Photobiomodulation as an adjunctive therapy for alveolar socket preservation: a preliminary study in humans.

Bone remodeling results in loss of alveolar bone height and thickness. Photobiomodulation (PBM) based on photochemical stimulation by low-intensity lasers emerges as an adjunctive therapy for alveolar socket preservation. Our study aimed to evaluate the effects of PBM therapy on alveolar bone repair. Twenty healthy patients in need of bilateral extraction of lower molars were enrolled in this split-mouth randomized and blind clinical trial. The extraction sites were randomly selected to receive either the PBM therapy with a CW GaAIAs diode laser (808 nm; 0.028 mm2; 0.1 W; 3.6 W/cm2; 89 J/cm2; 2.5 J/point) or no treatment (Control). Bone biopsies were harvested 45 days after the dental extraction and evaluated using micro-computerized tomography (µCT), morphometric, and histological analysis. Data were compared using the paired t test, and the level of significance was set at 5%. Bone surface (p = 0.029), bone surface/total volume (p = 0.028), trabecular number (p = 0.025), and connectivity density (p = 0.029) were higher at the PBM group compared with Control. The histological observations confirmed the µCT findings. PBM samples exhibited higher number of organized and connected bone trabeculae along with higher density of blood vessels than Control. Control samples displayed a dense and highly cellular connective tissue at the central area accompanied by the presence of immature bone trabeculae at the periphery. Our results indicated that the PBM therapy improved the newly bone trabeculae formation and their connectivity which increased bone surface, indicating the positive effect of the laser on alveolar human socket repair.

Effect of Laser Radiation on Infected Sites for the Immediate Placement of Dental Implants.

Objective: The study aims to evaluate the feasibility of erbium-chromium: yttrium-scandium-gallium-garnet (ErCr:YSGG 2780 nm) laser irradiation on infected and/or inflamed post-extraction sites for the immediate placement, and when possible, immediate loading, of endosseous implants. Background: Post-extraction site infection is a serious complication. Surgical and nonsurgical options are available to treat such event, together with various decontamination methods. However, there is still no consensus on which treatment is the most effective. Materials and methods: Sixty-six patients were included in the study for a total of 94 post-extraction implants, inserted in the maxilla and mandible. All patients were eligible for implant therapy, having at least one compromised tooth requiring extraction, along with sign of inflammation and/or infection. Surgery and socket decontamination were performed using an ErCr:YSGG laser. To improve bone healing, Bio-Oss® and resorbable membrane were used in 57 patients. Eleven implants were immediately loaded, whereas 83 were loaded within 3-6 months, depending on the extraction site. Intraoral radiographs were taken at 1, 3, 6, 9, and 12 months from the implant placement to assess the alveolar bone level and treatment's outcome. Albrektsson criteria were chosen to evaluate the treatment success rate. Results: Follow-up went from 6 months to 4 years. Success rate was 94.6% (89/94): three implants failed to integrate due to poor patient compliance, being expelled during the second week, whereas two implants presented factory defects (abutment). No sockets presented signs of residual infection during follow-up. Conclusions: The combination of mechanical, chemical, and laser treatment was proven to be highly effective for the disinfection of post-extraction sites. The ErCr:YSGG laser is a useful tool, not only for his practicality as a surgical device but also as a disinfection tool, granting optimal results after implant surgery.

Utility of High-Intensity Laser Therapy Combined with Photobiomodulation Therapy for Socket Preservation After Tooth Extraction.

