Evaluation of the split bone technique for lateral ridge augmentation: A retrospective case-control study.

PURPOSE: The aim of this retrospective case-control study was the evaluation of the split bone technique with regard to the occurrence of early complications, implant survival rate, and peri-implant bone resorption. The effect of patient-related factors (gender, age, tobacco consumption), implant location, and the implant system used on bone resorption was analyzed. MATERIALS AND METHODS: Patients treated by means of the split bone technique with autologous bone blocks from the external oblique line in a two-stage grafting procedure were observed for up to 5 years after implant placement. The control group was a randomly selected group of patients with implants inserted without any augmentation procedures. Vertical bone resorption was measured radiographically, implant survival was calculated by means of the Kaplan-Meier procedure, and complications were recorded numerically. RESULTS: A total of 194 augmentations in 164 patients were performed in the 10-year period. One graft was lost due to exposure and infection of the recipient site, and in four cases, severe resorption of the graft prior to implant placement made a second augmentation necessary. Eighty-seven patients with 100 grafts and 173 implants in the study group and 91 patients with 173 implants in the control group participated in the follow-up. Implant survival was 100% in the study group and 98.5% in the control group (P = .262; log-rank test). The median vertical peri-implant bone resorption after 5 years was 0.7 mm in the study group and 0.6 mm in the control group (P = .371; Mann-Whitney U test). In the study group, the difference between male (0.4 mm) and female (0.9 mm) patients was significant at the end of the follow-up period (P = .022). Significant differences were also found between smokers (2.8 mm) and nonsmokers (0.6 mm) after 5 years (P = .002). CONCLUSION: The split bone technique using autogenous bone represents a reliable therapy method with a very low complication rate and an implant survival rate of 100% after 5 years. The technique did not result in any increase in peri-implant bone resorption during the follow-up period. Smoking and gender may negatively influence peri-implant bone resorption when using this technique.

Clinical outcome in periradicular surgery: effect of patient- and tooth-related factors--a multicenter study.

OBJECTIVE: To evaluate the effect of patient- and tooth-related factors on the outcome of apical surgery in a multicenter study. METHOD AND MATERIALS: A total of 281 teeth in 255 patients undergoing periradicular surgery were investigated clinically and radiographically 6 to 12 months postoperatively. RESULTS: The overall success rate was 88.0%. Sex was a significant (P = .024) predictor, with a success rate of 89.8% in females and 84.0% in males. The success rate was significantly higher in patients 31 to 40 years of age. The treatment of premolars resulted in a significantly higher success rate (91.9%) than the treatment of anterior teeth (86.1%, P = .042) and molars (86.4 %, P = .026). The loss of the buccal bone plate and the extension of apical osteolysis to the furcation area in molars resulted in a considerably lower success rate. Lesion size, preoperative pain, tenderness to percussion, fistula, and resurgery were significant factors. CONCLUSION: There are several factors influencing the success rate of apical surgery that must be taken into account when considering apical surgery as a treatment alternative.

The influence of bone substitute materials on the bone volume after maxillary sinus augmentation: a microcomputerized tomography study.

OBJECTIVES: This study aims to evaluate the effect of adding bone substitute materials (BSM) to particulated autogenous bone (PAB) on the volume fraction (Vf) of newly formed bone after maxillary sinus augmentation. MATERIALS AND METHODS: Thirty healthy patients undergoing maxillary sinus augmentation were included. PAB (N = 10), mixtures of PAB and beta-tricalciumphosphate (PAB/ß-TCP) (N = 10), as well as PAB and ß-TCP and hydroxyapatite (PAB/HA/ß-TCP) (N = 10) were randomly used for sinus augmentation. A sample of the graft material was maintained from each patient at time of maxillary sinus augmentation, and Vfs of the PAB and/or BSM in the samples were determined by means of microcomputerized tomography (µ-CT). Five months later, samples of the grafted areas were harvested during implantation using a trephine bur. µ-CT analysis of these samples was performed, and the Vf of bone and BSM were compared with the data obtained 5 months earlier from the original material. RESULTS: The mean Vf of the bone showed a statistically significant increase (p < 0.05) in all groups after a healing period of 5 months without statistically significant difference between the groups. CONCLUSIONS: With regard to the increase of bone volume, it is not relevant if PAB is used alone or combined with ß-TCP or HA/ß-TCP. CLINICAL RELEVANCE: The amount of PAB and associated donor site morbidity may be reduced by adding BSM for maxillary sinus augmentation.

