Histological and immunohistochemical soft-tissue response to cylindrical and concave abutments: Multicenter randomized clinical trial.

BACKGROUND: This study aimed to analyze the influence of concave and cylindrical abutments on peri-implant soft tissue. Dimensions, collagen fiber orientation, and immunohistochemical data were assessed. METHODS: A multicenter, split-mouth, double-blind randomized clinical trial was conducted. Two groups were analyzed: cylindrical abutments and concave abutments. After a 12-week healing period, peri-implant soft tissue samples were collected, processed, and evaluated for dimensions, collagen fiber orientation, and immunohistochemical data. Inflammatory infiltration and vascularization were assessed, and the abutment surfaces were analyzed using scanning electron microscopy. The statistical analysis was performed using the SPSS version 20.0 statistical package. RESULTS: A total of 74 samples in 37 patients were evaluated. Histological evaluation of peri-implant soft tissue dimensions revealed significant differences between concave and cylindrical abutments. Concave abutments exhibited greater total height (concave: 3.57 ± 0.28 - cylindrical: 2.95 ± 0.27) and barrier epithelium extension (concave: 2.46 ± 0.17 - cylindrical: 1.89 ± 0.21) (p < 0.05), while the supracrestal connective tissue extension (concave: 1.11 ± 0.17 - cylindrical: 1.03 ± 0.16) was slightly greater (p > 0.05). Collagen fiber orientation favored concave abutments (23.76 ± 5.86), with significantly more transverse/perpendicular fibers than for cylindrical abutments (15.68 ± 4.57). The immunohistochemical analysis evidenced greater inflammatory and vascular intensity in the lower portion for both abutments, though concave abutments showed lower overall intensity (concave: 1.05 ± 0.78 - cylindrical: 1.97 ± 0.68) (p < 0.05). The abutment surface analysis demonstrated a higher percentage of tissue remnants on concave abutments (42.47 ± 1.32; 45.12 ± 3.03) (p < 0.05). CONCLUSIONS: Within the limitations of this study, concave abutments presented significantly greater peri-implant tissue height, linked to an extended barrier epithelium, versus cylindrical abutments in thick tissue phenotype. This enhanced soft tissue sealing, favoring a greater percentage of transversely oriented collagen fibers. The concave design reduced chronic inflammatory exudation with T and B cells, thus minimizing the risk of chronic inflammation. PLAIN LANGUAGE SUMMARY: This study looked at how 2 different shapes of dental implant abutments (the parts that connect the implant to the crown), specifically concave and cylindrical, affect the soft tissue around the implants. We wanted to see how these shapes influenced the tissue's size, structure, and health. We conducted a clinical trial with 37 patients, comparing the 2 types of abutments in the same mouth over 12 weeks. Our findings showed that the concave abutments led to a taller and more extensive layer of protective tissue around the implant compared to the cylindrical ones. This protective tissue had more favorable collagen fiber orientation, which is important for the strength and health of the tissue. Additionally, the concave abutments resulted in less inflammation and better tissue integration. In conclusion, concave abutments may provide better support and health for the soft tissue around dental implants, reducing the risk of chronic inflammation and potentially leading to better long-term outcomes for patients with dental implants.

Randomized split-mouth clinical trial comparing osteoblastic activity and osteogenic potential of autogenous particle harvesting during implant surgery without irrigation and with irrigation.