Objective: High-intensity laser therapy (HILT) combined with photobiomodulation therapy (PBMT) using a diode or CO2 laser was administered after extraction of the left first molar in rats. Effects on socket preservation (preservation of the alveolar bone and healing time after extraction) were evaluated histopathologically. Background: Irradiation using a diode or CO2 laser has been shown to hasten wound healing, but the effects remain controversial. Methods: Five-week-old male Wistar rats that underwent extraction of the left maxillary first molar were divided into three groups: diode laser irradiation (diode group), CO2 laser irradiation (CO2 group), and no laser irradiation (control group). HILT (27 J) was performed immediately after tooth extraction to enhance blood coagulation, followed by PBMT (0.7 J) 1 day later to enhance healing. Tissues, including the extraction socket, were removed en bloc 3, 5, 7, 10, and 21 days postextraction to determine the morphological characteristics of wound healing and the distribution of myofibroblasts involved in scar formation. Results: In the diode and CO2 groups, new bone formation and cancellous bone maturation were observed at an early stage of wound healing. The number of myofibroblasts was significantly lower in the laser treatment groups than the control (p < 0.001), and both treatment groups had a significantly higher alveolar crest height (p < 0.01), with almost no concavity in the mucosa of the extraction wound. Conclusions: Combined HILT and PBMT following tooth extraction hastened wound healing and preserved alveolar crest height, suggesting a role in socket preservation.

High-frequency pulsed low-level diode laser therapy accelerates wound healing of tooth extraction socket: An in vivo study.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the effects of high-frequency pulsed (HiFP) low-level laser therapy (LLLT) on early wound healing of tooth extraction sockets in rats. STUDY DESIGN/MATERIALS AND METHODS: Bilateral maxillary first molars were extracted from 6-week-old Sprague-Dawley rats. Sockets on the right were treated by HiFP low-level diode laser irradiation (904-910 nm); the left sides served as unirradiated controls. LLLT (0.28 W, 30 kHz, 200-ns pulse, 0.6% duty cycle, 61.2 J/cm2 total power density) was employed immediately after extraction and every 24 hours thereafter. The maxillae including the sockets were resected 3 or 7 days after extraction. Soft-tissue healing was evaluated on days 0, 3, and 7. The bone mineral content (BMC), bone volume (BV), and bone mineral density (BMD) of the extraction sockets were evaluated by microcomputed tomography, and histomorphometric analysis was carried out on day 7. Real-time PCR analysis of osteogenic marker expression and immunohistochemical detection of proliferating cell nuclear antigen (PCNA)-positive cells were performed on day 3. RESULTS: Compared with control sites, the un-epithelialized areas of the extracted sites were significantly reduced by irradiation (P = 0.04), and the BMC, BV, and BMD of laser-treated sites were significantly increased (P = 0.004, 0.006, and 0.009, respectively). On day 7, the mean height of newly formed immature woven bone was higher in laser-treated sites (P = 0.24). On day 3, laser-treated sites showed significantly higher osteocalcin mRNA expression (P = 0.04) and PCNA-positive cell numbers (P = 0.01). CONCLUSION: HiFP low-level diode laser irradiation enhanced soft- and hard-tissue healing of tooth extraction sockets. Lasers Surg. Med. 48:955-964, 2016. © 2016 Wiley Periodicals, Inc.

High-Frequency, Low-Intensity Pulsed Ultrasound Enhances Alveolar Bone Healing of Extraction Sockets in Rats: A Pilot Study.

Most studies of the beneficial effects of low-intensity pulsed ultrasound (LIPUS) on bone healing have used frequencies between 1.0 and 1.5 MHz. However, after consideration of ultrasound wave characteristics and depth of target tissue, higher-frequency LIPUS may have been more effective on superficially positioned alveolar bone. We investigated this hypothesis by applying LIPUS (frequency, 3.0 MHz; intensity, 30 mW/cm(2)) on shaved right cheeks over alveolar bones of tooth extraction sockets in rats for 10 min/d for 2 wk after tooth extraction; the control group (left cheek of the same rats) did not receive LIPUS treatment. Compared with the control group, the LIPUS group manifested more new bone growth inside the sockets on histomorphometric analysis (maximal difference = 2.5-fold on the seventh day after extraction) and higher expressions of osteogenesis-related mRNAs and proteins than the control group did. These findings indicate that 3.0-MHz LIPUS could enhance alveolar bone formation and calcification in rats.

Effect of low-level laser therapy on orthodontic tooth movement into bone-grafted alveolar defects.

