Modified one-stage technique of laterally positioned flap with subepithelial connective tissue graft for the treatment of peri-implant soft tissue dehiscence in the esthetic zone: A 5-year follow-up.

BACKGROUND: The state of art of tissue grafting allows significant improvements in the soft tissue phenotype. The importance of appropriate soft tissue phenotype around implants is supported by recent literature. The present case report aims to describe the application of a modified one-stage technique of laterally positioned flap with subepithelial connective tissue graft (CTG) for the treatment of peri-implant soft tissue dehiscence in the esthetic zone. METHODS AND RESULTS: A 38-year-old female presented 4 years following prosthetic restoration, with a localized soft tissue defect in height and thickness at the buccal aspect of the implant at #11, and the abutment exposed to the oral cavity. Incisions with internal and external bevels were performed in the medial and distal margins of the dehiscence, respectively, toward the alveolar mucosa. After intrasulcular incision, the area was de-epithelialized and a split thickness flap from mesial #11 to distal #14 was elevated. A tunnel was prepared at #21. CTG was stabilized mesially, within the tunnel prepared, and distally, through simple interrupted sutures. Vertical compressive sutures were performed on the CTG. The flap was laterally positioned and secured by means of suspended sutures. Healing was uneventful, increased thickness and height of the peri-implant mucosa were observed, with great esthetic outcome. The soft tissue margin was stable at the 5-year follow-up. CONCLUSION: The technique described in this case report showed promising results for covering exposed implant abutment in the esthetic zone, as well as for modification of the soft tissue phenotype around dental implants. KEY POINTS: Why is this case new information A modified one-stage technique that allows coverage of exposed metallic displays of titanium implants while modifying the soft tissue phenotype in the esthetic zone. What are the keys to successful management of this case? Meticulous incisions and internal and external bevels. Adequate elevation to allow repositioning without tension. Adequate graft size that extends through all the recipient bed; and tension-free suture. What are the primary limitations to success in this case? Presence of an implant installed in a non-satisfactory three-dimensional position. And poor hygiene and plaque accumulation postoperatively.

Sodium alendronate is an effective adjunctive therapy for treating periodontitis in male rats treated with anticancer chemotherapy.

OBJECTIVES: To assess sodium alendronate as a local adjunctive therapy for treating experimental periodontitis in male rats treated with chemotherapy. DESIGN: One-hundred-eighty male rats were randomly divided into two groups (n = 90) based on the systemic treatments: PSS, physiological saline solution; and 5-Fluorouracil, and then, subdivided into three subgroups (n = 30): NT, no treatment; scaling and root planing; and sodium alendronate. Treatments were performed 7 days after induction of experimental periodontitis. Specimens were collected at 14, 22, and 37 days after induction. Alveolar bone level, percentage of bone in the furcation, percentage of non-vital bone in the furcation, histopathologic features, and immunolabeling pattern for tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) were evaluated. RESULTS: The lowest amount of alveolar bone and highest amount of non-vital bone was found in group 5-Fluorouracil when no treatment was performed. In animals receiving 5-Flurouracil and subjected to periodontal treatment, adjunctive sodium alendronate resulted in higher percentage of bone in the furcation and higher alveolar bone loss, when compared with scaling and root planing alone. Better structural and cellularity patterns were found in the periodontal tissues when sodium alendronate was used, regardless of systemic treatment. Higher TRAP-expression was found when no treatment was performed. Sodium alendronate didn't affect the immunolabeling pattern of osteocalcin in the presence of 5-Fluorouracil. CONCLUSION: Adjunctive therapy with local sodium alendronate prevented alveolar bone loss and improved the histopathological features of the periodontal tissues following scaling and root planing in male rats with experimental periodontitis receiving anticancer chemotherapy with 5-Fluorouracil.

Hand instrumentation provides improved tissue response over ultrasonic scaler and substantiates safe dental practice: An in vivo study in rats.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of hand debridement (HD) versus ultrasonic dental scaler (UDS) for the treatment of experimental periodontitis (EP) in rats. MATERIAL AND METHODS: Thirty 3-month-old male rats were used. EP was induced around the mandibular first molars (right and left). Seven days after induction, the treatments with either HD (n = 30) or UDS (n = 30) were randomly performed in each molar. Euthanasia were performed at 7, 15, and 30 days after treatment. Histometric (percentage of bone in the furcation [PBF]), histopathological, and immunohistochemical (for detection of tartrate-resistant acid phosphatase [TRAP] and osteocalcin [OCN]). Parametric data (PBF and TRAP) was analyzed by One-way ANOVA followed by Tukey's post-test. OCN was analyzed by Kruskal-Wallis followed by Student-Newman-Keuls post-test. The level of significance was 5%. RESULTS: Group HD presented higher PBF and lower TRAP-immunolabeling at 30 days as compared with UDS in the same period (p≤0.05). Group HD presented higher OCN immunolabeling at 30 days as compared with 7 and 15 days (p≤0.05). Persistent and exacerbated inflammatory process was observed in some specimens from group UDS at 30 days, as well as the bone trabeculae presented irregular contour, surrounded by many active osteoclasts. CONCLUSION: Nonsurgical periodontal therapy with HD resulted in higher PBF and lower expression of TRAP as compared with UDS. Also, HD increased the expression of OCN over time.