OBJECTIVE: To compare the osteoblastic activity and osteogenic potential of autogenous particle harvesting during implant surgery using low-speed drilling without irrigation and high-speed drilling with irrigation. MATERIALS AND METHODS: Thirty patients with bilateral missing teeth of 3.6 and 4.6 were randomized into two groups (Group 1: low-speed drilling without irrigation and Group 2: high-speed drilling with irrigation) and 60 single dental implants were placed. The temperature at the tip of each drill was recorded and the harvested bone was weighed; particle size and Ca and P levels were also analyzed. After osteoblast culture, cell viability, cell cycle assay, cell migration, vascular endothelial growth factor (VEGF) concentration, and mineralized nodule formation were assessed. RESULTS: Although the temperature of the drills was slightly higher in Group 1, no statistically significant differences were observed (p ≤ 0.05); however, the amount of harvested bone was higher (p < 0.001) and the size of the particles was higher (p = 0.019). In relation to osteoblastic activity and osteogenic potential, higher cell proliferation, higher number of cells in G2/M and S phases, higher cell migration capacity, higher VEGF concentration, and higher amount of mineralized nodule formation were observed in Group 1. CONCLUSIONS: Low-speed drilling without irrigation does not result in a significant increase in bone temperature compared to conventional drilling. However, a greater amount of bone is obtained; in addition, osteoblastic activity and osteogenic potential are higher with this technique, but further clinical studies are necessary.

Autologous bone harvested during implant bed preparation: A randomized clinical trial comparing high-speed drilling with irrigation versus low-speed drilling without irrigation.

OBJECTIVE: To compare collected bone weight and the frequency of autologous bone harvesting from the flutes of surgical drills used for implant bed preparation using two different drilling techniques. A comparative evaluation of radiographic bone density and bone quality was also made. MATERIALS AND METHODS: A randomized clinical trial was made of 66 dental implants in patients with a single posterior edentulous site. The compared drilling techniques were high-speed drilling with irrigation (control group) and low-speed drilling without irrigation (test group). The bone collected in both groups was dried and weighed with a precise electronic balance. The frequency of harvesting was calculated. The median radiographic bone density of each implant site was measured using cone-beam computed tomography (CBCT) pixel values. Patient sex, age, implant position and dimensions, as well as the last drill diameter were analyzed as independent variables. The level of significance was 5%. RESULTS: The harvesting of bone chips from drill flutes proved possible in 51.5% of the procedures in the control group and in 100% in the test group (p < 0.001). There were also statistically significant differences in bone weight between the control group (6.7 ± 10.6 mg) and the test group (41.9 ± 30.3 mg) (p < 0.001). The CBCT pixel values were directly correlated with the collected bone weight in both groups. The median radiographic bone density, arch and last drill diameter were significantly associated with harvesting bone frequency and collected bone weight (p < 0.05). CONCLUSIONS: Our findings suggest that the frequency and weight of autologous bone harvested from drills are greater with low-speed drilling without irrigation than with high-speed drilling with irrigation. Radiographic bone density, arch and last drill diameter also significantly influenced the harvesting outcomes.

Comparison of patient-centered outcomes measures between low-speed drilling without irrigation and high-speed drilling with irrigation: A randomized clinical trial.

OBJECTIVE: To compare patient satisfaction during surgery, postoperative pain and inflammation and quality of life between high-speed drilling with irrigation and low-speed drilling without irrigation for implant bed preparation. MATERIALS AND METHODS: Sixty-six posterior single edentulous patients were included in a randomized controlled clinical trial. Implant beds were created using high-speed drilling with irrigation (control group) or low-speed drilling without irrigation (test group). Patient satisfaction during surgery (in relation to drilling-time perception, vibration, pressure, noise, comfort, and drowning sensation) and postoperative pain and inflammation were evaluated using a 100-mm visual analogue scale (VAS)-based questionnaire. Quality of life was analyzed with a Likert scale (in relation to mouth opening, chewing, speaking, sleeping, daily routine, and job). The follow-up period was 7 days. RESULTS: Patient satisfaction in relation to drilling-time perception, vibration, pressure, and noise did not show statistically significant differences (p > .05). The highest scores of drowning sensation (p < .05) were correlated (moderate correlation (r = .57)) with lowest scores of comfort (p < .005). Both postoperative pain and inflammation means were significantly higher in the control group than in the test group. No significant differences in quality of life were observed during the postoperative period (p > .05). CONCLUSION: Low-speed drilling without irrigation for single implant site preparation was more comfortable for patients than high-speed drilling with irrigation, due to the correlation between important drowning sensation and low perceived comfort. Postoperative pain and inflammation were lower for low-speed drilling without irrigation. Further studies are needed to validate or refute these results.