INTRODUCTION: The objective of this study was to investigate the effect of low-level laser therapy (LLLT) on the rate of orthodontic tooth movement (OTM) into bone-grafted alveolar defects based on different healing states. METHODS: Ten male beagles were randomly allocated to 3 groups: group C, OTM alone as a control; group G, OTM into the grafted defects; group GL, OTM into the grafted defects with LLLT. The maxillary second premolars were protracted into the defects for 6 weeks, immediately (G-0 and GL-0) and at 2 weeks (G-2 and GL-2) after surgery. The defects were irradiated with a diode laser (dose, 4.5 J/cm(2)) every other day for 2 weeks. The rates of OTM and alveolar bone apposition, and maturational states of the defects were analyzed by histomorphometry, microcomputed tomography, and histology. RESULTS: The total amounts of OTM and new bone apposition rates were decreased by LLLT, with increased bone mineral density and trabecular maturation in the defects. Group GL-2 had the slowest movement with root resorption in relation to less woven bone in the hypermatured defect. CONCLUSIONS: LLLT significantly decreased the rate of OTM into the bone-grafted surgical defects by accelerating defect healing and maturation, particularly when the start of postoperative OTM was delayed.

Micro-computed tomography and histomorphometric analysis of human alveolar bone repair induced by laser phototherapy: a pilot study.

Immediate dental implant placement in the molar region is critical, because of the high amount of bone loss and the discrepancy between alveolar crest thickness and the implant platform. Laser phototherapy (LPT) improves bone repair. The aim of this study was to evaluate the human alveolar bone repair 40 days after molar extraction in patients submitted to LPT. Twenty patients were selected for this randomized controlled clinical trial; 10 underwent LPT (laser group) with a GaAlAs diode laser (808 nm, 100 mW, 0.04 cm(2), 75 J/cm(2), 30s per point, 3 J per point, at five points). The control group patients (n=10) were not irradiated. Forty days later, the tissue formed inside the sockets was analyzed by micro-computed tomography and histomorphometry. Data from the two groups were compared with Student's t-test and Pearson's correlation test. The relative bone volume was significantly higher in the laser group (P<0.0001). The control group showed negative correlations (P<0.01) between number and thickness, and between number and separation of trabeculae, and a positive correlation between thickness and separation of trabeculae. The laser group showed a significant negative correlation between the number and thickness of trabeculae (P<0.01). The results suggest that LPT is able to accelerate alveolar bone repair after molar extraction, leading to a more homogeneous trabecular configuration represented by thin and close trabeculae.

Histologic and Resonance Frequency Analysis of Peri-Implant Bone Healing After Low-Level Laser Therapy: An In Vivo Study.

PURPOSE: To evaluate the effects of low-level laser therapy (LLLT) on peri-implant bone regeneration by means of resonance frequency analysis and histologic analysis of bone-to-implant contact (BIC). MATERIALS AND METHODS: Thirty-two male New Zealand rabbits were randomly divided into four groups of eight animals each, one control group (nonirradiated animals) and three experimental groups that received LLLT (group E5 = 5 J per session; group E10 = 10 J per session; group E20 = 20 J per session). The mandibular left incisor was surgically extracted in all animals, and a nanoparticle-treated-surface osseointegrated implant was placed immediately afterward. The experimental groups were irradiated with aluminum-gallium-arsenide laser diode every 48 hours over a 13-day period for a total of seven sessions. Implant stability quotients (ISQs) were measured at the time of implant placement and 30 days after the last LLLT session. The animals were then euthanized and dissected, and histologic slides of the implant region were obtained for BIC evaluation. RESULTS: Significant differences in ISQ were detected between groups before and after LLLT, with group E20 showing significantly higher values than controls. The percentage of BIC was also significantly higher in group E20 than in control animals. CONCLUSION: Laser therapy at a dose of 20 J per treatment session, based on the irradiation protocol used in this study, was able to significantly increase ISQ values and BIC after implant placement, indicating that laser irradiation effected an improvement in peri-implant bone healing.

Effects of increased low-level diode laser irradiation time on extraction socket healing in rats.

