Slow drilling speeds for single-drill implant bed preparation. Experimental in vitro study.

AIMS: To evaluate the real-time bone temperature changes during the preparation of the implant bed with a single-drill protocol with different drill designs and different slow drilling speeds in artificial type IV bone. MATERIALS AND METHODS: For this experimental in vitro study, 600 implant bed preparations were performed in 10 bovine bone disks using three test slow drilling speeds (50/150/300 rpm) and a control drilling speed (1200 rpm). The temperature at crestal and apical areas and time variations produced during drilling with three different drill designs with similar diameter and length but different geometry were recorded with real-life thermographic analysis. Statistical analysis was performed by two-way analysis of variance. Multiple comparisons of temperatures and time with the different drill designs and speeds were performed with the Tukey's test. RESULTS: T Max values for the control drilling speed with all the drill designs (D1 + 1200; D2 + 1200; D3 + 1200) were higher compared to those for the controls for 11 ± 1.32 °C (p < 0.05). The comparison of T Max within the test groups showed that drilling at 50 rpm resulted in the lowest temperature increment (22.11 ± 0.8 °C) compared to the other slow drilling speeds of 150 (24.752 ± 1.1 °C) and 300 rpm (25.977 ± 1.2 °C) (p < 0.042). Temperature behavior at crestal and apical areas was similar being lower for slow drilling speeds compared to that for the control drilling speed. Slow drilling speeds required significantly more time to finish the preparation of the implant bed shown as follows: 50 rpm > 150 rpm > 300 rpm > control (p < 0.05). CONCLUSIONS: A single-drill protocol with slow drilling speeds (50, 150, and 300 rpm) without irrigation in type IV bone increases the temperature at the coronal and apical levels but is below the critical threshold of 47 °C. The drill design in single-drill protocols using slow speeds (50, 150, and 300 rpm) does not have an influence on the thermal variations. The time to accomplish the implant bed preparation with a single-drill protocol in type IV bone is influenced by the drilling speed and not by the drill design. As the speed decreases, then more time is required.

Influence of involuntary cigarette smoke inhalation on osseointegration: a systematic review and meta-analysis of preclinical studies.

There are no studies that have systematically reviewed the influence of involuntary cigarette smoke inhalation (ICSI) on the stability of implants. The aim of the present study was to perform a systematic review and meta-analysis of preclinical studies that assessed the influence of involuntary cigarette smoke inhalation ICSI on osseointegration. Indexed databases (PubMed, Google-Scholar, Scopus, EMBASE, and Web of Knowledge) were searched till September 2017. Titles and abstracts of studies identified using the above-described protocol were independently screened by 2 authors. Full-texts of studies judged by title and abstract to be relevant were independently evaluated for the stated eligibility criteria. Nine studies were included. Six studies showed that ICSI compromised bone area contact around implants. In 4 studies, peri-implant bone mineral density was significantly higher in the control group than among subjects exposed to ICSI. For the effects of ICSI on the osseointegration of dental implants, significant differences could be observed for bone-to-implant contact for test subjects in cancellous (Z=-4.08, p<0.001) and cortical bone (Z=-4.31, p<0.001) respectively. ICSI may negatively influence osseointegration of dental implants. It is imperative to educate patients about the negative effects of passive smoking on dental and systemic health.

Oral Candida carriage and species prevalence in denture stomatitis patients with and without diabetes.

The objective of this study was to assess the oral Candida carriage and species prevalence in denture stomatitis (DS) patients with and without diabetes mellitus (DM). To address the focused question "In patients receiving dentures, how does having diabetes compared to no diabetes influences the carriage and species prevalence of oral Candida?" Indexed databases were explored without time or language restrictions up to and including February 2017. Nine studies were included. In these studies, the number of diabetics ranged between 14 patients and 405 individuals with mean ages ranging between 33 years and 66.4 years. In five studies, the percentage of hyperglycemic patients in the diabetic group ranged from 14.3% to 100%. In one study, all diabetic patients were normoglycemic. Seven studies reported Candida-associated DS to be significantly higher among diabetics than non-diabetics. Candida albicans was the most prevalent species isolated among diabetics and non-diabetics with DS. Denture-wearers with DM are more susceptible to Candida-associated DS as compared to non-diabetics.

Role of local alendronate delivery on the osseointegration of implants: a systematic review and meta-analysis.

