We Have Numbers Of Free Samples

Periowave

Periowave is a photodynamic disinfection system that utilizes nontoxic dye (Photosensitizer) in combination with a low-intensity lasers enabling singlet oxygen molecules to destroy bacteria. It inactivates the bacteria and toxins left behind after scaling and root planning by using a photo disinfection reaction. A small quantity of blue-colored photosensitizer solution is topically applied to the treatment site where it attaches to microbes and toxins associated with gingival or periodontal disease followed by a low-intensity laser which is directed on the area treated with the drug resulting in phototoxic reactions destroying bacteria beneath the gingival line. Each treatment site requires only 60 seconds of laser activation, making it a quick and painless procedure.

Antimicrobial Photodynamic Therapy (APDT):

APDT involves three components:

• Light,
• A photosensitizer
• Oxygen

A photosensitizer is topically administered to the patient at an infection site. Upon irradiation with light of a specific wavelength, the photosensitizer undergoes a transition from a low-energy ground state to an excited singlet state and the transfer of energy from the light activated photosensitizer to available molecular oxygen produces toxic reactive oxygen species, such as singlet oxygen and free radicals.

These reactive chemical species mediate the destruction of microbes primarily via lipid peroxidation and bacterial membrane damage. APDT has been proven efficacious in the treatment of bacterial, fungal, parasitic, and viral infections. One major advantage of APDT is that due to this non-specific bactericidal mechanism, it is not subject to the issues of resistance due to use of antibiotics. APDT is equally effective against antibiotic-resistant and antibiotic-susceptible bacteria, and repeated photosensitization has not induced the selection of resistant strains.

The absence of genotoxic and mutagenic effects of APDT is an important factor for long-term safety during treatment. APDT is a localized topical treatment that can be administered in areas such as the oral cavity. It represents a novel therapeutic approach in the management of oral biofilms. Its applications in dentistry are expanding rapidly: in the treatment of bacterial and fungal infection therapies, periodontal diseases and endodontic therapy.

The Photosensitizer:

The selective efficacy of the technique against bacteria appears to be related to the charge of the sensitizer. Phenothiazinium dyes like methylene blue (MB) are positively charged (cationic) sensitizers.

The cell walls of gram-negative microorganisms have higher lipid content than gram-positive cells and bear a negative charge, which has a strong affinity for positively, charged photosensitizers as opposed to mammalian cells, which do not. Electron microscopy revealed complete eradication of bacteria in uniform biofilms of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, or Prevotella intermedia, prepared on different implant surfaces treated with phenothiazinium dye and irradiated with a diode laser APDT requires a low-power source of light that activates the photosensitizer at a specific wavelength.

For example, methylene blue (a well-tolerated cationic phenothiazinium dye used for over 100 years in other medical applications) is an efficient APDT photosensitizer with well-defined absorption peak at 670 nm (dark red). Human tissue transmits red light (between 630 and 700 nm) efficiently with minimal absorption, and the activation wavelength of the methylene blue photosensitizer results in more effective light penetration, permitting access to deeper infection sites. The total required light dose, dose rates, and resulting degree of microbial destruction varies with local tissue pigmentation, degree of uptake of the sensitizer, type and frequency of each microorganism, age of the biofilm containing the microorganisms, surrounding blood and plasma exudates and the nature of the surrounding tissue. ⁽⁵⁵⁾

The sensitizers used for medical purposes belong to the following basic structure:

1. Tricyclic dyes with different Meso Acridine orange, Proflavine, riboflavin, Methylene blue, Fluorescein and Erythrosine.
2. E.g.: Porphyrins and derivatives, Chlorophyll, Phylloerythrin and Phthalocyanines.
3. E.g.: Psoralen and its Methoxyderivatives, Xanthotoxin and Bergaptene^{. (56)}

Figure: Photodynamic Therapy

Mechanism of Action:

The bactericidal effect of photodynamic therapy is explained by two potentials, but different, mechanisms namely the DNA damage and the damage caused to the cytoplasmic membrane of the bacteria by cytotoxic species generated by antimicrobial photodynamic therapy. After irradiation with light of a specific wavelength (lasers), the photosensitizer at ground state is activated to a highly energized triplet state. The longer lifetime of the triplet state enables the interaction excited photo sensitizer with the surrounding molecules resulting in the generation of cytotoxic species. There are two different pathways (type I and II) to react with biomolecules.