In our previous studies, we confirmed that low-level laser therapy (LLLT) with a 980-nm gallium-aluminum-arsenide diode laser was beneficial for the healing of the alveolar bone in rats with systemic disease. However, many factors can affect the biostimulatory effects of LLLT. Thus, we attempted to investigate the effects of irradiation time on the healing of extraction sockets by evaluating the expressions of genes and proteins related to bone healing. The left and right first maxillary molars of 24 rats were extracted. Rats were randomly divided into four groups in which extraction sockets were irradiated for 0, 1, 2, or 5 min each day for 3 or 7 days. Specimens containing the sockets were examined using quantitative real-time reverse transcription polymerase chain reaction and western blotting. LLLT increased the expressions of all tested genes, Runx2, collagen type 1, osteocalcin, platelet-derived growth factor-B, and vascular endothelial growth factor, in a time-dependent manner. The highest levels of gene expressions were in the 5-min group after 7 days. Five minutes of irradiation caused prominent increases of the expression of all tested proteins after both 3 and 7 days. The expression level of each protein in group 4 was higher by almost twofold compared with group 1 after 7 days. Laser irradiation for 5 min caused the highest expressions of genes and proteins related to bone healing. In conclusion, LLLT had positive effects on the early stages of bone healing of extraction sockets in rats, which were irradiation time-dependent.

Combination of LED light and platelet-derived growth factor to accelerate dentoalveolar osteogenesis.

AIM: This study aimed to evaluate the adjunctive effect of LED light in platelet-derived growth factor (PDGF)-aided dentoalveolar osteogenesis. MATERIAL AND METHODS: Full-thickness osseous wounds were created on rat maxillae and were either unfilled or filled with poly-(D,L-lactide) and poly-(D,L-lactide-co-glycolide) microspheres encapsulating PDGF. Animals received daily 660 ± 25 nm LED light irradiation at 0, 10 (LD), or 20 (HD) J/cm(2) , were killed at days 4-28 (n = 6/group/time) and evaluated by microcomputed tomography (micro-CT), histology, and the expressions of osteopontin and tartrate-resistant acid phosphatase (TRAP). RESULTS: Greater osteogenesis was noted in the PDGF-treated defects at day 14. Under the LED light irradiation, osteogenesis was significantly greater in both LD and HD groups of the non-PDGF-treated defects, but only in the LD group of the PDGF-treated defects. No significant differences in osteogenesis among groups were noted at day 28. Greater bone marrow space was noted in the LED light-irradiated specimens, especially in the PDGF-treated defects at both time points. Osteopontin was significantly promoted in the LD group at both time points, and TRAP was significantly promoted in all LED light-irradiated groups at day 28. CONCLUSION: LED light could an adjunct to promote early PDGF-aided dentoalveolar osteogenesis by facilitating the osteoblast-osteoclast coupling.

Can plasma rich in growth factors improve healing in patients who underwent radiotherapy for head and neck cancer? A split-mouth study.

OBJECTIVES: The objective of this study was to identify surgical protocols that can improve mucosal healing and postextraction socket closure in patients who underwent radiation therapy for head and neck cancer. METHODS: The study was designed as a prospective split-mouth trial on 20 patients who needed bilateral paired dental extractions. On the side directly impacted by radiation, chosen to be the study side, the sockets were filled with plasma rich in growth factors (PRGF), whereas, on the other side (control), they were allowed to undergo natural healing. Outcome variables were residual socket volume (RSV), healing index (HI), pain, and postsurgical complications as measured at the 2 sides at the 4 follow-up sessions (up to 30 days after the extraction). Continuous variables were analyzed with Wilcoxon (when matched) or Mann-Whitney (when independent) test; categorical variables, with Chi-squared or Fisher test. Statistical significance was set at P < 0.05. Correlation was estimated with Pearson linear correlation coefficient. RESULTS: The PRGF side showed statistically significant better values for RSV and HI at all checkups and no postoperative complications. The control side had a slower healing and 2 cases of bone exposure, which were successfully cured with PRGF application. The RSV on the 21st day after the extraction was correlated with the dose received but not with the time since radiotherapy. CONCLUSIONS: Plasma rich in growth factors proved to be effective in the management of patients with a history of head and neck radiotherapy, accelerating and fostering mucosal healing and avoiding postextraction bone exposures.