Dose-dependent effects of zoledronic acid on the osteogenic differentiation of human bone marrow stem cells (hBMSCs).

Recent studies have shown that bisphosphonates can also impact osteoblasts besides osteoclasts. This study aimed to evaluate the effects of different concentrations of Zoledronic acid (ZA) during the osteogenic differentiation of human Bone Marrow Stem Cells (hBMSCs) in vitro. Thus, osteogenic differentiation of hBMSCs was conducted with different concentrations of Zoledronic Acid (ZA) (0, 0.1, 1.0, and 5.0 µM) for the first 3 days. Cell metabolism was quantified at 1-, 3-, 7-, and 14 days. At 7- and 14-days, the following analyses were performed: 1) mineralization nodule assay, 2) LIVE/DEAD™, 3) cell adhesion and spreading, 4) alkaline phosphatase (ALP) activity, and 5) qPCR analysis for RUNX-2), ALPL, and COL1 A1. Data were analyzed by ANOVA 2-way, followed by Tukey's post hoc test (p < 0.05). Cell metabolism (3-, 7-, and 14-days) (p < 0.001), mineralization (7-, 14-days) (p < 0.001), and ALP activity (14-days) (p < 0.001) were reduced in ZA 5.0 µM when compared to control (no ZA). Also, ZA 5.0 µM downregulated the expression of RUNX2 at 7- and 14-days (p < 0.001). It is possible to conclude that ZA (5.0 µM) can impair hBMSC differentiation into osteoblasts and interferes with its mineralization phase.

Tamoxifen improves homeostasis in the peri-implant bone remodeling of osseointegrated titanium implants.

BACKGROUND: The purpose of this preclinical study was to evaluate the influence of tamoxifen (TAM) on the peri-implant bone remodeling of osseointegrated titanium implants in ovariectomized female rats. MATERIALS AND METHODS: Seventy-two female rats underwent bilateral ovariectomy 20 weeks before implants placement. One titanium implant was inserted in each tibia of the animals. Six weeks following the implant surgery, animals were randomly divided into two experimental groups (n = 36), which received either saline solution (SS) or tamoxifen citrate (TAM) via gavage until euthanasia. Euthanasia was performed at 30, 60, and 90 days after the first gavage. Assessments of bone to implant contact (BIC), bone ingrowth percentage (BIN), morphological description of cellular and tissue reactions, immunohistochemistry for the detection of bone morphogenetic protein 2/4 (BMP2/4), runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP), and bone chemical composition through scanning electron microscopy with energy-dispersive x-ray spectroscopy were performed. RESULTS: Tamoxifen group presented higher BIC, higher BIN, higher RUNX-2 and OCN, lower TRAP-positive cells/mm2 , and no differences regarding BMP-2/4 positive cells/mm2 than SS group in all periods. TAM group also showed higher Ca/P rate than SS group. CONCLUSION: Tamoxifen enhanced the remodeling of the bone surrounding titanium implants in ovariectomized rats.

A new multiphase calcium phosphate graft material improves bone healing-An in vitro and in vivo analysis.

This study aims to evaluate the potential of a novel biomaterial synthesized from amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), and hydroxyapatite (HA) to repair critical-sized defects (CSD) in rabbit calvaria. In vitro analyses of cell viability, cell proliferation, formation of mineral nodules, and cell differentiation using qPCR were performed for comparing experimental calcium phosphate (ECP), deproteinized bovine bone (DBB), and beta-tricalcium phosphate (ß-TCP). Bilateral CSDs were created in 45 rabbit calvaria. Six groups were evaluated: ECP, ECP + fibrin sealant (ECP + S), coagulum, autogenous bone, DBB, and ß-TCP. Euthanasia was performed at 2, 4, and 8 weeks, followed by micro-computed tomography and histological and immunohistochemical analyses. Results from in vitro analyses revealed similar biocompatibility for all tested materials and a tendency for higher gene expression of some bone markers in the ECP group than in ß-TCP and DBB groups at 7 days. In contrast to that in DBB and ß-TCP groups, ECP displayed growing bone volume over total volume percentage (BV/TV%) with time in vivo. Histological analysis revealed a greater number of giant cells and reduced size of grafted particles in ECP during all periods of analysis. RUNX-2 expression was statistically lower in ECP than DBB at 2 and 4 weeks. Despite no statistical significance, ECP presented the highest absolute values for ALP-expression at 2, 4, and 8 weeks compared with other groups. Together, our findings indicate that a combination of the ACP, OCP, and HA phases into ECP is beneficial and promising for bone regeneration.