Type I reactions involve hydrogen electron-transfer reactions between the excited state of the photosensitizer and an organic substrate molecule of the cells, which produces free radicals and radical ions. These free-radical species are highly reactive and interact with endogenous molecular of highly reactive oxygen species such as superoxide, hydroxyl radicals and hydrogen peroxide, which are harmful to cell membrane integrity and result in irreparable biological damage.

In the type II reaction, the reacts with oxygen to produce a highly reactive state of oxygen, known as singlet oxygen with a large number of biological substrates due to its high chemical reactivity, inducing oxidative damage and ultimately lethal effects upon the bacterial cell by damaging the cell membrane and cell wall. Singlet oxygen has a short lifetime in biological systems (<0.04 μs) and a very short radius of action (0.02 μm) that causes limited migration of singlet oxygen, leading to a localized response and making it ideal for application at localized sites without affecting distant molecules, cells or organs. The process of antimicrobial photodynamic therapy is generally mediated by a type II reaction major pathway in microbial cell damage. ^{(56, 57)}

Figure: Mechanism of Photodynamic Therapy

Photodynamic Therapy and Periodontitis:

Biofilm in oral cavity causes two of the most common diseases, dental caries and periodontal diseases. An effective approach of periodontal therapy is to change the local environment to suppress the growth of periodontal pathogens. Using antimicrobial agents to treat periodontitis without disruption of the biofilms ultimately results in treatment failures. It is difficult to maintain therapeutic concentrations at the target sites and target organisms can develop resistance to drugs. This resistance is minimized by using PDT. Polysaccharides present in extracellular matrix of oral biofilm are highly sensitive to singlet oxygen and susceptible to photo damage. Breaking the biofilm may inhibit plasmid exchange involved in transfer of antibiotic resistance and disrupt colonization Photodynamic antimicrobial chemotherapy could be an ideal complement to conventional scaling and root planning.

During inflammation there is venous stagnation and reduced oxygen consumption by tissues. This decrease in oxygen level and change in pH enhances the growth of anaerobic species. PDT improves tissue blood flow in the microcirculatory system and reduces venous congestion in gingival tissues. Furthermore, PDT increases oxygenation of gingival tissues by 21–47 per cent which in turn decreases the time and speed of oxygen delivery and utilization, thus normalizing oxygen metabolism in periodontal tissues. The pathogenesis of periodontal diseases is explained on the basis of the virulence factors possessed by the periodontopathogens that cause activation of macrophages, production of interleukin-1, release of prostaglandin E2, which are potent stimulators of bone resorption. Endotoxin on root surface inhibits fiber reattachment on cementum.

PDT causes the inactivation of the various virulence factors secreted by microorganisms.  Upon interpretation of the data from various controlled clinical studies, the adjunctive use of PDT to scaling and root planning in the treatment of patients with chronic periodontitis, aggressive periodontitis and periimplantitis, resulted in greater clinical attachment level gains, reduction in bleeding on probing and probing pocket depths.

Effects of (PACT) Photodynamic Antimicrobial Chemotherapy On Oral Biofilms:

The use of PDT in furcation involvement in induced periodontitis shows some advantages over the use of conventional antimicrobials, such as the reduced need for flap procedures and shorter treatment time; as local therapy, with lack of micro flora disturbance in other sites of the oral cavity. PDT is also beneficial during the maintenance of periodontal therapy because it may act on the biofilm and eliminate the need for the removal of additional root substance by mechanical retreatment. Thus, the patient may experience less dentinal hypersensitivity. This therapy also serves as an adjunct to mechanical therapy in sites with difficult access. ⁽⁵⁸⁾

Effect of APDT On Peri-Implantitis:

Peri-implantitis seems to occur in 5-10% of all implant cases. In this way, photodynamic therapy can be used successfully to decontaminate the implant surface. Laser PDT can be used in implantology to promote osseointegration and to prevent peri-implantitis. Studies have shown that laser photo biomodulation can be successfully used to improve bone quality around dental implants, allowing early wearing of prostheses. The results of a study showed significant differences on the concentration of calcium hydroxyapatite on irradiated and control specimens and concluded that infrared laser photo biomodulation does improve bone healing. ⁽⁵⁸⁾

Antimicrobial PDT seems to be a unique and interesting therapeutic approach towards the treatment of periodontitis. The results of a number of in vitro studies clearly demonstrate the effective and efficient bactericidal effect of antimicrobial PDT. However, sufficient clinical and microbiological data that support the superior effects of the adjunctive use of PDT have not been demonstrated in vivo or clinically in either periodontal or peri-implant therapies. The discrepancy in the results obtained from previous clinical studies may be a result of the differences in treatment conditions and parameters. Therefore, further in vivo and clinical studies are necessary to determine the optimal conditions of this novel therapy. Furthermore, further randomized long-term clinical studies and meta-analyses are necessary to demonstrate the beneficial effects of antimicrobial photochemical therapy and their real advantages in comparison with conventional methods. ⁽⁵⁹⁾