There is controversy regarding whether locally delivered alendronate enhances osseointegration. The aim of this systematic review was to assess the role of local alendronate delivery (topical, or as a coating on implant surfaces) in the osseointegration of implants. The focused question was, "Does the local delivery of alendronate affect osseointegration around implants?". To address this question, indexed databases were searched, without time or language restriction, up to and including January 2017. Various combinations of the following key words were used: "alendronate", "bisphosphonates", "osseointegration", and "topical administration". letters to the editor, historic reviews, commentaries, case series, and case reports were excluded. In total, 18 experimental studies were included: alendronate-coated implants were used in 13 of these studies and local delivery in five studies. The results of 11 of the studies showed that alendronate coating increased new bone formation, the bone volume fraction, or bone-to-implant contact (BIC) and biomechanical properties. Results from two studies in which alendronate was administered topically indicated impaired BIC and/or biomechanical fixation around implants. On experimental grounds, local alendronate delivery seems to promote osseointegration. From a clinical perspective, the results in animal models support phase 1 studies in healthy humans (without co-morbidities other than edentulism).

Association between periodontal disease and polycystic ovary syndrome: a systematic review.

The purpose of the present study was to review systematically the association between periodontal diseases (PDs) and polycystic ovary syndrome (PCOS). To address the focused question, 'Is there a relationship between PD and PCOS?' indexed databases were searched up to October 2016 without time or language restrictions using different combinations of the following key words: PCOS, ovarian cysts, PD, periodontitis, gingival diseases and gingivitis. Letters to the Editor, commentaries, historic reviews, case-report, unpublished articles and animal/experimental studies were excluded. Seven case-control studies were included. The number of study participants ranged between 52 and 196 females aged between 15 and 45 years. In three and three studies, proinflammatory cytokines were assessed in gingival crevicular fluid and saliva samples, respectively. In one study, salivary microbes were investigated. All studies reported that a positive association exists between PD and PCOS. In conclusion, there is a positive association between PD and PCOS; however, further well-designed longitudinal controlled clinical trials are needed in this regard. It is recommended that physicians should refer patients with PCOS to oral health-care providers for comprehensive oral evaluation and treatment.

Role of diode lasers in oro-facial pain management.

With the increasing use of low level laser therapy (LLLT) in clinical dentistry, the aim of the present study was to assess the effectiveness of diode lasers in the management of orofacial pain. Indexed databases were searched without language and time restrictions up to and including July 2016 using different combinations of the following key words: oral, low level laser therapy, dental, pain, diode lasers, discomfort and analgesia. From the literature reviewed it is evident that LLLT is effective compared to traditional procedures in the management of oro-facial pain associated to soft tissue and hard tissue conditions such as premalignant lesions, gingival conditions and dental extractions. However, it remains to be determined which particular wavelength will produce the more favorable and predictable outcome in terms of pain reduction. It is highly recommended that further randomized control trials with well-defined control groups should be performed to determine the precise wavelengths of the diode lasers for the management of oro-facial pain. Within the limits of the present review, it is concluded that diode lasers therapy is more effective in the management of oro-facial pain compared to traditional procedures.

Recent updates on electronic cigarette aerosol and inhaled nicotine effects on periodontal and pulmonary tissues.

E-cigarette-derived inhaled nicotine may contribute to the pathogenesis of periodontal and pulmonary diseases in particular via lung inflammation, injurious, and dysregulated repair responses. Nicotine is shown to have antiproliferative properties and affects fibroblasts in vitro, which may interfere in tissue myofibroblast differentiation in e-cig users. This will affect the ability to heal wounds by decreasing wound contraction. In periodontics, direct exposure to e-vapor has been shown to produce harmful effects in periodontal ligament and gingival fibroblasts in culture. This is due to the generation of reactive oxygen species/aldehydes/carbonyls from e-cig aerosol, leading to protein carbonylation of extracellular matrix and DNA adducts/damage. A limited number of studies regarding the effects of e-cig in oral and lung health are available. However, no reports are available to directly link the deleterious effects on e-cigs, inhaled nicotine, and flavorings aerosol on periodontal and pulmonary health in particular to identify the risk of oral diseases by e-cigarettes and nicotine aerosols. This mini-review summarizes the recent perspectives on e-cigarettes including inhaled nicotine effects on several pathophysiological events, such as oxidative stress, DNA damage, innate host response, inflammation, cellular senescence, profibrogenic and dysregulated repair, leading to lung remodeling, oral submucous fibrosis, and periodontal diseases.

