Comparison of the antimicrobial efficacy of calcium hydroxide and photodynamic therapy against enterococcus faecalis and candida albicans in teeth with periapical lesions; an in vivo study

Introduction: Elimination of pathological microflora of root canal systems is a major goal in endodontic treatment. This study aimed to compare the antimicrobial efficacy of calcium hydroxide as an intracanal medication and antibacterial photodynamic therapy [aPDT] against Enterococcus faecalis and Candida albicans in teeth with periapical [PA] lesions

Methods: This in vivo study was conducted on 20 patients with single-rooted mandibular premolar with previously failed endodontic treatment. This study was performed as a clinical trial [IRCTID: IRCT2016090429686N1]. After conventional chemo-mechanical root canal preparation [hand and rotary instruments and 2.5% NaOCl], microbiological samples were obtained using sterile paper points, then stored in thioglycolate solution and transferred to a microbiology laboratory. Group 1 [n = 10] specimens underwent aPDT [diode laser 808 nm + 50 mg/mL methylene blue], while creamy calcium hydroxide paste was used in group 2 for a duration of 1 week. A control sample was taken with sterile paper points and F3 Protaper rotary file. The samples were dispersed in transport medium, serially diluted, and cultured on selective mediums to determine the number of colony forming units [CFUs]. Data were analyzed by Mann-Whitney U test at 5% significance level. The significance level for all analyses was set at P < 0.05

Results: Number of CFU significantly decreased in both groups after the interventions [P < 0.001]; however, there was no significant difference in the colony count between the 2 groups

Conclusion: aPDT and calcium hydroxide therapy showed the same antimicrobial efficacy on E. faecalis and C. albicans

antibacterial effect of additional photodynamic therapy in failed endodontically treated teeth: a pilot study

Introduction: root canal therapy as a routine dental procedure has resulted in retention of millions of teeth that would otherwise be lost. Unfortunately, successful outcomes are not always achievable within initial endodontic treatments, and that necessitates further treatment. Nonsurgical retreatment is the first choice in most clinical situations. The aim of this clinical pilot study was to assess the effect of additional photodynamic therapy [PDT] on intraradicular bacterial load following retreatment of failed previously root treated teeth

Methods: thirty single-rooted/canalled endodontically treated matured teeth [in 27 healthy patients] accompanied by apical periodontitis [AP] were selected for this study. Standard protocol was followed for nonsurgical retreatment of each tooth. Microbiological samples were taken after establishment of apical patency, finished cleaning/shaping procedure, and PDT [665 nm, 1 W, 240 seconds]. All samples were cultured for 72 hours and colony-forming unit [CFU] was counted. McNemar test was used for statistical analysis of the data. The level of significance was set at 0.001

Results: routine cleaning and shaping resulted in twenty four negative [80%] out of 30 cultures. Four additional negative results were obtained after additional PDT [93.3%]. The addition of PDT to routine procedures significantly enhanced the number of bacteria-free samples [P < 0.001]

Conclusion: regarding elimination of intraradicular microbiota, additional PDT may increase the effectiveness of conventional chemomechanical preparation in previously root filled teeth accompanied by AP. Well controlled randomized clinical trials should be planned for future

Expedited removal of pyogenic granuloma by diode laser in a pediatric patient

Pyogenic granuloma [PG] is one of the inflammatory hyperplasia seen in the oral cavity. It is a reactional response to minor trauma or chronic irritation. The most common treatment of PG is surgical excision but alternative approaches such as laser excision have also been proposed especially for pediatric patients. Herein, we present a case of gingival pyogenic granuloma in a 6-year-old patient. The lesion was excised successfully with diode laser as a conservative and non-stressful method in a pediatric patient. The use of laser as modern medicine offers a new tool for treatment of oral lesions as comfortable as possible in pediatric patients, which results in less stress and fear in children

Qualitative analysis of teeth and evaluation of amalgam elements penetration into dental matrix using laser induced breakdown spectroscopy