Evaluation of Change in Radiographic Fractal Dimension around Dental Implants Placed with Low-Speed Drilling and Standard Drilling Protocols.

Osseointegration is a process that depends on a multitude of factors, including the type of drilling, whether biological or conventional. OBJECTIVE: Establish box-counting dimension values for radiological images in patients with implants placed with both drilling methods. MATERIAL AND METHOD: The sample included 129 implants corresponding to 50 patients. A double-blind study of data collection was carried out with the subsequent analysis of the fractal dimension as a comparative value of the state of the trabecular architecture. RESULTS: We found no significant differences (p ≥ 0.05) between the two study groups comparing both drilling techniques. The values for the conventional drilling technique are 0.24 ± 0.07 and for biological drilling: 0.19 ± 0.11 with a p-value of 0.767. CONCLUSIONS: The drilling technique does not influence the success of the procedure and the osseointegration process.

Regeneration of periodontal bone defects with mesenchymal stem cells in animal models. Systematic review and meta-analysis.

The aim of this study was to evaluate the efficacy of mesenchymal stem cells (MSCs) in the regeneration of periodontal bone defects in animal models. A systematic review and meta-analysis were conducted following the PRISMA guidelines, and the study was recorded in PROSPERO under reference number CDR42021247462. The PICO question was: is periodontal regeneration (cementum, periodontal ligament and alveolar bone) with MSCs more effective than other techniques? Three groups were considered: Group 1: MSCs alone or mixed with regenerative materials. Group 2: only regenerative materials. Group 3: no regenerative material nor MSCs. The search was conducted using MeSH with a total of 18 articles for qualitative analysis and 5 for quantitative analysis. For the meta-analysis, a modification of the effect size algorithm was developed, which considered a comparison of means between treatments using the Student's t sample distribution. When comparing the effect size between Group 1 and Group 2, the effect size for the new cementum was 2.83 mm with an estimated confidence interval of 95% (CI 95%) between 0.48 and 5.17 mm. When considering the fit to a random-effects model, the combined variance (τ2) was 6.1573 mm, with a standard deviation (SD) of 5.6008 mm and a percentage of total heterogeneity I2 of 92.33% (p < 0.0001). For new bone, the effect size was 0.88 mm, CI 95% - 0.25 to 2.01 mm, τ2 = 1.3108 mm (SD = 1.2021 mm) and I2 = 80.46%, p = 0.0004). With regard to the new periodontal ligament, it was not possible for the meta-analysis to be performed. MSCs have a greater capacity for tissue regeneration in root cementum than in alveolar bone compared to other regenerative materials.

Photobiomodulation in dental implant stability and post-surgical healing and inflammation. A randomised double-blind study.

BACKGROUND: The aim of this randomized clinical trial was to evaluate the effect of diode laser photobiomodulation (PBM) on post-surgical healing, inflammation and implant stability. METHODS: Forty dental implants were inserted into 13 patients. The implants were randomly divided into two groups. The test group (PBM+) underwent two sessions of PBM (combined diode laser of 630 and 808 nm), the first of which after surgery, and the second, 7 days after the surgical procedure. The control group (PBM-) received simulated laser treatment. The implant stability quotient (ISQ) was determined immediately after the surgical procedure, and 7 days, 4 and 8 weeks later. Post-surgical inflammation was assessed following the criteria described by Bloemen and Cols. Healing was calculated using the healing index (HI). RESULTS: No differences were found in terms of the mean values of implant stability between the test and control groups over time. Only two of the implants (18.2%) from the PBM- group were classified with the maximum healing index (HI = 5), whereas in the PBM+ group, nine implants (45%) were classified with the aforementioned index (P < 0.0001). Using the logistic regression, it was determined that the non-application of the laser in the PBM- group caused an OR of 4.333 times of presenting inflammation (IC95% 1.150-16.323; P = 0.030). CONCLUSIONS: The application of 808 nm infra-red laser for bone tissue, and 630 nm for mucosal tissue in two sessions is considered to be an effective way of reducing inflammation and improving early healing. More studies are needed to confirm these results.