Perspectivas atuais da Engenharia de Tecidos da articulação temporomandibular / Perspectivas Actuales de la Ingeniería de Tejidos para la Articulación Temporomandibular / Current Perspectives of Tissue Engineering for the Temporomandibular Joint

Introdução: As limitações das terapias atuais para doenças degenerativas da articulação temporomandibular (ATM) levaram ao aumento do interesse em estratégias regenerativas. A engenharia de tecidos (ET), combinando células-tronco, arcabouços e fatores de crescimento, pode fornecer uma substituição biológica funcional e permanente das estruturas da ATM, além de prevenir o avanço de doenças degenerativas. Objetivo: Este artigo descreve as perspectivas atuais da ET das estruturas da ATM em modelos animais. Metodologia: As abordagens da ET foram categorizadas de acordo com as estruturas primárias da ATM: 1) o disco articular, 2) o côndilo mandibular e 3) a fossa glenóide e eminência articular. Resultados: As áreas com a maior quantidade de estudos são o côndilo mandibular e disco articular, em estudos que abordam o uso de arcabouços tridimensionais, de origem sintética e/ou natural, podendo ou não estar associados a células tronco (diferenciadas ou não) e a fatores de crescimento. Conclusão: A ET da ATM ainda é uma área relativamente nova, em desenvolvimento e em constante avanço. Os avanços tecnológicos desenvolvidos nessa área têm o potencial de auxiliar no desenvolvimento de terapias mais eficientes e menos invasivos... (AU)

Introducción: Las limitaciones de las terapias actuales para las enfermedades degenerativas de la articulación temporomandibular (ATM) han llevado a un mayor interés en las estrategias regenerativas. La ingeniería de tejidos, que combina células, andamios y factores de crecimiento, puede proporcionar un reemplazo biológico funcional y permanente de las estructuras de la ATM, además de prevenir el avance de enfermedades degenerativas. Objetivo: Este artículo describe las perspectivas actuales de la ingeniería de tecidos de las estructuras de la ATM en modelos animales. Metodología: Los enfoques de ingeniería de tejidos se clasificaron según las estructuras primarias de la ATM: 1) el disco articular, 2) el cóndilo mandibular y 3) la fosa glenoidea y la eminencia articular. Resultados: Las áreas con mayor número de estudios son el cóndilo mandibular y el disco articular, en estudios que abordan el uso de estructuras tridimensionales, de origen sintético y/o natural, que pueden o no estar asociadas a células (diferenciadas o no) y con factores de crecimiento. Conclusión: La ingeniería de tejidos de la ATM es todavía un área relativamente nueva, en desarrollo y em constante avance. Los avances tecnológicos desarrollados en esta área tienen el potencial de ayudar en el desarrollo de terapias más eficientes y menos invasivas... (AU)

Introduction: The limitations of current therapies for degenerative diseases of the temporomandibular joint (TMJ) have led to increased interest in regenerative strategies. Tissue engineering (TE), combining stem cells, scaffolds, and growth factors, can provide a functional and permanent biological replacement of TMJ structures, in addition to preventing the advancement of degenerative diseases. Aim: This article describes current TE perspectives of TMJ structures in animal models. Methods: TE approaches were categorized according to the primary TMJ structures: 1) the articular disc, 2) the mandibular condyle, and 3) the glenoid fossa and articular eminence. Results: The areas with the greatest number of studies are the mandibular condyle and articular disc, in studies that address the use of three-dimensional scaffolds, of synthetic and/or natural origin, which may or may not be associated with stem cells (differentiated or not) and with growth factors. Conclusion: TE of the TMJ is still a relatively new, developing, and constantly advancing area. The technological advances developed in this area have the potential to assist in the development of more efficient and less invasive therapies... (AU)

Perspectivas atuais da engenharia de tecidos da articulação temporomandibular / Perspectivas Actuales de la Ingeniería de Tejidos para la Articulación Temporomandibular / Current Perspectives of Tissue Engineering for the Temporomandibular Joint

Introdução: As limitações das terapias atuais para doenças degenerativas da articulação temporomandibular (ATM) levaram ao aumento do interesse em estratégias regenerativas. A engenharia de tecidos (ET), combinando células-tronco, arcabouços e fatores de crescimento, pode fornecer uma substituição biológica funcional e permanente das estruturas da ATM, além de prevenir o avanço de doenças degenerativas. Objetivo: Este artigo descreve as perspectivas atuais da ET das estruturas da ATM em modelos animais. Metodologia: As abordagens da ET foram categorizadas de acordo com as estruturas primárias da ATM: 1) o disco articular, 2) o côndilo mandibular e 3) a fossa glenóide e eminência articular. Resultados: As áreas com a maior quantidade de estudos são o côndilo mandibular e disco articular, em estudos que abordam o uso de arcabouços tridimensionais, de origem sintética e/ou natural, podendo ou não estar associados a células tronco (diferenciadas ou não) e a fatores de crescimento. Conclusão: A ET da ATM ainda é uma área relativamente nova, em desenvolvimento e em constante avanço. Os avanços tecnológicos desenvolvidos nessa área têm o potencial de auxiliar no desenvolvimento de terapias mais eficientes e menos invasivos... (AU)