Self-perceived oral health and whole salivary immunoglobulin G levels in habitual gutka-chewers and nonchewers.

OBJECTIVE: To assess self-perceived oral health and whole salivary immunoglobulin G (IgG) levels among habitual gutka-chewers and nonchewers (controls). MATERIALS AND METHODS: Fifty gutka-chewers and fifty controls were included. Demographic data and self-perceived oral health status (pain in teeth, pain on chewing, bleeding gums (BG), bad breath, loose teeth and daily oral hygiene protocols) were collected using a questionnaire. Unstimulated whole saliva (UWS) was collected and unstimulated whole salivary flow rate (UWSFR) was determined. Whole salivary IgG levels were determined using standard techniques. Odds ratios were calculated for oral symptoms and group differences in protein levels were compared using one-way analysis of variance (α± <5%). RESULTS: BG was more often reported by gutka-chewers than controls (P < 0.05). There was no significant difference in UWSFR and self-perceived pain in teeth, pain on chewing, bad breath and loose teeth among gutka-chewers and controls. IgG levels were significantly higher among gutka-chewers than controls (P < 0.01). Among gutka-chewers, whole salivary IgG levels were comparable individuals with and without self-perceived oral symptoms. Among controls, IgG levels in UWS were significantly higher among individuals who had BG than those who did not (P < 0.05). CONCLUSIONS: Self-perceived oral health is worse and whole salivary IgG levels are higher in gutka-chewers compared to controls.

Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study.

AIM: The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks. METHODS: Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed. RESULTS: Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P < 0.05). The type of piezosurgical device did not influence thermal variations (P > 0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P < 0.05). CONCLUSIONS: Within the limitations of this in vitro study, it may be concluded that the temperature increases more in piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies.

Comparison of periodontal inflammatory conditions among habitual gutka chewers and betel quid chewers.

OBJECTIVE: The aim was to compare the periodontal inflammatory conditions among habitual gutka chewers and betel quid (BQ) chewers. MATERIAL AND METHODS: Forty-five gutka chewers, 45 BQ chewers and 50 non-chewers (controls) were included. Demographic data regarding age, gender, duration, and frequency of gutka- and BQ-chewing habits and gingival bleeding were collected using a questionnaire. Clinical periodontal parameters [plaque index (PI), bleeding on probing (BOP), probing depth (PD) and clinical attachment loss (AL)] were recorded. Marginal bone loss (MBL) was measured on digital panoramic radiographs. Group differences in periodontal inflammatory parameters were tested using univariate and multivariable analyses (α < 5%). RESULTS: Periodontal inflammatory parameters [PI, BOP, PD (4-6 and >6 mm), clinical AL and MBL] were significantly high in gutka and BQ chewers than controls. There was no significant difference in periodontal inflammatory parameters among gutka and BQ chewers. The odds for gingival bleeding were six times and 13 times higher in gutka and BQ chewers, respectively, compared to controls. Comparison of gutka and BQ chewers did not significantly increase the odds of gingival bleeding. CONCLUSION: Periodontal inflammatory conditions were comparable among habitual gutka and BQ chewers; which suggests that gutka chewers and BQ chewers are equally susceptible to periodontal disease.

Platform switching minimises crestal bone loss around dental implants: truth or myth?

The aim was to assess the role of platform switching (PS) in minimising crestal bone loss around dental implants through a systematic review of the currently available clinical evidence. To address the focused question 'Does PS minimise crestal bone loss compared with non-platform-switched (NPS) implants?', PubMed/Medline and Google Scholar databases were explored from 1986 up to and including December 2013 using the following key words in different combinations: 'bone loss', 'dental implant', 'diameter', 'mandible', 'maxilla' and 'platform switching'. Letters to the Editor, unpublished data, historical reviews, case reports and articles published in languages other than English were excluded. Fifteen clinical studies were included. In seven studies, PS and NPS implants were placed in both the maxilla and mandible. In 13 studies, implants were placed at crestal bone levels whereas in one study, implants were placed supracrestally. Three studies reported the bucco-lingual (or transversal) width of the alveolar ridge which ranged between 7-8 mm. Seven studies reported that implants placed according to the PS concept did not minimise crestal bone loss as compared with NPS implants. 3D-Implant positioning, width of alveolar ridge and control of micromotion at the implant-abutment interface are the more critical factors that influence crestal bone levels than PS.