Assessment of the systemic effects of low-level laser therapy (LLLT) on thyroid hormone function in a rabbit model.

The aim of this study was to assess the effects of low-level laser therapy (LLLT) applied to a dental extraction socket on thyroid gland function in a rabbit model, based on serum triiodothyronine and thyroxine levels. Sixteen male New Zealand rabbits were randomly distributed into two groups: a control group (non-irradiated animals) and an experimental group (irradiated animals: one irradiation point in the extraction socket of the lower incisor). Animals in the experimental group were irradiated with an aluminium gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 40 mW, CW laser), for 13 days, every 48 h, at a dose of 6 J/cm(2) per session, resulting in a total dose of 42 J/cm(2). Serum triiodothyronine and thyroxine levels were measured in both groups before extraction and on the last day of observation (day 15). There were no statistically significant differences between the groups in pre- and post-irradiation triiodothyronine and thyroxine values. With the irradiation protocol used in this study, LLLT did not affect thyroid function in rabbits as assessed by circulating serum triiodothyronine and thyroxine levels.

Evaluation of socket healing in irradiated rats after diode laser exposure (histological and morphometric studies).

OBJECTIVE: The purpose of this study is to evaluate the effect of low-level laser therapy (LLLT) in enhancing bone repair in irradiated sockets of albino rats. DESIGN: Thirty male Swiss Albino rats ranging from 120 to 150 g were used in this study. The animals were subjected 6 gray gamma radiations. Three days post irradiation, right and left mandibular first molars were extracted. The sockets of the left sides were irradiated by (GaAIAs) diode laser device immediately after extraction, while the sockets of the right side were not exposed to the laser and served as control. The rats were randomly assigned into three groups (10 rats each) according to the date of sacrifice, 3, 7 and 10 days into groups I, II and III, respectively. The two sides of each mandible were separated. Each group was further subdivided into subgroups A and B (10 specimens each), where A represents the right side of the mandible and B represents the left side. The specimens were stained with hematoxylin and eosin, and Masson's trichrome. RESULTS: LLLT accelerated bone healing, while, radiotherapy induced delay of bone healing along the three experimental groups. This acceleration was assessed histologically by the presence of mature collagen fibre bundles and early new bone formation in the lased groups. Histomorphometric analysis revealed an increase in the area percentage of bone trabeculae in the lased sockets compared to the control ones in group II. This increase was statistically significant (p = 0.0274). The increase in the area percentage of bone trabeculae between the lased and control sockets of group III was statistically insignificant (p = 0.1903). CONCLUSIONS: In a rat model application of LLLT with a GaAIAs diode laser device can enhance bone healing and mineralisation in sockets subjected to gamma radiation.

Brachytherapy-mediated bone damage in a rat model investigating maxillary osteoradionecrosis.

OBJECTIVES: To assess clinical and radiologic findings from targeted radiotherapy to the rat maxilla and to compare findings with a recently developed rat model of mandibular osteoradionecrosis (ORN). DESIGN: A prospective, controlled animal study. SUBJECTS: Ten male Sprague-Dawley rats were divided into an experimental group receiving catheter-assisted high-dose-rate brachytherapy (n = 6) and a control group with catheter-assisted sham therapy (n = 4). INTERVENTIONS: The second left maxillary molar was extracted 1 week after radiation, and the maxilla was harvested 3 weeks after dental extraction. MAIN OUTCOME MEASURE: We used a standardized method with micro-computed tomography to determine the ratio of bone volume to total volume of the dental extraction socket. RESULTS: On the gross clinical examination, all rats had mucosal coverage of the dental extraction site, whereas only the brachytherapy group demonstrated scarring of the mucosa. The median bone volume to total volume was 0.21 for the brachytherapy group and 0.49 for the control group (P = .01). CONCLUSIONS: Similar to the mandible, the maxilla is susceptible to radiogenic bone injury as demonstrated by the significant decrease in bone volume of the radiated dental extraction socket. Despite radiologic similarities to mandibular ORN in the rat model, the maxilla demonstrated a more benign clinical course with a complete absence of bone exposure. Differences in the maxillary bone and microenvironment of the maxilla compared with the mandible may explain the subclinical response to radiation and lower incidence of maxillary ORN seen in patients. This maxillary model can be combined with our high-dose-rate mandibular ORN model to investigate these differences and better understand ORN.