Introducción: Las limitaciones de las terapias actuales para las enfermedades degenerativas de la articulación temporomandibular (ATM) han llevado a un mayor interés en las estrategias regenerativas. La ingeniería de tejidos, que combina células, andamios y factores de crecimiento, puede proporcionar un reemplazo biológico funcional y permanente de las estructuras de la ATM, además de prevenir el avance de enfermedades degenerativas. Objetivo: Este artículo describe las perspectivas actuales de la ingeniería de tecidos de las estructuras de la ATM en modelos animales. Metodología: Los enfoques de ingeniería de tejidos se clasificaron según las estructuras primarias de la ATM: 1) el disco articular, 2) el cóndilo mandibular y 3) la fosa glenoidea y la eminencia articular. Resultados: Las áreas con mayor número de estudios son el cóndilo mandibular y el disco articular, en estudios que abordan el uso de estructuras tridimensionales, de origen sintético y/o natural, que pueden o no estar asociadas a células (diferenciadas o no) y con factores de crecimiento. Conclusión: La ingeniería de tejidos de la ATM es todavía un área relativamente nueva, en desarrollo y en constante avance. Los avances tecnológicos desarrollados en esta área tienen el potencial de ayudar en el desarrollo de terapias más eficientes y menos invasivas... (AU)

Introduction: The limitations of current therapies for degenerative diseases of the temporomandibular joint (TMJ) have led to increased interest in regenerative strategies. Tissue engineering (TE), combining stem cells, scaffolds, and growth factors, can provide a functional and permanent biological replacement of TMJ structures, in addition to preventing the advancement of degenerative diseases. Aim: This article describes current TE perspectives of TMJ structures in animal models. Methods: TE approaches were categorized according to the primary TMJ structures: 1) the articular disc, 2) the mandibular condyle, and 3) the glenoid fossa and articular eminence. Results: The areas with the greatest number of studies are the mandibular condyle and articular disc, in studies that address the use of three-dimensional scaffolds, of synthetic and/ or natural origin, which may or may not be associated with stem cells (differentiated or not) and with growth factors. Conclusion: TE of the TMJ is still a relatively new, developing, and constantly advancing area. The technological advances developed in this area have the potential to assist in the development of more efficient and less invasive therapies... (AU)

Evaluation of antimicrobial photodynamic therapy with acidic methylene blue for the treatment of experimental periodontitis.

OBJECTIVE: To investigate the security and effectiveness of antimicrobial photodynamic therapy (aPDT) with a citric acid-based methylene blue (MB) on the periodontal repair following the treatment of ligature-induced experimental periodontitis (EP) in rats. MATERIAL AND METHODS: Were used 120 male rats, randomly divided into 4 experimental groups (n = 30): no treatment (NT), SRP alone (SRP), SRP plus aPDT using conventional MB pH 7.0 (aPDT-pH7), SRP plus aPDT using acidic MB pH 1.0 (aPDT-pH1). EP was induced at day 0 by the placement of a ligature around the mandibular left first molars. Ten animals per group/period were euthanized at 14, 22 and 37 days. Histopathological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (for tartrate-resistant acid phosphatase [TRAP] and osteocalcin [OCN]) analyses were performed. Data were statistically analyzed. RESULTS: aPDT-pH1 showed the highest PBF as compared with the other treatments. Collectively, tissues' reaction to both dyes were controlled and healthy for the periodontium. Both aPDT protocols reduced the extent and intensity of the local inflammatory response, reduced the alveolar bone resorption, and promoted a better structural arrangement of the connective tissue as compared with SRP. TRAP expression was downregulated while OCN expression was upregulated by aPDT as compared with SRP alone. CONCLUSION: Our data implicate that the novel MB pH 1.0 is as safe as the conventional MB for use in aPDT and raises its additional benefit of increasing the amount of alveolar bone in the furcation.

The influence of antineoplastic agents on the peri-implant bone around osseointegrated titanium implants: an in vivo histomorphometric and immunohistochemical study.