The influence of substitute materials on bone density after maxillary sinus augmentation: a microcomputed tomography study.

PURPOSE: To evaluate whether adding bone substitute materials to autogenous particulated bone (PAB) might have an effect on the density of the grafted bone after maxillary sinus augmentation. MATERIALS AND METHODS: Thirty healthy patients undergoing lateral antrostomy were included. Sinuses were augmented at random with PAB (n=10) (control group); a mixture of PAB and beta-tricalcium phosphate (Β-TCP) (n=10) (experimental group); or a mixture of PAB, Β-TCP, and hydroxyapatite (HA) (n=10) (experimental group). A sample of each graft material was obtained at time of maxillary sinus augmentation, and microcomputed tomography (Μ-CT) analyses were performed. Five months later, samples of the augmented areas (n=23) were harvested by means of a trephine bur, and Μ-CT analyses of these samples were performed. Density values for the bone were compared to the data obtained 5 months before from the original material. RESULTS: All groups showed increasing density values after a healing time of 5 months. Because of a high dropout rate, the sample size was too small to compare the groups statistically. CONCLUSIONS: Bone density increased after maxillary sinus augmentation for both PAB alone or in combination with substitute materials based on HA and/or Β-TCP particles. A larger sample size and a split-mouth design would help to reliably reveal significant differences between the single materials.

Three-dimensional analysis of bone formation after maxillary sinus augmentation by means of microcomputed tomography: a pilot study.

PURPOSE: Although many studies have analyzed the suitability of different grafting materials for maxillary sinus augmentation by means of histomorphometry in conventional histologic strains, the three-dimensional (3D) structure and remodeling of these grafts after healing beneath the sinus membrane remain unclear. The aim of the present study was to determine whether microcomputed tomography is a suitable method to evaluate the 3D structure and remodeling of grafts after sinus floor augmentation. MATERIALS AND METHODS: Sinus floor augmentation was performed in five patients using autogenous bone (AB) alone, AB and beta-tricalcium phosphate (b-TCP, Cerasorb), AB and b TCP/hydroxyapatite (HA) (BoneCeramic), AB and calcium carbonate (Algipore), and AB and HA (PepGen). Specimens from the grafted sites were harvested by means of a trephine bur 5 to 16 months after maxillary sinus augmentation. Microcomputed tomography of these specimens was performed with a nominal isotropic resolution of 6 x 6 x 6 µm² voxel size. After segmentation, 3D images were reconstructed, and the distribution of bone and substitute material was evaluated by means of volumetric and density measurements. RESULTS: In all images, both bone and substitute material could clearly be identified. The connectivity of trabeculae surrounding the substitute material was visible in the 3D reconstructions. Volumetric evaluation such as total bone volume, volume of substitute material, and trabecular thickness and spacing revealed differences between the different grafting materials. CONCLUSION: Microcomputed tomography is a promising method to evaluate the 3D structure of grafts after sinus floor augmentation with autogenous bone and bone substitute materials.

Clinical evaluation of a modified marginal sulcular incision technique in endodontic surgery.

The authors evaluated periodontal parameters following apical surgery using a new marginal sulcular incision. In 65 cases, surgical access was achieved by means of a sulcular incision technique without the involvement of the adjacent periodontia and the interproximal papillae and in 33 cases by means of a submarginal trapezoidal technique. Periodontal parameters (probing pocket depth, gingival recession, clinical attachment loss, and tooth mobility [periotest]) were recorded at baseline and after 6 months. Scar formation and the loss of papilla height were evaluated photographically. No significant changes in the attachment level and no loss of papilla height were found in either group. A slight gingival recession (0.2 +/- 0.4 mm) corresponding to the decrease in pocket depths occurred on the buccal aspect with the sulcular incision. Tooth mobility was significantly increased in both groups immediately and 6 months after surgery. Scar formation was more unfavorable with the submarginal incision.

Clinical efficacy of semiconductor laser application as an adjunct to conventional scaling and root planing.