In vitro bacteriological effect of tri-beveled needle electrolysis against Staphylococcus aureus.

Percutaneous needle electrolysis using tri-beveled needles with a specific protocol (5 mA applied for 25 s) has demonstrated to provoke a clinical reduction of recurrent bacterial infections in mammary fistulas. However, the bactericidal effect of needle electrolysis in this pathology remains theoretical. This in vitro study evaluated the bactericidal effect of this protocol and whether it changed when introducing small variations. Staphylococcus aureus were generated in saline solution (9 Log10 CFU/mL) and treated in three different experiments including the main protocol and introducing variations in needle gauge, intensity, and total dosage, respectively. After 24 h, the viable cell count showed that the protocol had an average reduction of 5 log10 CFU/ml compared to the control group. While variations in needle gauge did not modify this effect, variations in current intensity or dosage did. This study demonstrated that the bacterial effect was greater by increasing either current intensity or total dosage, and it decreased with substantial reductions of these parameters.

Study of the Effect of Photobiomodulation on a Skin Repair Model in SKH-1 Mice.

Background and objective: Laser applied at low power (400-1100 nm), currently named photobiomodulation (PBM), is a noninvasive therapy to speed up wound healing. The purpose of this study was whether two different laser PBM delivery protocols would impact the skin wound healing in a mouse model. Materials and methods: A total of 24 SKH-1 mice were divided into three groups: Group 1 (control: untreated ulcers), Group 2 (a single postsurgical laser application), and Group 3 (laser each other day for 10 days; total five applications). Laser parameters were 940 nm, 0.4 W, 10 mm spot size, 0.008 J/cm2, 300 sec/wound. Each animal received two skin wounds which were photographed on days 0, 5, and 10 to determine wound closure (ImageJ). Half of the animals in each group were sacrificed on day 5 and the other half on day 10. Samples were routinely processed for histological analysis (re-epithelization, angiogenesis, granulation tissue formation, inflammation, and collagen deposition). Results: The closure of the wounds at the end of the experiment in the animals photobiostimulated each other day was more advanced than in the controls and in those treated only once, in both the macroscopic and microscopic studies. Angiogenesis was higher in both treated groups than in the control in the first study time (day 5). However, inflammation, maturation of the granulation tissue, and collagen deposition only improved when the laser was applied each other day. Conclusions: In our study, with the parameters used, PBM improved the healing of skin wounds when applied every other day and not in a single dose.

Use of buccal fat pad-derived stem cells cultured on bioceramics for repair of critical-sized mandibular defects in healthy and osteoporotic rats.

OBJECTIVE: To compare new bone formation in mandibular symphysis critical-sized bone defects (CSBDs) in healthy and osteoporotic rats filled with bioceramics (BCs) with or without buccal fat pad mesenchymal stem cells (BFPSCs). MATERIALS AND METHODS: Thirty-two adult female Sprague-Dawley rats were randomized to two groups (n = 16 per group): group 1 healthy and group 2 osteoporotic (with bilateral ovariectomy). The central portion of the rat mandibular symphysis was used as a physiological CSBD. In each group, eight defects were filled with BC (hydroxyapatite 60% and ß-tricalcium phosphate 40%) alone and eight with BFPSCs cultured on BC. The animals were sacrificed at 4 and 8 weeks, and the mandibles were processed for micro-computed tomography to analyze radiological union and bone mineral density (BMD); histological analysis of the bone union; and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2). RESULTS: In both groups, CSBDs filled with BC + BFPSCs showed greater radiological bone union, BMD and histological bone union, and more VEGF and BMP-2 positivity, compared with CSBDs treated with BC alone at 4 and 8 weeks. CONCLUSIONS: The application of BFPSCs cultured on BCs improves bone regeneration in CSBDs compared with BCs alone in healthy and osteoporotic rats. CLINICAL RELEVANCE: Our results may aid bone regeneration of maxillofacial CSBDs of both healthy and osteoporotic patients, but further studies are necessary.