Platelet rich plasma for the prevention of osteoradionecrosis. A double blinded randomized cross over controlled trial.

Osteoradionecrosis of the jaws is a complication of radiotherapy and controversy remains about the management of teeth in the field of radiotherapy. Platelet rich plasma has been advocated in multiple surgical sites, both bone and soft tissue, to promote healing and reduce complications. A randomized double blinded controlled trial was performed on patients receiving bilateral radiotherapy that affected the mandible who required pre treatment dental extractions. One side received platelet rich plasma and the other acted as a control. Twenty-two patients were recruited over 12 months and over a 5-year period following treatment three developed osteoradionecrosis (14%). Platelet rich plasma failed to show any benefit in the prevention of osteoradionecrosis. Nor was there any benefit in pain scores or mucosal healing on sides that were treated with platelet rich plasma. Platelet rich plasma fails to show a benefit in the prevention of osteoradionecrosis. The rate of osteoradionecrosis is high compared to other published series and the prophylactic removal of molar teeth should be questioned as a preventative measure.

Effect of 980-nm GaAlAs diode laser irradiation on healing of extraction sockets in streptozotocin-induced diabetic rats: a pilot study.

Low-level laser irradiation can promote the healing process in soft and hard tissue but the precise mechanisms are unclear. In this study, we examined the effect of LLLT (low-level laser therapy) on the healing of extraction sockets in diabetic and healthy rats. Forty-eight Sprague-Dawley rats were divided into normal (n = 24) and diabetic (n = 24) rats, and streptozotocin (STZ) injection was used to induce diabetes in the latter. The left and right maxillary first molars of all the rats were extracted. In the non-diabetic rats, the left extraction sockets were not irradiated (group 1) and the right ones were irradiated daily for 3, 5, 7, and 14 days after extraction with a galium-aluminum-arsenide (GaAlAs) diode laser (group 2), and in the diabetic rats, similarly the left ones were not irradiated (group 3) and the right ones were irradiated (group 4). Specimens acquired at these intervals were examined by hematoxylin and eosin (H&E) staining and reverse transcription polymerase chain reaction (RT-PCR). Histological observations and gene expression analyses revealed that groups 2 (normal rats with LLLT) and 4 (diabetic rats with LLLT) showed faster initial healing and more new alveolar bone formation than group 1 (normal rats without LLLT) and group 3 (diabetic rats without LLLT), respectively. We conclude that 980-nm GaAlAs low-intensity diode laser irradiation is beneficial for the initial stages of alveolar bone healing and for further calcification in both diabetic and normal rats when applied every day at a dose of 13.95 J/cm(2) for 60 s.

Effect of low-level laser therapy on the healing process after tooth replantation: a histomorphometrical and immunohistochemical analysis.

Success of tooth replantation is limited because part of the replanted tooth is lost because of progressive root resorption. This study used histomorphometry and immunohistochemistry to evaluate the effect of low-level laser therapy (LLLT) on the healing process of rat teeth replanted after different extra-oral periods, simulating immediate and delayed replantation. Sixty Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and randomly assigned to six groups (n = 10): C4, C30 and C45, in which the teeth were replanted 4 min (immediate), 30 min (delayed) and 45 min (delayed) after extraction, respectively, and L4, L30 and L45, in which the teeth were replanted after the same extra-alveolar times, but the root surfaces and the alveolar wounds were irradiated with a gallium-aluminum-arsenate (GaAlAs) diode laser before replantation. The animals were sacrificed after 60 days. The anatomic pieces containing the replanted teeth were obtained and processed for either histomorphometrical analysis under optical microscopy or immunohistochemical expression of receptor activator of nuclear factor Kappa-B (RANK), and its ligand (RANKL), osteoprotegerin (OPG) and tartrate-resistant acid phosphatase (TRAP) proteins. Areas of external replacement and inflammatory root resorption were observed in all groups, without statistically significant differences (P > 0.05). Ankylosis was more frequent in L30 than in C30 (P < 0.05). RANKL immunostaining predominated over RANK and OPG immunostaining in both groups with immediate tooth replantation (P < 0.05). For the 45-min extra-alveolar time, however, there was greater evidence of RANK immunostaining compared to RANKL for both control and laser-treated groups (P < 0.05). Positive TRAP immunostaining predominated in L4 and L30 (P < 0.05). In conclusion, under the tested conditions, the treatment of the root surface and the alveolar wound with LLLT did not improve the healing process after immediate and delayed tooth replantation in rats.