BACKGROUND AND OBJECTIVES: The aim of the in vitro study was to examine the clinical efficacy of semiconductor laser periodontal pocket irradiation as an adjunct to conventional scaling and root planing. MATERIALS AND METHODS: Twenty-two healthy patients with a need of periodontal treatment (15 women, 7 men, mean age 45.0 +/- 10.8 years) with at least four teeth in all quadrants, were included. All of them underwent a conventional periodontal treatment including scaling and root planing. Using a split mouth design, two randomly chosen quadrants (one upper and the corresponding lower one) were subsequently treated with an 809 nm GaAlAs laser operated at a power output of 1.0 Watt using a 0.6 mm optical fiber. The teeth in the control quadrants were rinsed with saline. The clinical outcome was evaluated by means of plaque index (PI), gingival index (GI), bleeding on probing (BOP), sulcus fluid flow rate (SFFR), Periotest (PT), probing pocket depth (PPD), and clinical attachment loss (CAL) at baseline and at 3 months after treatment. A total of 492 teeth in both groups were evaluated and differences between the laser and the control teeth were analyzed using the Wilcoxon test (P < 0.05). RESULTS: Teeth treated with the laser revealed a significantly higher reduction in tooth mobility, pocket depth, and clinical attachment loss. Twelve percent of the teeth in the laser group showed an attachment gain of 3 mm or more, compared to 7% in the control group. An attachment gain of 2-3 mm was found in 24% of the teeth in the laser group and 18% in the control group. No significant group differences, however, could be detected for the plaque index, gingival index, bleeding on probing, and the sulcus fluid flow rate. CONCLUSIONS: The higher reduction in tooth mobility and probing depths is probably not predominantly related to bacterial reduction in the periodontal pockets but to the de-epithelization of the periodontal pockets leading to an enhanced connective tissue attachment. The application of the diode laser in the treatment of inflammatory periodontitis at the irradiation parameters described above is a safe clinical procedure and can be recommended as an adjunct to conventional scaling and root planing.

In vitro evaluation of the biocompatibility of contaminated implant surfaces treated with an Er : YAG laser and an air powder system.

Titanium platelets with a sand-blasted and acid-etched surface were coated with bovine serum albumin and incubated with a suspension of Porphyromonas gingivalis (ATCC 33277). Four groups with a total of 48 specimens were formed. Laser irradiation of the specimens (n = 12) was performed on a computer-controlled XY translation stage at pulse energy 60 mJ and frequency 10 pps. Twelve specimens were treated with an air powder system. After the respective treatment, human gingival fibroblasts were incubated on the specimens. The proliferation rate was determined by means of fluorescence activity of a redox indicator (Alamar Blue Assay) which is reduced by metabolic activity related to cellular growth. Proliferation was determined up to 72 h. Contaminated and non-treated as well as sterile specimens served as positive and negative controls. Proliferation activity was significantly (Mann-Whitney U-test, P < 0.05) reduced on contaminated and non-treated platelets when compared to sterile specimens. Both on laser as well as air powder-treated specimens, cell growth was not significantly different from that on sterile specimens. Air powder treatment led to microscopically visible alterations of the implant surface whereas laser-treated surfaces remained unchanged. Both air powder and Er : YAG laser irradiation have a good potential to remove cytotoxic bacterial components from implant surfaces. At the irradiation parameters investigated, the Er : YAG laser ensures a reliable decontamination of implants in vitro without altering surface morphology.

Antimicrobial efficacy of semiconductor laser irradiation on implant surfaces.

PURPOSE: This study was conducted to investigate the antimicrobial effect of an 809-nm semiconductor laser on common dental implant surfaces. MATERIALS AND METHODS: Sandblasted and acid-etched (SA), plasma-sprayed (TPS), and hydroxyapatite-coated (HA) titanium disks were incubated with a suspension of S. sanguinis (ATCC 10556) and subsequently irradiated with a gallium-aluminum-arsenide (GaAlAs) laser using a 600-microm optical fiber with a power output of 0.5 to 2.5 W, corresponding to power densities of 176.9 to 884.6 W/cm2. Bacterial reduction was calculated by counting colony-forming units on blood agar plates. Cell numbers were compared to untreated control samples and to samples treated with chlorhexidine digluconate (CHX). Heat development during irradiation of the implants placed in bone blocks was visualized by means of shortwave thermography. RESULTS: In TPS and SA specimens, laser irradiation led to a significant bacterial reduction at all power settings. In an energy-dependent manner, the number of viable bacteria was reduced by 45.0% to 99.4% in TPS specimens and 57.6% to 99.9% in SA specimens. On HA-coated disks, a significant bacterial kill was achieved at 2.0 W (98.2%) and 2.5 W (99.3%) only (t test, P < .05). For specimens treated with CHX, the bacterial counts were reduced by 99.99% in TPS and HA-coated samples and by 99.89% in SA samples. DISCUSSION: The results of the study indicate that the 809-nm semiconductor laser is capable of decontaminating implant surfaces. Surface characteristics determine the necessary power density to achieve a sufficient bactericidal effect. The bactericidal effect, however, was lower than that achieved by a 1-minute treatment with 0.2% CHX. The rapid heat generation during laser irradiation requires special consideration of thermal damage to adjacent tissues. CONCLUSION: No obvious advantage of semiconductor laser treatment over conventional methods of disinfection could be detected in vitro.