BACKGROUND AND OBJECTIVE: The interaction between antineoplastic drugs used for treating cancer and non-affected tissues remains poorly assessed and may be critical for maintaining the quality of life for patients during and after treatment. This pre-clinical study evaluated the effects of cisplatin (CIS) and 5-fluorouracil (5-FU) on the peri-implant repair process around osseointegrated titanium implants installed in the tibiae of rats. MATERIAL AND METHODS: Were used 90 male rats, randomly divided into three groups (n = 30): physiological saline solution (PSS), CIS, and 5-FU. Titanium implants (4.0 × 2.2 mm) were inserted in both tibiae of all animals at day 0. The animals received either PSS, CIS, or 5-FU at 35 and 37 days. Euthanasia was performed at 50, 65, and 95 days after surgery. Histometric (bone/implant contact [BIC]) and bone area fraction occupancy (% BAFO), histological, and immunohistochemical (for bone morphogenetic protein 2/4 [BMP2/4], Runt-related transcription factor 2 [RUNX2], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analyses were performed. Data were statistically analyzed. RESULTS: Groups CIS and 5-FU presented lower BIC and lower BAFO as compared with PSS in all time points. The imbalance in bone turnover was observed by the lower number of BMP2/4-, RUNX2-, and OCN-positive cells/mm2 and the higher number of TRAP-positive cells/mm in groups CIS and 5-FU as compared with PSS in all time points. Persistent and exacerbated inflammation was observed in groups CIS and 5-FU. CONCLUSIONS: Both antineoplastic agents interfered negatively in the bone turnover around osseointegrated titanium implants. CLINICAL RELEVANCE: Closer and more careful follow-up of patients with osseointegrated implants that will undergo chemotherapy with either CIS or 5-FU shall be performed.

Antineoplastic agents aggravate the damages caused by nicotine on the peri-implant bone: an in vivo histomorphometric and immunohistochemical study in rats.

OBJECTIVE: To assess the interaction between chemotherapy and normal tissues is critical to assure quality of life during and after the treatment of cancer. This study evaluated the influence of cisplatin (CIS) and 5-fluorouracil (5-FU) over the peri-implant tissues around osseointegrated titanium implants in animals previously exposed to nicotine. Materials and methods One hundred twenty male rats were divided into two groups, receiving via subcutaneous injection, either physiological saline solution (PSS) (n = 30) or nicotine hemissulfate (NIC) (n = 90) for 30 days prior to implants' placement. One titanium implant (4.0 × 2.2 mm) was installed in each tibia of all animals. PSS and NIC were continued for 30 days after surgery. Five days after cessation, rats were subdivided into three subgroups in accordance with systemic treatments with either PSS, CIS, or 5-FU. Euthanasia was performed at 50, 65, and 95 days post-surgery. Histometric, histopathological, and immunohistochemical analyses were performed. RESULTS: NIC-CIS and NIC-5FU presented lower BIC (50, 65, and 95 days) and bone area fraction occupancy (BAFO) (65 and 95 days) than group NIC. Intense inflammatory infiltration, severe tissue breakdown, reduced expression of bone formation biomarkers, and upregulation of TRAP were observed in NIC-CIS and NIC-5FU when compared with group NIC. TRAP expression was significantly higher in NIC-5FU as compared with NIC-CIS at 50 and 95 days. Groups NIC, NIC-CIS, and NIC-5FU presented statistically significant negative impact in all outcome parameters than group PSS. CONCLUSION: CIS and 5-FU severely disrupted the peri-implant tissues around osseointegrated implants in animals previously exposed to nicotine. CLINICAL RELEVANCE: Assessing the interaction between chemotherapy and normal tissues is critical to assure quality of life during and after the cancer treatment.

Influence of immunosuppression on the progression of experimental periodontitis and on healthy periodontal tissue: A rat in vivo study.

Background. The potent anti-inflammatory and immunosuppressive properties of glucocorticoids (GCs) might influence the progression of some disorders, such as periodontitis. Hence, this study aimed to investigate the influence of dexamethasone (DEX) on the alveolar bone loss (ABL) of healthy and periodontally compromised molars in rats. Methods. Thirty male rats were randomly assigned to two groups: physiological saline solution (PSS) and DEX. The animals received subcutaneous injections of either 0.5 mL of PSS) (group PSS) or 2 mg/kg of DEX (group DEX) from one day before experimental periodontitis (EP) induction until euthanasia. EP was induced through ligature placement around the mandibular lower first molars at day 0. Contralateral molars remained unligated. Ten animals per period were euthanized on days 3, 7, and 14. Morphometric analysis was performed to access the ABL. Data were statistically analyzed with ANOVA followed by post hoc Tukey tests (P ≤ 0.05). Results. Higher ABL was observed in both groups on days 7 and 14 than on day 3 (P ≤ 0.05). Concerning periodontitis, higher ABL was observed in group DEX on days 3, 7, and 14 days than group PSS at the same time intervals (P ≤ 0.05). Also, even in the contralateral unligated molars, group DEX exhibited higher ABL on days 3, 7, and 14 days than group PSS at the same time intervals (P ≤ 0.05). Conclusions. Collectively, it can be concluded that DEX aggravates EP and induces spontaneous ABL in the healthy periodontium.

