatment success.

      Available procedures rely heavily on root canal chemical disinfection of the root canal
      system, with minimal mechanical instrumentation. Sodium hypochlorite (NaOCl) in different
      concentrations is the most accepted solution for disinfection of root canal in endodontic.
      Despite common usage, impossibility of NaOCl to completely disinfect root canal has been
      noticed. Traditionally, irrigants and medicaments have been chosen for their maximum
      antimicrobial effect without consideration for their effects on stem cells and the dentinal
      microenvironment. The balance between disinfection and the creation of an intracanal
      microenvironment conducive for the proliferation of stem cells requires further
      investigation. This requires the interpretation of preclinical studies, and this level of
      evidence should be increased by randomized controlled clinical studies.

      Diode lasers have been used in many areas of dentistry, with tendency of good results in
      canal and dentine disinfection. The bactericidal effect of high-power lasers is based on dose
      dependent heat generation. Its antimicrobial effectiveness against diverse microorganisms has
      already been demonstrated.

      Photodynamic therapy (PDT) is a two-step therapeutic approach starting with the application
      of a photosensitizing agent and followed by irradiation with light energy that is spectrally
      matched to activate the drug. Because its high antibacterial potential, usage of photodynamic
      therapy as advance to standard protocol in root canal disinfection have been suggested.
      Studies showed positive effect of photodynamic therapy in the reduction of microbial load in
      root canal treatment. When a photoactive compound is applied in the root canal system, it is
      taken up by residual bacteria in the main canals, isthmuses, lateral canals and dentinal
      tubules. It is also possible that this compound may escape into the periapical tissues.
      During PDT, light will excite the drug in bacteria within the root canal, but could also
      potentially affect the apical stem cells that have taken up the drug. Therefore, it is
      important to determine the therapeutic window whereby host cells are left intact.

      Several studies showed wide-ranging spectra of desirable effects of low level power laser
      (LLLT) on biological tissue. It has been reported to increase cell functional activity,
      induce cell proliferation, lowers inflammation, releasing of endorphins, thus having
      analgetic effect. Furthermore, it has been shown that irradiation with a LLLT following
      photosensitization with phenothiazine chloride had no negative effect on the growth and
      differentiation of human osteoblastic cells, and did not counteract the biostimulatory effect
      induced by LLLT. There were no statistically significant differences in the growth and
      differentiation behavior between the two study groups. Further investigations of PDT on
      dental stem cells are needed to determine possible biostimulative effect on proliferation and
      differentiation, and thereby contribute to root development of non-vital permanent immature
      teeth. Prolonged treatment of young permanent teeth increases possibility of treatment
      failure. Involvement of a method that could help healing process is desirable.
    

Intervention name(s): Photodinamic therapy; Diode laser; 0.5% Sodium hypochlorite
Intervention type(s): Device; Device; Drug
Intervention description(s): Dentin sealant (HELBO® Endo Seal, Bredent, Senden, Germany) will be applied over the crown area and light cured. The root canals will be filled with the phenothiazine chloride (HELBO® Endo Blue, Bredent, Senden, Germany), agitated with a size 15K-file and left in the canal for 2 min. After this time, the root canals will be rinsed with distilled water to remove the excess of the photosensitizer, dried with paper points. The disposable 450 µm fiberoptic tip (3D HELBO® Endo Probe, Bredent, Senden, Germany) will be placed in the apical portion of the root canal at the point where resistance to the fiber will be felt, and root canal will be irradiated with HELBO® TheraLite Laser (λ = 660 nm, power = 100 mW) for 60 s (total energy, 6 J) in a continuous wave mode.; High-power diode laser therapy will be applied by using Epic diode laser (Biolase® Technology, Inc., San Clemente, CA, USA) with settings determined in laboratory researches (λ = 940 nm, maximal power 10W).; Chemomechanical preparation will be completed by hand instruments, with minimal instrumentation, and usage of sodium hypochlorite with minimal bactericidal concentration (0.5%, pH 12), on room temperature (21 degrees Celsius).
Other intervention name(s): PDT; High-power diode laser; 0.5% NaOCl
Intervention MeSH terms: Sodium Hypochlorite; Eusol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: photodynamic therapy; diode laser; immature permanent teeth; endodontic therapy