Residual ridge resorption in the edentulous maxilla in patients with implant-supported mandibular overdentures: an 8-year retrospective study.

PURPOSE: This retrospective study radiologically investigated alveolar bone resorption in the edentulous maxilla in patients with implant-supported mandibular overdentures. MATERIALS AND METHODS: This study consisted of 35 healthy, completely edentulous patients with a mean age of 59.7 years. They had received two implants between the mental foramina. New bar-retained mandibular overdentures and maxillary complete dentures were fabricated. Standardized panoramic radiographs taken subsequent to loading and at annual recall visits for up to 8 years were measured for alveolar bone loss in the maxilla. Bone areas and areas of reference not subject to resorption were measured with a planimetry program. The proportional value between both was expressed as a ratio (R). Bone loss was expressed as a change in R between two time points. Differences in the resorption rate between the anterior and posterior parts of the maxilla were investigated. RESULTS: Residual ridge resorption continued during the follow-up period and revealed high individual variability. With a range of 5% to 11% (median) loss in the original bone height, it was significantly (P < .031) more pronounced in the anterior than posterior maxilla (2% to 7%) from the second through eighth years. Regression analysis of the medians revealed a relatively high correlation between time and bone loss in both anterior and posterior parts of the maxilla. CONCLUSION: The anterior anchorage of mandibular overdentures by means of two implants and an ovoid bar was associated with slightly higher resorption in the anterior than in the posterior part of the edentulous maxilla.

Effect of low-level GaAlAs laser irradiation on the proliferation rate of human periodontal ligament fibroblasts: an in vitro study.

AIM: The aim of this in vitro study was to evaluate a potential stimulatory effect of low-level laser irradiation on the proliferation of human periodontal ligament fibroblasts (PDLF). MATERIALS AND METHODS: PDLF obtained from third molar periodontal ligaments were cultured under standard conditions and spread on 96-well tissue culture plates. Subconfluent monolayers were irradiated with an 809-nm diode laser operated at a power output of 10 mW in the continuous wave (cw) mode at energy fluences of 1.96-7.84 Jcm-2. The variable irradiation parameters were the time of exposure (75-300 s per well) and the number of irradiations (1-3). After laser treatment, the cultures were incubated for 24 h. The proliferation rate of the lased and control cultures was determined by means of fluorescence activity of a reduction-oxidation (REDOX) indicator (Alamar Blue Assay) added to the cell culture. Proliferation, expressed in relative fluorescence units (RFU), was determined 24, 48 and 72 h after irradiation. RESULTS: The irradiated cells revealed a considerably higher proliferation activity than the controls. The differences were significant up to 72 h after irradiation (Mann-Whitney U-test, p<0.05). CONCLUSION: A cellular effect of the soft laser application is clearly discernible. Clinical studies are needed to evaluate whether the application of low-level laser therapy might be beneficial in regenerative periodontal therapy.

Temperature changes induced by 809-nm GaAlAs laser at the implant-bone interface during simulated surface decontamination.

The aim of the study was to investigate temperature changes at the implant-bone interface during simulated implant surface decontamination with a 809-nm gallium-aluminium-arsenid (GaAlAs) semiconductor laser. Stepped cylinder implants with a diameter of 3.8 mm and a length of 11 mm with two different surfaces (sand-blasted and acid etched, and hydroxyapatite-coated) were inserted into bone blocks cut from freshly resected pig femurs. Access holes of 0.5 mm were drilled into the bone, to allow K-type thermocouples to contact periimplant bone in different parts of the cavity. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. A 600-micrometer optic fiber was used at a distance of 0.5 mm from the implant surface. Power output varied between 0.5 and 2.5 W in the continuous wave mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. Temperature elevations during irradiation were registered for a period of 120 s. In mean, the critical threshold of 47 degrees C was exceeded after 9.0 s at 2.5 W, 12.5 s at 2.0 W, 18.0 s at 1.5 W and 30.5 s at 1.0 W. Surface characteristics did not have a significant effect on temperature elevations. In an energy-dependent manner, implant surface decontamination with an 809-nm GaAlAs laser must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.