Properties of polyetheretheretherketone (PEEK) implant abutments: A systematic review.

Background: The main objective of the present systematic review is to know the mechanical and functional properties of PEEK (polyetheretheretherketone) abutment and to find out if it is a potential substitute for titanium abutments. Material and Methods: An electronic search was conducted in 5 databases: Medline (Pubmed), SciELO, Cochrane, Web of Science (WOS) and Google Scholar. Studies published from 2018 to 2020 and written in English were included. The protocol of this systematic review was registered in PROSPERO (ID 274834). Subsequently, data extraction and quality analysis were performed according to the modified CONSORT guidelines. Results: Initially, a total of 976 articles were obtained. Using Mendeley Desktop, duplicates were discarded, reducing the number of articles to 483. After reading abstracts, 448 articles were excluded. Finally, 35 full-text articles were analysed, of which 5 articles were included in this systematic review. Conclusions: The available evidence shows that PEEK implant abutments do not have sufficient biomechanical requirements to replace the definitive titanium abutment. However, it is considered as an alternative and provisional material, especially if placed in the anterior region. Key words:Abutment, polyetheretheretherketone, titanium, dynamic fatigue, fracture toughness, loss of torque.

Synergistic antimicrobial effect of photodynamic therapy and chitosan on the titanium-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa: An in vitro study.

BACKGROUND: To date, no studies on the combined use of photodynamic therapy (PDT) and chitosan against peri-implantitis have been published. The aim of this study was to evaluate the possible synergistic antimicrobial effect of PDT and chitosan on the titanium-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. METHODS: A total of 60 titanium discs were included in this study. The discs were randomized into three bacterial contaminations (n = 20 discs per bacterium). After being cultured (incubated for 48 hours) they were randomized again into four different disinfection modalities (n = 5 discs per treatment): control (without treatment), PDT, chitosan 3 mg/mL, and PDT + chitosan 3 mg/mL. After the treatments, the colony forming units (CFU) were measured to determine antimicrobial effects, and field emission scanning electron microscopy (FESEM) was used to study cell morphology and titanium adherence. RESULTS: For all the evaluated bacteria and all the variables studied the order from highest to lowest antimicrobial effectiveness was: PDT + chitosan 3 mg/mL > chitosan 3 mg/mL > PDT > control. Although, all disinfection methods were significantly effective when compared to control, the combined treatment of PDT + chitosan 3 mg/mL had the greatest antimicrobial effect against the three studied bacteria. CONCLUSIONS: The combination of PDT and chitosan has a synergistic antimicrobial effect against the bacteria S. aureus, E. coli, and P. aeruginosa, all closely related to peri-implantitis. However, further in vivo studies are needed because this study provides data based on an in vitro scenario that might not be extrapolated to patients with peri-implantitis.

Short Dental Implants (≤8.5 mm) versus Standard Dental Implants (≥10 mm): A One-Year Post-Loading Prospective Observational Study.