Platelet-rich fibrin for wound healing of palatal donor sites of free gingival grafts: Systematic review and meta-analysis.

BACKGROUND: Platelet-rich fibrin (PRF) has been referred to as a second-generation platelet concentrate, associated with improvements on the healing of palatal wounds followed by FGG harvesting. The aim of this systematic review and meta-analysis was to assess the complete wound epithelialization and postoperative pain when PRF was used in palatal wounds following free gingival graft (FGG) harvesting. MATERIAL AND METHODS: PubMed (Medline), EMBASE and Scopus were searched by two independent individuals up to and including March 2020 in order to identify controlled and randomized controlled clinical trials on the use of PRF at palatal donor sites of FGG. The outcomes assessed were epithelialization and postoperative pain. The risk of bias of the included studies was evaluated using Cochrane Collaboration's domain-based two-part tool. Random effects meta-analyses were conducted with 95% confidence intervals. RESULTS: The search strategy identified 555 potentially eligible articles, of which 6 randomized controlled clinical trials were included. In the qualitative analysis, most studies (83.3%) reported lower postoperative pain in treatment groups, while all studies accessing epithelialization demonstrated earlier complete wound closure in groups treated with PRF. The discomfort and complete re-epithelialization were more favorable in groups PRF when compared to control groups (P<0.00001). CONCLUSIONS: Within the limits of the present study, it can be concluded that the use of PRF for wound healing of palatal donor sites of FGG may decrease postoperative pain and induce earlier complete wound epithelialization. Key words:Wound healing, oral surgery procedures, pain, postoperative.

Influence of systemic strontium ranelate on the progression and as adjunctive therapy for the nonsurgical treatment of experimental periodontitis.

BACKGROUND: Strontium Ranelate (SR) presents overlapping osteoanabolic and anti-resorptive activity. However, the effects of SR on the progression of periodontitis through the alveolar bone and its potential applicability as adjunctive therapy to scaling and root planning remain poorly accessed. The aim of this study was to evaluate the effects of systemic (SR) both on the progression of experimental periodontitis (EP) and as adjunctive therapy to SRP. MATERIAL AND METHODS: Eighty male rats were divided into four groups (n=20): EP-PSS: EP induction and systemic administration of physiological saline solution (PSS); EP-SR: EP induction and systemic administration of SR; EP-SRP/PSS: EP induction, SRP and systemic administration of PSS; EP-SRP/SR: EP induction, SRP and systemic administration of SR. Seven days after ligature placement, SRP was performed in EP-SRP/PSS and EP-SRP/SR, as well as the systemic administration of either PSS or SR were initiated and continued until euthanasia in all groups. Animals were euthanized at 7 and 30 days after the beginning of the systemic treatments. Histological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (tartrate-resistant acid phosphatase [TRAP], Osteocalcin [OCN] and leukocyte common antigen [CD 45]) analyses were performed. Data were statistically analyzed. RESULTS: EP-SRP/PSS showed a significantly more organized pattern of the connective tissue and alveolar bone structure than EP-SRP/SR. EP-SR showed significantly higher PBF than EP-PSS, however, EP-SRP/PSS showed no difference with EP-SRP/SR at 30 days. CONCLUSIONS: SR reduced the alveolar bone loss in non-treated animals and presented no standout benefits over the conventional forms of treating EP. Key words:Strontium Ranelate, periodontal disease, root planing, alveolar bone loss.

Influence of adjuvant therapy with green tea extract in the treatment of experimental periodontitis.

AIM: This study evaluated the effects of topical green tea extract solution (GTE) as adjuvant therapy to mechanical debridement for the treatment of experimental periodontitis (EP). MATERIAL AND METHODS: We used 120 male rats (Rattus norvegicus albinus - Wistar), divided into the following four groups: NEP (sham) (n = 30): no experimental periodontitis (NEP), only simulation of EP by installation and removal of a ligature; EP (n = 30): EP induction by ligature; SRP (n = 30): EP, scaling and root planing (SRP), and irrigation with physiological saline solution; SRP/GT (n = 30): EP, SRP, and irrigation with GTE. Histologic analysis and immunohistochemistry were performed for detection of interleukin (IL)1ß, tumor necrosis factor-alpha (TNF-α), IL-10, and anti-tartrate resistant acid phosphatase (TRAP) in the furcation area. The percentage of bone in the furcation (PBF) was considered the primary variable and evaluated at 14, 22, and 37 days. The data from the histological analysis and the IL- 1B, TNF- A, and IL-10 were submitted to a Kruskal-Wallis variance test and Dunn's posttest (p ≤ 0.05). The histometric data and TRAP were submitted to analysis of variance (ANOVA) and Tukey's posttest (p ≤ 0.05). RESULTS: The SRP/GT group showed lower inflammatory process, lower immunolabeling pattern of IL-1ß and TNF-α, and greater immunolabeling pattern of IL-10 compared with the EP and SRP groups at 22 days. Fewer TRAP-positive multinucleated osteoclasts were observed in all periods in the SRP/GT group (5.22 ± 0.65; 7.33 ± 0.80; 8.55 ± 1.15) compared with the SRP group (30.67 ± 8.55; 13.22 ± 0.77; 13.87 ± 0.77). Higher PBF was observed in all periods in the SRP/GT group (74.65 ± 7.14; 76.61 ± 5.36; 79.24 ± 3.75) compared with the SRP group (61.60 ± 9.48; 54.84 ± 9.06; 53.25 ± 9.66). CONCLUSION: GTE adjuvant to SRP reduced inflammation, osteoclastic activity, and alveolar bone loss in EP.