Bactericidal effect of the Er:YAG laser on dental implant surfaces: an in vitro study.

BACKGROUND: The aim of the in vitro study was to examine the bactericidal effect of an Er:YAG laser on common dental implant surfaces. METHODS: Seventy-two titanium platelets with 3 different surfaces--sandblasted and acid-etched (SA), titanium plasma-sprayed (TPS), and hydroxyapatite-coated (HA)--were incubated with a suspension of Streptococcus sanguinis (ATCC 10556). Irradiation at pulse energies of 60 and 120 mJ and a frequency of 10 pps was performed on a computer-controlled XY translation stage. After laser treatment the specimens were sonicated and the bacterial growth examined by counting colony forming units on blood agar plates. Temperature elevations during irradiation were investigated using K-type thermocouples. Laser treated implant surfaces were analyzed by means of electron microscopy. RESULTS: Compared to non-irradiated specimens, mean bacterial reductions of 99.51% (SA), 98.39% (HA), and 99.6% (TPS) at a pulse energy of 60 mJ and 99.92% (SA), 99.85% (HA), and 99.94% (TPS) at 120 mJ were calculated. At these laser parameters, no excessive temperature elevations or morphological implant surface alterations were detected. CONCLUSIONS: Even at low energy densities, the Er:YAG laser has a high bactericidal potential on common implant surfaces. Clinical studies are justified to evaluate the applicability and efficacy of the Er:YAG laser in the treatment of peri-implantitis.

Temperature changes at the implant-bone interface during simulated surface decontamination with an Er:YAG laser.

PURPOSE: This study investigated temperature changes at the implant-bone interface during simulated implant surface decontamination with an Er:YAG laser. MATERIALS AND METHODS: Stepped cylinder implants with three different surfaces (titanium plasma sprayed, sandblasted and acid etched, and hydroxyapatite coated) were placed in bone blocks cut from freshly resected pig femurs. An artificial periimplant bone defect with a size of 6 mm2 provided access for laser irradiation in the coronal third of the implant. A 540-pm periimplantitis application tip was used at a distance of 0.5 mm from the implant surface. Pulse energy was varied between 60 and 120 mJ at 10 pps. The bone block was placed into a 37 degrees C water bath to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a digital meter were used to register temperature changes at three levels of the periimplant bone. RESULTS: The temperature at the implant-bone interface did not exceed 47 degrees C after 120 seconds of continuing laser irradiation. Temperature elevations were significantly higher at the hydroxyapatite-coated implants than in the two titanium surface groups (P < .001). CONCLUSION: Decontamination of implant surfaces by means of the Er:YAG laser did not excessively heat the periimplant bone within the energy range investigated. This technique therefore seems clinically safe, at least when used with the surfaces studied.

Low level 809-nm diode laser-induced in vitro stimulation of the proliferation of human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: The authors investigated the effects of low level laser irradiation on the proliferation rate of human gingival fibroblasts (HGF) in vitro. STUDY DESIGN/MATERIALS AND METHODS: HGF were obtained from gingival connective tissue explants and cultured under standard conditions. 110 cell cultures in their logarithmic growth phase were spread on 96-well tissue culture plates and were irradiated at energy fluences of 1.96-7.84 J/cm(2). Another 110 cultures served as control. An 809-nm semiconductor laser operated at a power output of 10 mW in the cw-mode was used. The time of exposure varied between 75 and 300 seconds. Laser treatment was performed alternatively once, twice, and three times at a 24-hour interval. After lasing, incubation was continued for 24 hours. The proliferation rate was determined by means of fluorescence activity of a redox indicator added to the cell culture. Proliferation was determined 24, 48, and 72 hours after irradiation and expressed in relative fluorescence units (RFU). RESULTS: The irradiated cells revealed a considerably higher proliferation activity. The differences were highly significant 24 hour after irradiation (Mann-Whitney U-test, P < 0.05) but decreased in an energy-dependent manner after 48 and 72 hour after irradiation. CONCLUSIONS: A cellular effect of the soft laser irradiation on HGF is evident. Its duration, however, seems to be limited. These findings might be clinically relevant, indicating that repeated treatments are necessary to achieve a positive laser effect in clinical applications.