Influence of carbon dioxide laser irradiation on the healing process of extraction sockets.

OBJECTIVE: To clarify the healing-promoting effects of carbon dioxide laser irradiation in high and low reactive-level laser therapies (HLLT and LLLT, respectively) on extraction sockets after tooth extraction. MATERIAL AND METHODS: Forty-two 5-week-old male Wistar rats were divided into laser irradiation and non-irradiation (control) groups and compared. The laser-irradiation group underwent HLLT immediately after tooth extraction and then LLLT 1 day post-extraction. Tissue was excised 6 h and 3, 7, or 21 days after extraction and histopathologically investigated. The alveolar crest height was measured osteomorphometrically 21 days post-extraction, and granulation tissue in the extraction socket surface layer was immunohistologically investigated using anti-α-smooth muscle actin (anti-α-SMA) antibody 3 and 7 days post-extraction. RESULTS: Many osteoclasts appeared and active bone resorption was noted in the irradiation group 3 days after extraction compared to the controls. On Day 7, new bone formation started around the extraction socket in the control group, but from the superficial to over the middle layer of the socket in the irradiation group. On Day 21, a concavity existed in the alveolar crest region in the controls, whereas this region was flat, with no concavity, in the irradiation group. On osteomorphometry, the alveolar crest height was significantly higher in the irradiation (0.7791 ± 0.0122) than the control (0.6516 ± 0.0181) group (P < 0.05). On immunostaining, many α-SMA-positive cells were noted in the control group, but very few in the irradiation group. CONCLUSION: Laser-irradiated extraction wound healing showed characteristics different from those of the normal healing process, suggesting a favorable healing-promoting effect.

Immediate implant placement into infected sites: bacterial studies of the Hydroacoustic effects of the YSGG laser.

This article describes the use of an erbium laser to use photoacoustics to reduce the bacteria in osteotomy sites that were infected by apical pathology. The author shows reduced bacterial counts by performing bacterial cultures following laser treatment. Swabs were taken after the extraction of the tooth and then after the laser was placed into the osteotomy site. The results showed a noticeable reduction of bacteria and no traces of virulent bacteria.

Incidence and prevention of osteoradionecrosis after dental extraction in irradiated patients: a systematic review.

This systematic review aims to identify and review the best available evidence to answer the clinical question 'What are the incidence and the factors influencing the development of osteoradionecrosis after tooth extraction in irradiated patients?'. A systematic review of published articles on post-irradiation extraction was performed via electronic search of the Medline, Ovid, Embase and Cochrane Library databases. Additional studies were identified by manual reference list search. Evaluation and critical appraisal were done in 3 stages by two independent reviewers and any disagreement was resolved by discussion with a third party. 19 articles were selected for the final analysis. The total incidence of osteoradionecrosis after tooth extraction in irradiated patients was 7%. When extractions were performed in conjunction with prophylactic hyperbaric oxygen, the incidence was 4% while extraction in conjunction with antibiotics gave an incidence of 6%. This systematic review found that while the incidence of osteoradionecrosis after post-irradiation tooth extractions is low, the extraction of mandibular teeth within the radiation field in patients who received a radiation dose higher than 60Gy represents the highest risk of developing osteoradionecrosis. Based on weak evidence, prophylactic hyperbaric oxygen is effective in reducing the risk of developing osteoradionecrosis after post-radiation extractions.