Expression of nuclear receptors of gingiva in polycystic ovarian syndrome: a preliminary case study.

Oestrogen is mainly responsible for alterations in blood vessels and progesterone stimulates the production of inflammatory mediators. In females, during puberty, ovulation and pregnancy, there is an increase in the production of sex steroid hormones, which results in increased gingival inflammation, characterized by gingival enlargement, increased bleeding and crevicular fluid flow. This article presents a case of a patient who presented with a complaint of gingival swelling and spontaneous bleeding that persisted for more than two months. Her health history documented the recently diagnosed presence of polycystic ovarian syndrome. Clinical examination revealed enlarged painful gingival tissues, which bled when touched. After completion of Phase I therapy, the enlargement did not subside and a biopsy sample was taken. This was compared with another patient who had the same health condition but did not show any gingival enlargement. Testing of tissue samples for oestrogen and progesterone receptors showed the first patient to be positive for oestrogen receptors but negative for progesterone, whereas the control was negative for both. Positive oestrogen receptors suggest that polycystic ovarian syndrome has some effect on the periodontium. The dental consequences of this condition, highly prevalent among young females, are typically ignored. Further studies warrant establishment of a clinical association and future diagnosis.

Hydrogen storage in polymer-functionalized Pd-decorated single wall carbon nanotubes.

Palladium is usually supported on porous materials in the form of nanoparticles. The hydrogen storage capacity of such a system is usually much higher than the separated capacity of the metal (approximately 0.7 H/Pd) and the support. Pd nanoparticles provide a source of hydrogen atoms by dissociation. The atomic hydrogen spills over from the Pd structure to the support via surface diffusion and this phenomenon is known as hydrogen spillover. In this study commercial SWNTs were dispersed in PEG 200 solution. Then the precursor PdCl2 in PEG 200 was added and the whole left to react under stirring with reflux at 200 degrees C for 1 h. Succeeding washings with ethanol and centrifugation followed for several times and finally the sample was dried at 60 degrees C. Through this procedure a 3 wt% Pd loading was achieved whereas the TEM derived nanoparticle size distribution indicated a 50% percentage of Pd nanoparticles with diameter less than 8 nm. Hydrogen isotherms up to 2 MPa were carried out with the gravimetric method. The defined storage capacity of 1.2 wt% at 0.2 MPa was quite satisfactory. However, a 0.2 wt% portion of this storage capacity was attributed to the formation of water molecules through reaction of H atoms with the dissociatively adsorbed oxygen atoms on the Pd nanoparticles. This conclusion was educed from a series of thermal desorption experiments following the H2 adsorption/desorption cycles and regeneration. Through this set of experiments several other important parameters were defined as the temperature for complete hydrogen desorption and the optimum conditions for PEG removal.

Grafting of alginates on UF/NF ceramic membranes for wastewater treatment.

The mechanism of heavy metal ion removal in processes involving multi-layered tubular ultrafiltration and nanofiltration (UF/NF) membranes was investigated by conducting retention experiments in both flow-through and cross-flow modes. The prospect of the regeneration of the membranes through an acidic process was also examined and discussed. The UF/NF membranes were functionalised with alginates to develop hybrid inorganic/organic materials for continuous, single pass, wastewater treatment applications. The challenge laid in the induction of additional metal adsorption and improved regeneration capacity. This was accomplished by stabilizing alginates either into the pores or on the top-separating layer of the membrane. The preservation of efficient water fluxes at moderate trans-membrane pressures introduced an additional parameter that was pursued in parallel to the membrane modification process. The deposition and stabilization of alginates was carried out via physical (filtration/cross-linking) and chemical (grafting) procedures. The materials developed by means of the filtration process exhibited a 25-60% enhancement of their Cd(2+) binding capacity, depending on the amount of the filtered alginate solution. The grafting process led to the development of alginate layers with adequate stability under acidic regeneration conditions and metal retention enhancement of 25-180%, depending on the silane involved as grafting agent and the solvent of silanisation.

In vitro evaluation of the implant abutment connection sealing capability of different implant systems.