Antineoplastic agents exacerbate periodontal inflammation and aggravate experimental periodontitis.

AIM: This study evaluated the effects of 5-fluorouracil (5-FU) and cisplatin (CIS) in healthy periodontal tissues and in the early stages of experimental periodontitis (EP) in rats. METHODS: One hundred and eighty male rats were divided into three groups, which were submitted to the following systemic treatments: physiological saline solution (PSS); CIS and 5FU. Each group was subdivided into two subgroups: without (NEP) and with (EP) induction of EP. Animals were euthanized at 3, 5 and 7 days post-treatment. Histological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (for tumour necrosis factor-α, interleukin-1ß and receptor activator of nuclear factor-κB ligand) analyses were performed. Data were statistically analysed. RESULTS: CIS-NEP and 5FU-NEP showed more inflammation than PSS-NEP at 3, 5 and 7 days. CIS-EP and 5FU-EP showed more inflammation and lower PBF than PSS-EP at all periods of evaluation. 5FU-EP showed lower PBF than CIS-EP at 5 and 7 days. CONCLUSION: 5-FU and CIS exacerbated periodontal inflammation and aggravated the progression of EP in its early stages.

Avaliação da influência da quimioterapia com cisplatina ou 5-fluorouracil sobre o processo de reparo ósseo em implantes osseointegrados instalados em tíbias de ratos expostos ou não à nicotina / Evaluation of the influence of Cisplatin or 5-fluorouracil over the bone repair process around osseointegrated implants installed in tibiae of rats exposed or not to nicotine

Objetivo: avaliar a influência da nicotina e dos agentes antineoplásicos Cisplatina (CIS) e 5-fluorouracil (5-FU) sobre os tecidos peri-implantares, bem como os efeitos desses agentes antineoplásicos sobre os tecidos peri-implantares em animais previamente expostos à nicotina. Material e métodos: 180 ratos machos (Wistar) foram randomizados para dois grandes grupos (n=90), NIC e SS, em seguida, para três subgrupos (n=30) de acordo com os agentes antineoplásicos. Receberam 0,5ml de solução de cloreto de sódio 0,9% (SS) ou 3 mg/kg de hemissulfato de nicotina (NIC), de acordo com cada grupo, 30 dias antes e 30 dias após a cirurgia. No dia 0, todos os animais receberam os implantes de titânio (DSP Biomedical®, 4 mm x 2,2 mm) nas tíbias direita e esquerda. Aos 30 dias após a cirurgia, as aplicações de SS e NIC foram interrompidas por 5 dias e, aos 35 e 37 dias, foram administrados os agentes antineoplásicos CIS, 5-FU ou 0,5 ml de SS, via intraperitoneal, respeitando intervalo de 48 h entre as aplicações. Para CIS, 5 mg/kg e 2,5 mg/kg, e para 5- FU, 60 mg/kg e 40 mg/kg, respetivamente. SS-SS: receberam SS via subcutânea e intraperitoneal. SS-CIS: receberam SS via subcutânea e CIS via intraperitoneal. SS-5FU: receberam SS via subcutânea e 5-FU via intraperitoneal. NIC-SS: receberam NIC via subcutânea e SS via intraperitoneal. NIC-CIS: receberam NIC via subcutânea e CIS via intraperitoneal. NIC-5FU: receberam NIC via subcutânea e 5-FU via intraperitoneal. Dez animais por grupo/período foram eutanasiados aos 50, 65 e 95 dias após instalação dos implantes de titanio. Os especimes coletados foram fixados em formaldeido tamponado 4% por 48h e destinados para processamento sem desmineralizacao para analise do contato osso/implante (COI), ou processamento com desmineralizacao e inclusao em parafina para análises histométrica de porcentagem de tecido ósseo neoformado (PTON), histológica, e imunoistoquímica para detecção de BMP2/4, RUNX2, OCN e TRAP. Outros espécimes foram fixados em glutaraldeído 2,5% e tampão cacodilato 0,1M para análise ultraestrutural sob microscopia eletrônica de varredura (MEV). Resultados: SS-SS apresentou maior COI quando comparado aos demais grupos. SS-CIS e SS-5FU apresentaram maior COI quando comparados com NIC-CIS e NIC-5FU, respectivamente. NIC-SS apresentou maior COI quando comparado com NIC-CIS e NIC-5FU, sendo que NIC-5FU apresentou os piores resultados. SS-SS apresentou maior PTON quando comparado aos demais grupos. SS-CIS e SS-5FU apresentaram menor PTON aos 50 dias, e em todos os periodos, quando comparados com NIC-CIS e NIC-5FU, respectivamente. NIC-CIS apresentou maior PTON aos 65 dias quando comparado com NIC-5FU. A analise histologica dos tecidos periimplantares mostrou que CIS e 5-FU comprometem sua estrutura geral. O tratamento com nicotina tambem compromete o padrao de celularidade e estruturacao da matriz extracelular dos tecidos peri-implantares, o que e severamente agravado quando da associacao com agentes antineoplasicos. SS-SS apresentou maior numero de celulas BMP2/4, RUNX2 e OCN-positivas/mm2 quando comparado aos demais grupos. SS-SS apresentou menor numero de celulas TRAP-positivas/mm quando comparado com os demais grupos. A avaliacao imunoistoquimica para cada biomarcador indicou que os piores resultados foram observados nos grupos NIC-CIS e NIC-5FU quando comparados com os demais grupos. A analise ultraestrutural da interface osso/implante mostrou estruturacao tecidual e organizacao celular em SS-SS. Gap e desestruturacao tecidual foram observados no demais grupos, sendo que os piores resultados foram observados nos grupos com nicotina. Conclusão: tanto nicotina quanto agentes antineoplasicos, isoladamente, sao capazes de afetar negativamente os tecidos peri-implantares, sendo que a animais expostos a ambas substancias apresentam comprometimento mais severo desses tecidos(AU)