Introduction: In this study, laser induced breakdown spectroscopy [LIBS] is used for qualitative analysis of healthy and carious teeth. The technique of laser ablation is receiving increasing attention for applications in dentistry, specifically for the treatment of teeth such as drilling of micro-holes and plaque removal. Methods: A quality-switched [Q-switched] Neodymium-Doped Yttrium Aluminium Garnet [Nd:YAG] laser operating at wavelength of 1064 nm, pulse energy of 90 m/l/pulse, repetition rate of 2Hz and pulse duration of 6 ns was used in this analysis. In the process of ablation a luminous micro-plasma is normally generated which may be exploited for on-line elemental analysis via laser induced breakdown spectroscopy technique. We propose laser induced breakdown spectroscopy as a rapid, in situ and easy method for monitoring drilling process. Results: The results of elemental analysis show the presence of some trace elements in teeth including P, Ca, Mg, Zn, K, Sr, C, Na, H, O and the permeability of some amalgam [teeth filling materials] elements including Hg, Ag, Cu and Sn into dental matrix. Conclusion: This study addresses the ability of LIBS in elemental analysis of teeth and its feasibility in acute identification of healthy and carious teeth during drilling process for future clinical applications

Posthaste outgrow of lip pyogenic granuloma after diode laser removal

Pyogenic granuloma [PG] is one of the inflammatory hyperplasia seen in the oral cavity. It is a reactional response to minor trauma or chronic irritation and also might be related to hormonal changes. Rarely, PG occurs extragingivally.The most common treatment of PG is surgical excision but alternative approaches such as laser excision have also been proposed. Herein, we present a case of lip pyogenic granuloma in a 15-year-old male whom had been under orthodontic treatment. The lesion was first excised with diode laser as a conservative method, but the lesion had immediately recurred and was excised with surgical blade as the traditional method. No recurrence or scarring was observed in 6 months follow-up. Although the use of laser as modern medicine offers a new tool for treatment of oral lesions, scalpel [blade] surgical excision still seems to be the successful treatment of choice in minimizing the recurrence of lesion especially when exacerbating factors such as hormonal imbalances exist

Application of laser in oral surgery

In this review collected from the literature on usage of laser in oral minor surgery based on a Medline search in the time period between the years: 2008 and 2013, the most current evidence on laser-assisted oral minor surgery is going to be surveyed

Effectiveness of lasers in the treatment of dentin hypersensitivity

Dentin hypersensitivity [DH] is a relatively common painful condition among dental problems. Although many studies have been performed regarding the diagnosis and treatment of DH, dental practitioners are still confused about the definite diagnosis and treatment. The use of lasers as a treatment for dentin hypersensitivity was first introduced in 1985. Laser treatment in dentin hypersensitivity is an interesting and controversial issue and many investigations have been done on its mechanism of action, advantages, and unclear points. The present literature review tries to go over the definition, diagnosis, etiology, predisposing factors, various laser types in the treatment of DH alone or in combination with topical desensitizing agents. Since a certain treatment has not yet introduced for dentin hypersensitivity, a combination of laser therapy and topical desensitizing factors, can increase the success of the treatment compared with either treatments alone

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

Clinical application of 810nm diode laser to remove gingival hyperplasic lesion

Several treatment options have been introduced for removal of gingival hyperplasic lesions, but using diode lasers have many advantages such as less bleeding, time saving, better shaping, improved healing and less complication for the patients. A 15-year-old girl with multiple fibroma-like lesions in the oral cavity, who had a medical history of tuberous sclerosis, was selected for gingivoplasty treatment with 810nm diode laser. A perfect shaping was obtained after removal of the whole lesion in one session and no recurrence was observed in 6 months. Using laser in the treatment of oral lesions leads to excellent wound healing along with excellent functional results

Clinical application of 810nm diode laser and low level laser therapy for treating an endodontic problem a case presentation

The standards of endodontics have constantly been raised in the last 25 years by practitioners' researches and their interest. Most of the scientists believe the recent developments and the use of lasers as the most exciting achievement in endodontic treatment. Nowadays, lasers are being used in endodontics to improve the prognosis of the root-filled teeth. The Implement of suitable wavelengths, together with conventional methods, can effectively sterilize the canal, dentin and periapical regions. This article describes a successful treatment of an endodontic case using 810nm diode laser and low Level Laser and sixteen months follow-up to improve healling of the edema

Conventional versus digital radiographs in detecting artificial voids in root canal filling material