This study sought to evaluate the sealing capability of the implant abutment connection of different dental implant systems. Five Nobel Replace select, Straumann and Intra-lock implants of approximately 4.5 mm diameter with their respective abutments were provided by the manufacturers. A calibration curve was determined by placing toluidine blue (TB) increments of 0.1 microL into 1.5 mL of distilled water and recording its absorbance in a spectrophotometer until reaching 0.7 microL. Then, 0.7 microL of TB was placed in the deepest portion of each implant's internal screw, the abutments were adapted to the implant according to the manufacturer's instructions and the specimens were placed in vials with 1.5 mL of distilled water. Spectrophotometric analysis was performed at 1, 3, 6, 24, 48, 72, 96 and 144 h. Statistical analysis was performed by One-way anova at 95% level of significance. The calibration curve was linear with respect to the TB amount in 1.5 microL distilled water (R(2) = 0.9961). All implant abutment systems presented an increase in absorbance as a function of time. As time elapsed in vitro, significantly higher amounts of TB was released from the Straumann and Nobel Replace Select connection systems (P < 0.0001). Leakage was significant between the groups. Despite controlled torquing, the seal between the implant body and the abutment could not be maintained in all three of the systems tested.

Ibuprofen sodium dihydrate, an ibuprofen formulation with improved absorption characteristics, provides faster and greater pain relief than ibuprofen acid.

OBJECTIVE: The objective of this 6-hour study was to compare rate of pain relief, analgesic efficacy and tolerability of a novel ibuprofen formulation, ibuprofen sodium dihydrate, with that of ibuprofen acid in subjects with postoperative dental pain. MATERIAL AND METHODS: The test formulation of ibuprofen sodium dihydrate (256 mg sodium salt) and the reference product both contain 200 mg ibuprofen. Subjects with moderate-to-severe pain after extraction of third molars were randomized to receive two tablets of either ibuprofen sodium dihydrate (198 subjects) or ibuprofen (198 subjects) in this double-blind, multicenter trial. Pain was measured using traditional descriptor scales and onset of analgesia assessed using the stop-watch method. RESULTS: Median time to substantial pain relief occurred 14 minutes earlier in the ibuprofen sodium dihydrate group (p < 0.001). The first sign of pain relief, an increase in relief and time until the pain was half gone occurred significantly earlier and faster in the ibuprofen sodium dihydrate-treated patients (p < 0.02-0.00003). Corresponding numbers needed to treat were in the range 11. Reduction in pain intensity was evident within 5 minutes (p < 0.01) in the ibuprofen sodium dihydrate group compared to 15 minutes in the ibuprofen group. Pain intensity was reduced to half after 30 and 57 minutes in the ibuprofen sodium dihydrate and ibuprofen groups, respectively (p < 0.025). The overall analgesic efficacy in terms of summed pain intensity differences (SPID), total pain relief (TOTPAR) and remedication times in the two groups were similar. Both treatments were well tolerated and no serious events occurred. CONCLUSION: Ibuprofen sodium dihydrate provides faster and more efficacious pain relief during the first hour after intake when compared to a conventional ibuprofen acid formulation. The tolerability profiles are similar.

Present status of immediate loading of oral implants.

PROBLEM: Several conditions must be present to obtain implant integration and long-term clinical success when using the one-stage implant placement procedure with immediate loading. These conditions include (1) primary stability, (2) sufficient bone quality, and (3) elimination of micromovement of the implant before osseous integration is complete. PURPOSE: This report presents the results of research on immediate loading using a new and innovative implant design, Ankylos. METHODS: The author reviewed clinical studies of immediate loaading or oral implants, including two treatment options, removable overdentures and fixed reconstructions. RESULTS: Animal studies have demonstrated that successful osseointegration of Ankylos implants can occur (Figure 2D) when implants are placed and loaded immediately in the presence of some specific conditions. The histological findings involving implants that were placed in humans and immediately loaded showed no fibrous tissue formation (encapsulation). The bone-to-implant contact (osseointegration) was found to be excellent between the immediately-loaded implants and the surrounding alveolar bone. CONCLUSION: The Ankylos implant system with its progressive thread design successfully promotes primary, clinical stability at the time of implant placement. Several animal studies have shown that in implant restorations placed in similar areas of poor bone quality (ie, maxilla and the posterior part of the mandible), the concept of immediate loading can result in long-term clinical success, when loading forces are controlled. Immobilization of the implants and soft diet recommendations that reduce micromovement at the bone-to-implant interface will improve long-term clinical success. In summary, the Ankylos implant is well designed for one-stage placement with immediate loading, as well as for two-stage treatment protocols. Both clinical protocols will result in long-term clinical survival.

