Evaluation of the effect of low level laser therapy toothbrush in treatment of dentin hypersensitivity

Introduction: Dentin hypersensitivity is one of the most common complications that affect patients after periodontal therapy. Recently low level laser therapy has been introduced as a new treatment modality and has produced beneficial results. The purpose of this study is to evaluate the effect of low level laser therapy toothbrushes in reduction of dentin hypersensitivity. Methods: In this pilot interventional controlled clinical trial, 40 patients suffering from dentin hypersensitivity were selected using simple r and omization. Half of the patients were given laser toothbrushes and the other half was given non-laser sensodyne toothbrushes. Primary dentin hypersensitivity was recorded by visual analogue scale [VAS] score and ice spray. Then dentin hypersensitivity was measured right after the treatment as well az in the intervals of 1 month and 2 months after initiation of the study. Data were compared using Statistical Package for the Social Sciences [SPSS] software and Analysis of variance [ANOVA] paired T test. Results: The results of this study showed that there was a significant difference in each of the two kinds of tooth brushes separately for all time intervals [P < 0.001]. Also the effect of the type of toothbrush was investigated using before treatment VAS with covariance analyses. P values for immediately, 1 month and 2 months after treatment were calculated to be 0.078, 0.02, 0.01 respectfully. Also the effect of the toothbrush type was significant in the manner that laser toothbrushes reduce dentin hypersensitivity more than ordinary toothbrushes [P< 0.05]. Conclusion: Both sensodyne and laser tooth brushes improve dentin hypersensitivity, although the laser toothbrush led to better results in short

Shear bond strength of the repair composite resin to zirconia ceramic by different surface treatments

The purpose of this study is the evaluation of the amount of surface roughness [Ra] of Zirconia Ceramic following different surface treatments as well as the assessment of its shear bond strength to composite resin. 40 sintered zirconia ceramic block samples were randomly divided in 4 groups of 10 and underwent the following surface treatments: a] Control group without treatment b] Air abrasion with Al2O3 particles [50um] c] Er:YAG laser with 2W power for 10s d] Nd:YAG laser with 1.5W power for 2min Then the mean surface roughness [Ra] was evaluated by profilometer. In the next step, Alloy primer was used on a section of 9mm[2]on the samples following the manufacturer's instructions. After that Clearfil AP-X composite resin in cylinder shape with an internal diameter and height of 3mm were cured on the sections mentioned. At the end, all samples were tested to assess the shear bond strength by the Universal Testing Machine at a speed of 0.5mm/min until fracture occurred. The mean shear bond strengths were calculated and statistically analyzed by One Way ANOVA. ANOVA analysis showed that roughness [Ra] was significantly different between the groups [P

Effect of surface treatment with carbon dioxide [CO[2]] laser on bond strength between cement resin and zirconia

Since it is not possible to form an adequate micromechanical bond between resin cement and zirconia ceramics using common surface treatment techniques, laser pretreatment has been suggested for zirconia ceramic surfaces. The aim of this study was to evaluate the effect of Carbon Dioxide [CO[2]] Laser treatment on shear bond strength [SBS] of resin cement to zirconia ceramic. In this in vitro study thirty discs of zirconia with a diameter of 6 mm and a thickness of 2 mm were randomly divided into two groups of 15. In the test group the zirconia disc surfaces were irradiated by CO[2] laser with an output power of 3 W and energy density of 265.39 j/cm[2]. Composite resin discs were fabricated by plastic molds, measuring 3 mm in diameter and 2 mm in thickness and were cemented on zirconia disk surfaces with Panavia F2.0 resin cement [Kuraray Co. Ltd, Osaka, Japan]. Shear bond strength was measured by a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture type was assessed under a stereomicroscope at ×40. Surface morphologies of two specimens of the test group were evaluated under SEM before and after laser pretreatment. Data was analyzed by paired t-test [p value < 0.05]. The mean SBS values of the laser and control groups were 12.12 +/- 3.02 and 5.97 +/- 1.14 Mpa, respectively. Surface treatment with CO[2] laser significantly increased SBS between resin cement and zirconia ceramic [p value = 0.001]. Under the limitations of this study, surface treatment with CO[2] laser increased the SBS between resin cement and the zirconia ceramic

