One of the most popular causes for implant infection is dental plaque bacteria. Previous studies have shown the bactericidal effect of CO2 laser irradiation on bacteria associated with soft tissue surrounding the implant materials. No published studies have examined the effect of irradiation by CO2 laser on Streptococcus oralis and Staphylococcus aureus.The aim of this study was to evaluate the bactericidal effect of CO2 laser on bacteria that are causing dental implant infections. This study was carried out on two isolates of bacterial species out of 25 samples, isolated from patients having soft tissue infections around the dental implant. These two pure isolates including Streptococcus oralis and Staphylococcus aureus were identified by microscopic examination, culture characteristics ,biochemical tests and API system. Bacterial suspension (10-6 CFU/ml) was irradiated with 10600 nm CO2 laser,CW mode emission using different power densities 500 -3000W/cm2 (500 W/cm2 increment)with different exposure times 10-60s (10 sec.increment for isolate of Streptococcus oralis) and 5-30s (5 sec. increment for isolate of Staphylococcus aureus).After the irradiation, 100μl of bacterial suspension was spread over agar plates and incubated at 37 ºC for 24-48 hrs. under aerobic and anaerobic conditions according to the nature growth of bacteria. Colony forming units (CFUs) were counted and compared with control group then the bactericidal effect of CO2 laser was assessed in relation to the colony forming units of control group.In this study the maximum bactericidal effect of CO2 laser on S.oralis was 100% at 2500W/cm2 with exposure times 50 and 60s, whereas the CO2 laser eliminated 100% of S.aureus at 3000W/cm2 at 25 and 30 s exposure time.The results indicate that irradiation by CO2 laser CW mode emission may be useful in reducing bacterial colony forming units at low (such as 1000 W/cm2) and high power density. Also the results of this study reveal that complete or nearly complete reduction in the bacterial counts may be achieved.
Dental caries (tooth decay) is one of the most prevalent infectious disease and although of multifactorial origin, Streptococcus mutans is considered the principal pathogen in its development (i.e. bacterial processes damage hard tooth structure (enamel, dentine and cementum), producing dental cavities (holes in the teeth). The bactericidal properties of the Nd:YAG laser has been researched analyzing its use in caries prevention and bacterial reduction. One hundred twenty five samples were collected from carious teeth and isolated bacteria were diagnosed using microscopic examination, culture, biochemical tests, and Api 20 strep system. The results of this study showed that a noticeable decrease in the viability of Streptococcus mutans w
... Show MoreCO2 laser (10.6 μm) is the most often used laser in the oral surgery due to its high absorption by water of the oral tissues. Several benefits of the use of CO2 laser have been reported for oral surgical procedures. This study aims to evaluate the effect of CO2 laser on soft and hard oral tissues (in vitro study). This study was done on fresh tissues from sheep’s head. CO2Surgical Laser with different operation modes was used; 0.2 mm spot size using different laser parameters on the tongue, and bone making holes, incisions and cutting. The depths and widths of holes and incisions were measured using endodontic file under magnification. The speed of incisions was calculated and the required time for cutting was measured using sport clo
... Show MoreBenign prostate hyperplasia (BPH), non-cancerous enlargement of prostate, is the most prevalent disease entity in elderly men. BPH affects 40% of men after the age of 60year worldwide. BPH causes problems for patients with significant lower urinary tract obstructive symptoms, if not responding to medical therapy, surgical intervention is instituted. One method of the treatment of symptomatic BPH is laser prostatectomy. The understanding of tissue effects by laser radiation is very important for the safe clinical application of laser. Objective: study the 2100 nm Ho: YAG laser gross tissue effects in the prostate at different laser dose settings in an vitro model prostate tissue samples harvested from same specimen of open surgery prostat
... Show MoreLaser assisted skin wound closure offers many distinct advantages over conventional closure
techniques. The objective of this in vitro experimental study, carried out at the Institute of Laser for
Postgraduate Studies/Baghdad University, was to determine the effectiveness of 980 nm diode laser in
welding of human skin wounds. Multiple 3-4 cm long full thickness incisions in a specimen of human
skin obtained from the discarded panniculus of an Abdominoplasty operation were tried to be laser
welded using a 4 mm spot diameter laser beam from a 980 nm diode laser at different laser parameters
and modes of action. The tensile strength at the weld site was analyzed experimentally. Although laser
assisted wound welding did
The purpose of this work was to study the effects of the Nd:YAG laser on exposed dentinal
tubules of human extracted teeth using a scanning electron microscope (SEM). Eighty 2.5mm-thick
slices were cut at the cementoenamel junction from 20 extracted human teeth with an electric saw. A
diamond bur was used to remove the cementum layer to expose the dentinal tubules. Each slice was
sectioned into four equal quadrants and the specimens were randomly divided into four groups (A to D ).