Effects of CO2 laser treatment on fibroblast attachment to root surfaces. A scanning electron microscopy analysis.

BACKGROUND: The aim of this study was to analyze the CO2 laser effects on root surfaces affected by periodontal disease in comparison to scaling and root planing for fibroblast attachment. METHODS: Thirty single-rooted human teeth extracted because of advanced periodontal disease were included in this study. A total of 60 specimens, obtained from all selected teeth, were randomly assigned to 3 groups: 1) control (untreated); 2) hand scaling and root planing (SRP); or 3) laser (CO2 defocused pulsed) and ultrasonic scaling. All the specimens were incubated in Petri dishes with fibroblast suspension, and then observed by scanning electron microscopy (SEM). RESULTS: The control group showed the lowest number of attached cells, with no tightly attached fibroblasts. The laser plus scaling group showed the highest number of attached fibroblasts, with the tightly attached fibroblast prevailing. The laser-treated and scaled root specimens did not show any damage or morphologic alteration of the root surfaces. CONCLUSION: CO2 laser treatment in defocused, pulsed mode with a low power of 2W combined with mechanical instrumentation constitutes a useful tool to condition the root surface and increase fibroblast attachment to root surfaces.

Root surface morphological changes after focused versus defocused CO2 laser irradiation: a scanning electron microscopy analysis.

BACKGROUND: Many studies have observed damages to root surfaces treated by CO2 laser in continuous mode with a focused beam. The morphologic changes observed were always associated with temperature increase induced by high energy release. METHODS: The purpose of this study was to analyze by scanning electron microscopy (SEM) the effects of CO2 laser in 2 different modes on root surfaces. Study samples consisted of 30 extracted single-rooted periodontally compromised human teeth. Root specimens were randomly assigned to 3 groups: group A (12) treated with CO2 laser in continuous mode with a focused beam of 0.8 mm; group B (12) treated with CO2 laser in pulsed mode with defocused beam of 4 mm; and group C (6), untreated controls. RESULTS: Group A (continuous mode) showed severe damages to dentin surfaces such as craters and fissures. Group B (defocused mode) did not result in any damages to the root surfaces, showing flat and smooth surfaces with apparent fusion of the smear layer and dentinal tubules almost completely sealed. The untreated control group was characterized by irregular and amorphous surfaces with several shallow depressions. CONCLUSIONS: Although both laser modes resulted in changes to the treated root surface specimens, the changes resulting in a smooth surface from use of defocused pulsed beam may present an advantage in periodontal treatment.

Effects of diode and Nd:YAG laser irradiation on titanium discs: a scanning electron microscope examination.

BACKGROUND: Dental lasers have been recommended for uncovering submerged implants as well as decontaminating implant surfaces when treating peri-implantitis. The aim of this study was to show the possible alterations in titanium disc surfaces using an Nd:YAG or a diode laser. METHODS: Three different titanium discs were used (sandblasted, titanium plasma-sprayed [TPS], and hydroxyapatite [HA] coated) to determine the effects of laser irradiation on these surfaces using a scanning electron microscope (SEM). The discs were either irradiated with a pulsed Nd:YAG laser with a contact handpiece and power settings of 2.0, 4.0, and 6.0 W or with a diode laser at 5.0, 10.0, and 15.0 W power settings and continuous wave (cw) in the contact handpiece. Irradiated areas were compared with control titanium sites which were not lased. The specimens were prepared for SEM examination after the disc irradiation. RESULTS: The SEM examination demonstrated extensive melting in all of the Nd:YAG laser irradiated areas. Damage was seen in all TPS- and HA-coated discs even at the lowest power setting. Loss of porosity, coating microfractures, and a relatively smooth surface were observed. In contrast, the diode laser did not cause any damage or modify the disc surface. Regardless of the power setting, there was no visible difference between lased and non-lased surfaces after cw irradiation with the diode laser. CONCLUSIONS: From these findings, it was concluded that the diode laser (980 nm) does not damage titanium surfaces, which should be of value when uncovering submerged implants and treating peri-implantitis.