BACKGROUND: Recent data have shown that short dental implants can be the preferred treatment in most of cases of posterior atrophic alveolar ridges, offering higher survival and lower complication rates than long implants. The survival rates, stability, and marginal bone level changes were compared between short implants (7 and 8.5 mm) and standard-length implants (≥10 mm). METHODS: Prospective observational study in which adult patients requiring ≥1 osseointegrated implants to replace missing teeth were recruited consecutively. A clinical examination was performed on the day the definitive prosthesis was placed and after 6 and 12 months. Implant stability quotient (ISQ), marginal bone level (MBL) changes, and the correlation between these parameters and the characteristics of the implants were evaluated. RESULTS: A total of 99 implants were inserted (47 short, 52 standard) in 74 patients. The 12-month survival rate was 100%. ISQ values showed a similar pattern for both types of implants. No correlation was found between ISQ changes after one year and MBL values, nor between the latter and the characteristics of the implants. CONCLUSIONS: With clinical treatment criteria, shorter implants (7 and 8.5 mm in length) can be just as useful as standard-length implants in atrophic alveolar ridges, demonstrating similar rates of survival, stability, and crestal bone loss.

Evaluation of Quality of Life and Satisfaction in Patients with Fixed Prostheses on Zygomatic Implants Compared with the All-on-Four Concept: A Prospective Randomized Clinical Study.

Purpose: No published research has compared patients' quality of life and satisfaction with fixed prostheses supported by zygomatic implants with those supported by all-on-four prostheses. The aim of this study was to evaluate patients' quality of life and satisfaction with fixed prostheses on zygomatic implants compared with the all-on-four concept. Materials and Methods: A total of 80 patients with atrophic edentulous maxillae were randomized into two groups: Group 1 (rehabilitated with fixed prostheses supported by 2-4 zygomatic and 2-4 conventional implants in the anterior region) and Group 2 (fixed prostheses on four implants in the anterior region following an all-on-four concept). One year after placement of the definitive prostheses, patients completed OHIP-14 and satisfaction questionnaires. Results: In all seven domains of the OHIP-14 and in the overall scores, a worse quality of life was found in Group 2 patients, with statistically significant differences between the two groups (p ≤ 0.05). Patients with zygomatic implants were more satisfied with their prostheses, with a statistically significant difference (p < 0.001). Conclusions: According to the results of this study, rehabilitation of patients with edentulous atrophic maxillae with prostheses supported by zygomatic implants combined with anterior implants provided better patient quality of life and satisfaction than prostheses supported by four implants.

Low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation: a systematic review.

PURPOSE: This paper aims to review the evidence comparing low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation. MATERIALS AND METHODS: A systematic review was carried out based on the PRISMA statement. Four databases and gray literature were searched up to November 2020. In vitro, animal, and clinical studies were included. The variables were temperature change, drilling time, quantity of harvested bone, osteotomy precision, marginal bone loss, implant success rate, osseointegration, and the histomorphologic characteristics and cellularity of the osteotomy and of the harvested bone. Different tools for the assessment of bias were applied for each study design. RESULTS: A total of 626 articles were identified, of which 13 were included. Both low-speed drilling without irrigation (test group) and conventional drilling (control group) maintained temperatures below the critical temperature of 47 °C. The test group yielded a greater quantity and more beneficial cellular and histomorphologic properties of harvested bone, with a longer drilling time and greater osteotomy precision (p < 0.05). No significant results were obtained regarding drill wear, osseointegration, marginal bone loss, implant success rate, and histomorphology of the dental implant osteotomy (p > 0.05). The results, in particular on the osteotomy precision and quantity of harvested bone chips, should be interpreted with caution because outcomes are based in only one in vitro study. CONCLUSIONS: Low-speed drilling without irrigation seems to be comparable to conventional drilling in preparing dental implant osteotomies. In some situations, low-speed drilling without irrigation might offer advantages over conventional drilling. The results should be interpreted with caution due to the low percentage of clinical human studies. Accordingly, more clinical studies are needed to improve the scientific evidence on this topic. CLINICAL RELEVANCE: The low-speed drilling without irrigation is a valid technique for dental implant osteotomy preparation. Its higher quantity and quality of harvested autologous bone might be particularly beneficial in cases of dental implant placement with minor simultaneous bone regeneration.

The quality of Internet information relating to 2019-nCov transmission control in dental practice.