Inappropriate condensation of gutta-percha or improper use of sealer can lead to voids in root canal filling material and consequent failure of the treatment. Timely detection of voids within root canal filling may prevent complications. In this study, we compared the accuracy of digital and conventional radiograph for detecting voids within root canal fillings. The root canals of 50 extracted maxillary permanent incisors were prepared and filled with gutta-percha and sealer. The teeth were then randomly divided into two groups of 25 incisors. The teeth were imaged using the paralleling technique with E-speed film and digital/digital zoomed system. The accuracy of radiographic techniques was evaluated for detecting voids by three independent observers. Presence/absence of voids was recorded and compared with the baseline data. The sensitivity, specificity, accuracy and positive and negative predictive values was recorded. The sensitivity, specificity and accuracy of conventional radiography and digital radiography were 48%, 52%, 50%, and 82.7%, 80% and 81.3%, respectively. The positive and negative predictive value of conventional radiography was 50%. Digital images showed the positive predictive value of 80.3% and negative predictive value of 83.5%. The values of positive and negative predictive were reported as 81.6% and 81.1% in digital zoomed images. Digital and digital zoomed images performed better than conventional radiographs in detecting voids, but there were no differences between the performances of both digital images

invitro study on the temperature changes of dentin, irradiated by CO2 and Er: Cr;YSGG laser

Aim of this in-vitro study was the evaluation of temperature changes due to irradiation of two different lasers used for the reduction of dentinal hypersensitivity and their effect on the pulp damage. The study was done for two dentin thicknesses. Twenty intact extracted third molars were prepared by longitudinal ground sectioning for 1 and 2 mm dentin thicknesses while a thermocouple was positioned at the inner surface of the dentin disk. Thermal evaluation was assessed by a KJT digital thermometer. During the test, the data produced by the thermometer was transferred and logged into a PC via RS232 serial port. CO2 laser [Ultra pulse, 50W, 100?sec, Spot size: 0.5 mm] and Er,Cr;YSGG laser [Free-running pulse mode,0. 25W, 140?sec, 12.50 milli-joules] irradiations were randomly performed upon the dentin surfaces. The collected data was analyzed by two-way ANOVA test. The mean temperature rise in 1mm dentinal thickness was 8.57°C which was significantly higher than 3.63°C in 2mm dentin thickness [P<0.001] and higher than the threshold temperature for pulp damage; however, no significant difference was noted between the two lasers [P=0.355]. After removing the CO2 laser, the temperature decreased to the initial level faster than the time needed for Er,Cr;YSGG laser [44.47°C versus 62.82°C][P<0.001]. In other words, in both lasers the temperature decrease in 2mm dentinal disc was faster than 1mm dentinal disc. The temperature rise due to both lasers for 1mm of dentinal thickness was in excess of safe limit for the tissue and it would probably result in pulpal damage. In the case of 2mm dentinal thickness, the temperature rise was not higher than the safe limit and it would not damage the pulp in clinical conditions

effect of Er,Cr:YSGG laser irradiation on the apical leakage of retrograde cavity

Controversial results have been reported when organic acids, ultrasonic instruments and laser techniques were used to remove smear layer in endodontic treatments. The aim of this study was to evaluate the effect of removing debris and smear layer by Er,Cr:YSGG laser irradiation on the apical leakage of retrograde cavities. In this ex vivo study, 24 extracted mandibular single-rooted teeth were selected and instrumented up to K-file size #35. Approximately 3 mm of root apices were dissected perpendicular to the root's long axis. Retrograde cavities with 3 mm depth were prepared and the teeth were randomly assigned to two groups. In one group, the retrograde cavities were filled with amalgam and in the other group, the dentinal surface of the retrograde cavities were lased with Er,Cr:YSGG laser [2W, 15 seconds, G4 tip]. The cavities were filled with amalgam; all tooth surfaces except for dissected outsides were covered with blue wax. Then the teeth were immersed in 2% methylene blue dye for 48 hours. The amount of dye penetration into sagittal sections was measured by stereomicroscope at _20 magnification by two independent observers who were blinded to the experiment. Data were statistically analyzed using student t-test. This study demonstrated that dye penetration was 0.8 mm [ +/- 0.53] in the lased and 0.97 mm [ +/- 0.54] in the non-lased group. It showed that, Er,Cr:YSGG laser can remove the debris and smear layer and consequently reduces the amount of dye penetration, although, the difference between the two groups was not statistically significant. This study showed that dye penetration was less in lased group because of the better seal of the dissected surface due to the better removal of the debris and smear layer by laser; further investigations are recommended in this field