Destruction of bacterials, periimplantitis, infections, root channel infections – Photo Dynamic Therapy

Inndication Destruction of bacterials
Joule cm2 20
Frequency cw
Treeatments week 1
Device
Additional Apply Tolonium chloride and irradiate the cavity/root channel directly with the laser using a special dental applicator, fiber optic.

For disinfection, the laser is used in combination with special drugs, for the so called Photo Dynamic Therapy (PDT) or in this case Photo Dynamic Disinfection (PDD).

The PDT became available for use in both caries and infections of the soft tissue, endodontics.


Principle of function:

  1. The photosensitiser molecules attach to the membrane of the bacteria.
  2. Irradiation with light at a specific wavelength (670-690 nm) matched to the peak absorption of the photosensitiser leads to the production of singlet oxygen, which causes the bacterial cell wall to rupture, killing the bacteria.

Laboratory studies have shown that an important aspect of this system is that the two components when used independently of one another produce no effect on bacteria or on normal tissue. It is only the combination of photosensitiser and light which produces the effect on the bacteria.

How to perform the PDT/PDD

The PDT is fast, secure and easy to perform:

  1. Connect the tip of the laser probe to a the thin optical fiber, this can be a reusable or disposable hand piece.
  2. After completion of canal preparation, the canal is inoculated with the photosensitiser solution which is left in situ for a fixed period of time (60 seconds). Apply a 12.7mg/l solution of the tolonium chloride (pharmaceutical grade of the vital stain, Toluidene blue O) to the prepared tooth.
  3. Irradiate with the laser in the root canal for 120 seconds.

Aftercare: Place a non-setting calcium hydroxide paste (e.g. UltraCal) into the canal, cotton wool pledget (Roeko, Germany) in the pulp chamber and dress the tooth with IRM (Dentsply, DeTrey) in the case of posterior teeth or Chemfil Superior (Dentsply, DeTrey) in the case of anterior teeth.

This PDT system has been evaluated in the laboratory and destruction rate of bacterial is in the order of 109, achieved under conditions comparable to those found clinically

The following bacterials can be destroyed:

  • Streptococcus mutans
  • Total streptococcus
  • Streptococcus sobrinus
  • Streptococcus intermedius
  • Actinomyces
  • Lactobacillus
  • Prevotella intermedia
  • Peptostreptococcus micros
  • Fusobacterium nucleatum
  • Enterococcus faecalis