Intrapulpal temperature changes during root surface irradiation with an 809-nm GaAlAs laser.

OBJECTIVE: The aim of this study was to explore, in vitro, whether the irradiation of human root surfaces with a diode laser might induce nonphysiologic intrapulpal temperature elevations and, therefore, jeopardize pulp vitality. STUDY DESIGN: The pulps were removed from human maxillary and mandibular incisors extracted for periodontal reasons. The root canals were enlarged to an apical size #60 file. The teeth were radiographed with standard dental films and a millimeter grid to determine root thickness. The thickness of dentin between the root surface and the pulp in the irradiation areas was 1, 2, and 3 mm. To determine intrapulpal temperature changes during laser irradiation, 0.5-mm K-type thermocouples were inserted. An 809 nm GaAlAs laser with a 400-micron optical fiber was used. The power output varied between 0.5 and 2.5 W in the continuous-wave mode (0 Hz). Irradiation was continued for up to 120 seconds. RESULT: Temperature elevations between 0.5 and 32.0 degrees C were registered in an energy- and time-dependent manner. Dentin thickness had a significant effect on intrapulpal temperature changes (Mann Whitney U test, P <.05), with a thinner dentin layer resulting in higher temperature elevations. CONCLUSION: Diode-laser irradiation may jeopardize pulp vitality. It must be recommended to limit power output to 0.5 W and the time of irradiation to 10 seconds when lasing the root surfaces of lower incisors and first maxillary premolars. With other teeth, a power output of 1.0 W and an exposure time of 10 seconds must not be exceeded to ensure a safe clinical application.

Effect of Nd:YAG, Ho:YAG, Er:YAG, CO2, and GaAIAs laser irradiation on surface properties of endosseous dental implants.

PURPOSE: To analyze potential surface alterations in endosseous dental implants induced by irradiation with common dental lasers. MATERIALS AND METHODS: Sandblasted and acid-etched, plasma-sprayed, hydroxyapatite-coated, and smooth titanium discs were irradiated using Nd:YAG, Ho:YAG, Er:YAG, CO2, and GaAIAs lasers at various power settings. The specimens were examined by scanning electron microscopy and energy dispersive spectroscopy. RESULTS: In an energy-dependent manner, the pulsed YAG lasers induced partial melting, cracking, and crater formation on all 4 surfaces. Within the energy range applied, the CO2 laser caused surface alterations on the hydroxyapatite and plasma coatings as well as in the acid-etched surface. GaAIAs laser irradiation did not damage any of the surfaces. Energy dispersive spectroscopy revealed an altered chemical compound of the surfaces with regard to titanium, oxygen, and silicon. DISCUSSION: The clinical application of most common dental laser systems can induce implant surface alterations. Relevant factors are not only the laser system and power setting, but also the application system. CONCLUSION: The results of the study indicate that Nd:YAG and Ho:YAG lasers are not suitable for use in decontamination of implant surfaces, irrespective of the power output. With the Er:YAG and CO2 laser, the power output must be limited so as to avoid surface damage. The GaAIAs laser seems to be safe as far as possible surface alterations are concerned.

Effect of simulated CO2 and GaAlAs laser surface decontamination on temperature changes in Ti-plasma sprayed dental implants.

BACKGROUND AND OBJECTIVE: To investigate and compare temperature elevations at the implant-bone interface during simulated implant surface decontamination with a CO2 and a GaAlAs laser. STUDY DESIGN/MATERIALS AND METHODS: Stepped cylinder implants (Frialit 2) Friadent GmbH, Mannheim, Germany) with a Titanium plasma sprayed surface were inserted into bone blocks cut from pig femurs. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. Both lasers were operated at 1.0-2.5 W in the cw-mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a digital meter were used to register temperature changes at the periimplant bone. RESULTS: In mean, the critical threshold of 47 degrees C was exceeded after 8 seconds at a power output of 2.5 W, 13 seconds at 2.0 W, 18 seconds at 1.5 W, and 42 seconds at 1.0 W with the GaAlAs laser and 15 seconds (2.5 W), 23 seconds (2.0 W), 35 seconds (1.5 W), and 56 seconds (1.0 W) with the CO2 laser. At equal energy fluence, GaAlAs laser irradiation induced significantly higher temperature elevations than CO2 laser irradiation. CONCLUSIONS: In an energy dependent manner implant surface decontamination with both laser types must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.