Photodynamic therapy may contribute to the overall success of conventional periodontal therapy showing significant improvement of periodontal condition. On the other hand, microbiological composition of the treated sites did not significantly improve from baseline composition. Long-term clinical and more complex microbiological studies are needed to elucidate the mechanism of action of this novel therapeutic approach. ⁽⁶⁰⁾

Periodontal Waterlase:

Target Applications of Periodontal Waterlase are restorative and multi-disciplinary dentistry procedures, cosmetic procedures, Oral surgery, Endo disinfection, Implants and Periodontal treatment. Kelbauskiene S et al., carried a study and concluded that the Waterlase MD laser utilizes Er, Cr: YSGG minimally invasive surgical periodontal laser therapy that results in significant improvements in bleeding on probing, probing depth, and appears to be advantageous when compared to scaling and root planning alone, due to more efficient attachment level restoration. ⁽⁵⁴⁾

Erbium-Chromium doped: Yttrium-Selenium – Gallium-Garnet (Er, Cr: YSGG) laser is commercially available as Waterlase. It uses a patented combination of laser energy and water by a process called Hydro photonics, to perform a wide range of dental procedures. The Hydrokinetic process is the removal of tissues with YSGG laser-energized water droplets. Hydrokinetic energy is produced by combining a spray of atomized water with laser energy. The resulting Hydrokinetic energy gently and precisely removes a wide range of human tissue including tooth enamel and soft tissue with no heat and no pain in most cases. Laser-powered hydrokinetic system (LPHKS) uses an Er, Cr: YSGG crystal with a photon emission wavelength of 2.78 micrometers (Hadley et al, 2000). The absorption coefficient for water is 0.00029 for argon laser, 0.020 for diode laser, 0.61 for Nd: YAG laser, 12,000 for Er: YAG laser and 860 for CO2 laser. The absorption coefficient of water of the Er: YAG laser is theoretically 10, 000 which is 15,000-20,000 times higher than that of the CO2 and Nd: YAG lasers, respectively.

The laser hand piece resembles a high-speed hand piece but with fiber optic tips instead of bur, which directs the laser energy at a focal point approximately 1 to 2 mm from tissue surface. Weighing 88 pounds, waterlase has dimensions of 12.5×26×32 inch. It requires about 80 pounds per square inch of air pressure provided by an external air source. The water supply is located in an attached bottle that is easily removed for water replacement. The proposed mechanism of Laser-powered hydrokinetic system (LPHKS) is that the Er, Cr: YSGG pulsed laser source delivers photons into an air-water spray matrix with resultant micro explosive forces on water droplets. The laser energy couples the hydroxyl radical in the apatite crystal and the water that is bound to the crystalline structures of the tooth. The vaporization of the water within the mineral substrate causes a maximum volume expansion that causes the surrounding material to explode away. The LPHKS with its accompanying air water spray has been shown to cut enamel, dentin, cementum and bone efficiently and cleanly without deleterious thermal effects on dental pulp. Scanning electron microscopy has shown that LPHKS makes clean cut through enamel and dentin without creating smear layer.

A mechanism of action of biological tissue ablation with waterlase has been proposed, based on the optical properties of its emission wavelength and morphological features of the surface ablated by the waterlase. During the waterlase irradiation, the waterlase energy is absorbed selectively ablated by the waterlase. During the waterlase irradiation, the waterlase energy is absorbed selectively by water molecules and hydrous organic components by water molecules and hydrous organic components of biological tissues, causing evaporation of water and organic components and resulting in thermal effects due to the heat generated by this process (photothermal evaporation).

Moreover, in hard tissue procedures, the water vapor production induces an increase of internal pressure within the tissue, resulting in explosive expansion called ‘micro explosion’. These dynamic effects cause mechanical tissue collapse, resulting in ‘thermomechanical’ or ‘photomechanical’ ablation. This phenomenon has also been referred to as ‘water mediated explosive ablation’. For hard tissue procedures, working on teeth the work is actually done by a laser energized through a “hydrokinetic” process. It has been indicated by various studies that Er, Cr: YSGG laser is a suitable procedure for use on bone without any evidence of charring or melting.