BACKGROUND: To date, the quality of the Internet information regarding the control and management of 2019-nCov virus transmission in dental clinics has not been evaluated. The aim of this study was to evaluate the quality of Internet information about the control of 2019-nCov transmission in dental practice. MATERIAL AND METHODS: Internet websites were identified daily using two search engines: Google and Yahoo! during the week from 20-06-2020 to 26-06-2020, applying the search term "2019-nCov transmission control in dental practice." The first 100 consecutive sites identified in each search were visited and classified. The quality of information contained in each website was analyzed using the Journal of the American Medical Association (JAMA) benchmarks, whether the website had been granted the Health on the Net Foundation Code of Conduct (HONcode), and a new tool for evaluating the quality of Internet websites providing information relating to 2019-nCov transmission control in dental practice, which awards a score of 0-40 points (8-13: poor; 14-26: medium; and 27-40 high). RESULTS: After the exclusion of duplicates, non-functioning websites, books/journals, irrelevant websites, or websites not in English, a total of 30 websites were evaluated. Only 6.66% fulfilled all four JAMA benchmarks, none had been granted the HONcode, and only 10% presented high quality information. CONCLUSIONS: The quality of Internet information about 2019-nCov transmission control in dental practice is poor. This study points to the need to improve the quality of information available on the Internet relating to 2019-nCov transmission control in dental practice. Key words:2019-nCov, COVID-19, transmission control in dental practice, Internet, quality of information.

Regeneration of lingual musculature in rats using myoblasts over porcine bladder acellular matrix.

OBJECTIVES: To use tissue engineering muscle repair (TEMR) for regenerating the lingual musculature of hemiglossectomized rats using neonatal myoblasts (NM) on porcine acellular urinary bladder matrix (AUBM). MATERIAL AND METHODS: The study used 80 male rats. A volumetric muscle loss (VML) injury was created on the left side of the tongue. The rats were randomized into four groups: Group 1 (AUBM + myoblasts); Group 2 (AUBM); Group 3 (myoblasts); and Group 4 (control). NM were obtained from neonatal rats. The animals were weighed on day 0 and just before euthanasia. Five rats in each group were euthanized at days 2, 14, 28, and 42; the tongues were prepared for morphometric analysis, postoperative left hemitongue weight, and immunohistochemical analysis (desmin, CD-31, and anti-neurofilament). RESULTS: The weight gain from greatest to least was as follows: AUBM + myoblasts > myoblasts > AUBM > control. The tongue dorsum occupied by VML, and difference in mg between control side and intervened side from least to great was as follows: AUBM + myoblasts < myoblasts < AUBM < control. The order from highest to lowest antibody positivity was as follows: AUBM + myoblasts > myoblasts > AUBM > control. CONCLUSION: The use of porcine AUBM and NM for the regeneration of lingual musculature was found to be an effective TEMR treatment for repairing tongue VML injury.

In Vitro Study of Synergic Effect of Cisplatin and Low Molecular Weight Heparin on Oral Squamous Cell Carcinoma.

OBJECTIVES: To evaluate the possible synergic effect of cisplatin and low molecular weight heparin (LMWH) on oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Cisplatin and enoxaparin sodium, alone or in combination, were administered at doses of 1, 2, 4, 8 and 10 µM and 0.1, 0.5, 1, 5, 10, 50, and 100 µg/ml, respectively, to the H357 human OSCC line. The effects on cell viability and apoptosis were evaluated after 24, 48, and 72 h and on cell migration after 18 and 24 h. RESULTS: 10 µM concentration of cisplatin produced the greatest decrease in cell viability, with significant differences at 24 (p=0.009), 48 (p=0.001) and 72 h (p = 0.003); the 100 µg/ml dose of enoxaparin produced the greatest decrease in cell viability but without significant differences (p>0.05). When different concentrations of cisplatin and enoxaparin were combined, it was found that 100 µg/ml enoxaparin sodium produced the greatest synergic effect on cell viability reduction. In analyses of apoptosis and cell migration, it was found that the combination of cisplatin at 8 or 10 µM and 100 µg/ml enoxaparin produced a higher rate of apoptosis at 24, 48, and 72 h and a greater reduction in cell migration at 18 and 24 h. CONCLUSIONS: A combination of cisplatin and enoxaparin sodium shows a synergic effect that reduces cell viability and cell migration capacity and increases the apoptosis of human OSCC cells. CLINICAL RELEVANCE: Enoxaparin may be beneficial in chemotherapy for patients with OSCC; this finding requires further clinical and laboratory investigation.