Disinfection of contaminated canals by different laser wavelengths, while performing root canal therapy

Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the aforementioned articles indicate that this laser is effective in combination with a rinsing solution such as sodium hypochlorite. Results from studies including several types of the different Er:YAG, Ho:YAG, Nd:YAG, Er,Cr:YSGG lasers in disinfecting canals showed that all wavelengths used in disinfection for different thicknesses of dentin were efficacious without damaging thermal effect. Considering that use of different lasers in canals can be accompanied with temperature increase which can sometimes lead to damages to teeth and surrounding tissues, thus the use of photochemical phenomenon for elimination of microorganisms have attracted attention of many researchers. Studies in this field imply the efficacy of this method in reducing canal bacterial count and recommend its use as an adjunctive after biomechanical preparation of canals. Results from performed studies show removal of intra canal debris and smear layer by different lasers and particularly the Erbium laser family. Furthermore various laser wavelengths, particularly of Diode and Nd:YAG lasers can be effective in reducing intra canal microbial count. Maximum effect is obtained when laser light is used in canals in combination with sodium hypochlorite irrigating substance in appropriate concentration. Therefore use of laser energy can improve success rate of root canal treatments

Application of low level lasers in dentistry [endodontic]

Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surface unit [i.e cm[2]]. Density lower than 670mW/cm[2], can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers [therapeutic] used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented

Evaluation of accuracy of DIAGNOdent in diagnosis of primary and secondary caries in comparison to conventional methods

Today the prevalence of teeth decays has considerably decreased. Related organizations and institutions mention several reasons for it such as improvement of decay diagnostic equipment and tools which are even capable of detecting caries in their initial stages. This resulted in reduction of costs for patients and remarkable increase in teeth life span. There are many methods for decay diagnostic, like: visual and radiographic methods, devices with fluorescence such as Quantitative light-induced fluorescence [QLF], Vista proof, Laser fluorescence [LF or DIAGNOdent], Fluorescence Camera [FC] and Digital radiography. Although DIAGNOdent is considered a valuable device for decay diagnostic, there are concerns regarding its efficacy and accuracy. Considering the sensitivity of decay diagnosis and the exorbitant annual expenses supported by government and people for caries treatment, finding the best method for early caries detection is of the most importance. Numerous studies were performed to compare different diagnostic methods with conflicting results. The objective of this study is a comparative review of the efficiency of DIAGNOdent in comparison to visual methods and radiographic methods in the diagnostic of teeth occlusal surfaces. Search of PubMed, Google Scholar electronic resources was performed in order to find clinical trials in English in the period between 1998 and 2013. Full texts of only 35 articles were available. Considering the sensitivity and specificity reported in the different studies, it seems that DIAGNOdent is an appropriate modality for caries detection as a complementary method beside other methods and its use alone to obtain treatment plan is not enough.

Diode laser application in soft tissue oral surgery

Diode laser with wavelengths ranging from 810 to 980 nm in a continuous or pulsed mode was used as a possible instrument for soft tissue surgery in the oral cavity. Diode laser is one of laser systems in which photons are produced by electric current with wavelengths of 810, 940 and 980nm. The application of diode laser in soft tissue oral surgery has been evaluated from a safety point of view, for facial pigmentation and vascular lesions and in oral surgery excision; for example frenectomy, epulis fissuratum and fibroma. The advantages of laser application are that it provides relatively bloodless surgical and post surgical courses with minimal swelling and scarring. We used diode laser for excisional biopsy of pyogenic granuloma and gingival pigmentation. The diode laser can be used as a modality for oral soft tissue surgery.