When cutting hard tissue, no physical contact is made with the tissue. That is, the laser energy is transferred to the water, which is then transferred to the tooth vaporizing the tissue. For hard tissue applications spray is part of tissue removal process as well as hydration, cooling and keeping the tissue clean. Soft tissue procedures are performed using a different mode of operation where direct Er, Cr: YSGG laser energy is applied to incise, excise or ablate these tissues. For laser application to the soft tissues, adequate anesthesia of that area is required. In soft tissue procedures the water is applied for hydration, cooling or to keep tissue clean.

A flexible fiber-optic device delivers the waterlase laser energy. For the soft tissue procedures, the laser itself does the cutting with the water stream acting as a coolant. A visible light emitted from hand piece distal end pinpoints the area of treatment. In both hard and soft tissue applications the power output, the pulse energy, repetition rate and air and water flow rates are adjustable to specific user requirements.

With respect to healing after Er: YSGG scaling, no histologic studies have been reported after periodontal treatment using the Er: YAG laser, min thermal changes have been reported after Er: YSGG irradiation on both hard and soft tissue.

Therefore, further studies are necessary to clarify the histologic attachment of periodontal tissues to the irradiated root surface in vivo. The Waterlase laser was first cleared by the Food & Drug Administration (FDA) to cut tooth structure in 1998. ⁽⁶¹⁾

Figure: Waterlase

Laser Assisted Peri-Implantitis Procedure:

Various treatment protocols for peri-implantitis are described in the literature. However, there is no compelling evidence to suggest a superior surgical procedure for more advanced cases, and more evidence is needed to fully evaluate alternative light activated disinfection (LAD). Several recent studies have found laser therapy a promising treatment of periodontal disease and now peri-implantitis. Specifically, pulsed neodymium: yttrium aluminum garnet laser irradiation (Nd: YAG) has been investigated and its efficacy determined for achieving bacterial ablation without damaging the surface properties of titanium implants.

Treating peri-implantitis are its ability to penetrate the soft tissue to achieve an effective kill of bacteria, and its ability to promote effective hemostatis. Whereas some lasers and their wavelengths (e.g., mid-infrared) only achieve surface effects on tissues, the Nd:YAG laser penetrates several millimeter  into soft tissue and dentin. This is a significantly favorable and distinguishing characteristic of the Nd:YAG laser, since the great depth of penetration of the free running, pulsed laser energy allows for a greater kill rate of black pigmented bacteria and the ability of the laser energy to affect deeper blood vessels, creating excellent hemostasis.

The CO2 and erbium lasers are not as well suited for the laser procedure. Both laser types have wavelengths that are highly absorbed by water and consequently very shallow penetration depths in tissues. Thus, they cannot access pathogens or affect hemostasis below the surface.

With the Nd: YAG laser, the amount of collateral thermal damage is directly proportional to the duration of irradiation. For a short pulse duration of 100 μsec, the zone of thermal damage is slight (e.g., a few 10s of microns[μ]), compared to a “long” pulse of 650 μsec, which creates a narrow zone of coagulation around the irradiation site affecting hemostasis. Significant thermal damage can result with even longer irradiation times, such as from the continuous irradiation mode of the diode laser. Therefore, the combined characteristics of the variable pulsed emission mode of the PerioLase Nd:YAG laser and its near-IR wavelength of 1064nm, affecting deep tissue penetration, make it specifically suited for a laser assisted peri-implantitis procedure (LAPIP).

The Nd:YAG laser (PerioLase MVP-7) is at the heart of the Laser-Assisted Peri-Implantitis Procedure (LAPIP) that is based on the successful LANAP (Laser-Assisted New Attachment Protocol) therapy. An emerging experimental technique for treating PI is the laser-assisted PI protocol. ⁽⁶⁷⁾

The LANAP therapy is an FDA-approved protocol that provides cementum-mediated new periodontal ligament attachment to root surfaces in the absence of long junctional epithelium. It treats the periodontal pocket walls to remove diseased epithelium, then seals them with a laser-generated blood clot. The therapy results in greater probing depth reduction and clinical probing attachment level gains, as well as induces periodontal regeneration.  The LAPIP technique is basically an implant-specific modification to the LANAP procedure. Both utilize an ablation step to remove inflamed sulcular tissue and decontaminate the root/implant surface, followed by a scaling. A laser induced hemostasis step further decontaminates the tissue and causes the blood to clot, creating a closed system. This seals the area, preventing the down growth of the gingival epithelium and allowing the area to heal from the base of the defect coronally. ⁽⁶⁶⁾

Figure: LAPIP Protocol Steps

[Download not found]

Download