Genotype of Null Polymorphisms in Genes GSTM1, GSTT1, CYP1A1, and CYP1A1*2A (rs4646903 T>C)/CYP1A1*2C (rs1048943 A>G) in Patients with Larynx Cancer in Southeast Spain.

BACKGROUND: some types of cancer have been associated with the presence of single nucleotide polymorphisms (SNPs) of some genes that encode enzymes: glutathione-S transferase (GST), whose alteration leads to loss of function and a lower capacity to eliminate toxic GSTM1 and GSTT1 null genotypes; SNPs causing loss of function of CYP1A1 or CYP1A1-2 cytochrome P450 enzymes related with a lower capacity to deactivate hydrocarbons related to smoking, which involves a higher risk of developing some smoking-dependent cancers including larynx cancer. OBJECTIVE: to compare the presence of null SNPs in genes GSTM1, GSTT1, and CYP1A1 rs 4646903 T>C, and CYP1A1-2 RS1048943 A>G in patients with hypopharyngeal and larynx cancer with a healthy control group. MATERIALS AND METHOD: The study included a total of 80 patients with hypopharyngeal and laryngeal cancer and 23 healthy subjects. Genomic DNA was obtained from saliva samples, determining genotype GSTM1 (present +, or null -), GSTT1 (present + or null -). Polymorphisms (SNP) in CYP1A1 T>C (present + CC, or absent - TC/TT), and CYP1A1-2 A>G (present + GG, or absent - AG/AA). RESULTS: the mean age of patients with larynx cancer was 62 years and of control subjects 63 years. Of the total sample, over 95% were men, and over 90% were smokers. The presence of null genotypes for GTM1 was 50% in patients with larynx cancer (p = 0.042), while GSTT1 was 88.75% (p = 0.002). CYP1A1 rs4646903 T>C polymorphisms were detected in 100% of cases of larynx cancer and 17.39% of healthy subjects (p > 0.001). CONCLUSIONS: patients with larynx cancer present more gene GSTM1 and GSTT1 null polymorphisms, and CYP1A1 rs4646903 T>C polymorphisms.

Chemopreventive effect of pomegranate and cocoa extracts on ultraviolet radiation-induced photocarcinogenesis in SKH-1 mice.

Non-melanoma skin cancer (NMSC) has a high and increasing incidence all over the world. Solar radiation is the main aetiology for humans. Although most research into photocarcinogenesis uses UVB as a source of radiation, UVA is also carcinogenic in long term. Pomegranate (PGE) and cocoa (CE) extracts have been used for medicinal purposes for time immemorial. Recently, it has been claimed that some of their properties may be an effective preventative measure against photocarcinogenesis and photoaging, but to date in vivo models have not been tested using RUVA, the objective of the present work. A lower incidence of lesions was observed in SKH-1 mice treated with PGE (p<0.001), and lower incidence of invasive squamous carcinoma in both treatment groups (p<0.001 for PGE and p<0.05 for CE); the PGE group also showed a lower level of cell proliferation than the control group (p<0.001). Significantly greater p53 alteration was observed in the control group than the treatment groups (p<0.001 for PGE and p = 0.05 for CE). No significant differences were found in relation to TIMP-1 and MMP-9. Taken together, the results suggest that oral feeding of PGE and CE to SKH-1 mice affords substantial protection against the adverse effects of RUVA, especially PGE.