Groups B to D were lased for 2 mins using an Nd:YAG laser at 6 pulses per second at energy outputs of
80 , 100 and 120 mJ. Group A served as control. Under SEM observation, nonlased specimens showed
numerous exposed dentinal tubules. SEM o
A total of 60 cotton swabs are collected from patients suffering from burn wound and surgical site infections admitted to Baghdad Teaching Hospital and Burn Specialist Hospital in Baghdad city during 9/2013 to 11/2013. All cotton swabs are cultured initially on blood agar and MacConkey agar and subjected for standard bacteriological procedures for bacteriological diagnosis. Twenty samples out of sixty are identified as Pseudomonas aeruginosa by conventional methods. The results of antibiotic susceptibility test illustrate that the antibiotics resistance rate of Pseudomonas aeruginosa isolates is as follows:100% (2020) for ceftriaxone, cefepime and carbencillin, 70% (14/20) for amikacin, 65%(13/20) for tobramycin, ceftazidim and gentamycin,
... Show MoreThe effect of 532nm Diode Pumped Solid State (DPSS) laser at power density of 5.234 W/cm2 on the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus was evaluated. These bacteria were isolated from samples taken from burn and infected wound areas of 55 patients admitted to the burn-wound unit in Al-Kindy teaching hospital in Baghdad during the period from October 2012 to March 2013. Each isolate was identified using microscopic, cultural and biochemical methods. A standard bacterial suspension was prepared for each isolate. Serial dilutions were then prepared and a dilution of 10-5 was selected. Irradiation experiments included four groups: (L-P-) bacterial suspension in saline solution, (L-P+) bacteria
... Show MoreAim: surface modification of titanium using fiber laser 1064 nm to enhance the bond strength to resin cement. Material and Methods: thirty titanium discs of 0.6 cm x 0.3 cm (diameter and thickness respectively) were categorized after preparation into three groups (n=10) as follows: control group with no surface treatment and two test groups were treated with fiber laser after estimation the appropriate parameters in the pilot study which are 81 ns pulse duration, 30,000 Hz frequency, 50 µm spot size and 10,000 mm/s scanning speed and different average power values (10 W and 20 W) depending on the tested group. Titanium discs surface characterization was performed by scanning electron microscope (SEM), a
... Show MoreBackground: The Initial (primary) stability is one of the factors that play an important role in the success of the dental implants. The purpose of this study was to evaluate the initial stability of dental implant with horizontal plate by using five analytical tests: insertion torque, removal torque, resonance frequency analysis, push-in test and pull-out test. Materials and methods: Two different lengths of dental implants (5mm and 10mm) were tested in this study; each dental implant was 4mm in diameter with a square threads shape of 1mm pitch and 0.5mm depth. The crestal area was 4.2mm diameter contained a right angle margin circumferential ring while the apical area was tapered with two self-tapping grooves. In this study, the initial s
... Show MoreIn this work, ZnS thin films have been deposited by developed laser deposition technique on glass substrates at room temperature. After deposition process, the films were annealed at different temperatures (200ºC , 300 ºC and 400ºC ) using thermal furnace.The developed technique was used to obtain homogeneous thin films of ZnS depending on vaporization of this semiconductor material by continuous CO2 laser with a simple fan to ensure obtaining homogeneous films. ZnS thin films were annealed at temperature 200ºC, 300 ºC and 400ºC for (20) minute in vacuum environment. Optical properties of ZnS thin film such as absorbance, transmittance, reflectance, optical band gap, refractive index extinction coefficient and absorption coefficien
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