Objective: to evaluate the influence of nicotine and the antineoplastic agents Cisplatin (CIS) and 5-fluorouracil (5-FU) over the peri-implant tissues, as well as the effects of these agents over peri-implant tissues in animals previously exposed to nicotine. Material and Methods: 180 male rats (Wistar) were initially randomized to two groups (n=90), NIC and SS. Then, to three subgroups (n=30) according to the protocol of antineoplastic agents. Received 0.5 ml of sodium chloride 0.9% (SS) or 3 mg/kg of nicotine hemissulfate (NIC) according to each group, subcutaneously, 30 days before and after surgical procedure for implants placement. At day 0, all animals received the titanium implants (DSP Biomedical®, 4 mm x 2.2 mm) in both right and left tibiae. At 30 days after surgery SS and NIC was interrupted, and at 35 and 37 days were intraperitoneally administered the antineoplastic agents CIS, 5FU or 0.5 ml SS, with 48 h interval between applications. For CIS, 5 mg/kg and 2,5 mg/kg, and 5-FU, 60 mg/kg and 40 mg/kg, respectively. SS-SS: received SS subcutaneously and intraperitoneally. SS-CIS: received SS subcutaneously and CIS intraperitoneally. SS-5FU: received SS subcutaneously and 5-FU intraperitoneally. NIC-SS: received NIC subcutaneously and SS intraperitoneally. NIC-CIS: received NIC subcutaneously and CIS intraperitoneally. NIC-5FU: received NIC subcutaneously and 5-FU intraperitoneally. Ten animals per group and period were euthanized at 50, 65 and 95 days after implants placement. The collected specimens were fixed in buffered formaldehyde solution 4% for 48h and assigned to ground section processing for analysis of bone/implant contact (BIC), or conventional histologic processing with demineralization and paraffin embedding for histometric analysis of percentage of newly-formed bone (PNFB), histologic and immunohistochemistry for detection of BMP2/4, RUNX2, OCN and TRAP. Other specimens were fixed in 2.5% glutaraldehyde and cacodilate buffer 0.1M for ultrastructural analysis under scanning electron microscopy (MEV). Results: SS-SS showed higher BIC when compared with the other groups. SS-CIS and SS-5FU showed higher BIC when compared with NIC-CIS and NIC-5FU respectively. NIC-SS showed higher BIC when compared with NIC-CIS and NIC-5FU, and NIC-5FU showed the worst results. SS-SS showed higher PNFB when compared with the other groups. SS-CIS and SS-5FU showed higher PNFB at 50 days and in all periods when compared with NIC-CIS and NIC-5FU respectively. NIC-CIS showed higher PNFB at 65 days when compared with NIC-5FU. The histologic analysis of the peri-implant tissues showed that CIS and 5-FU jeopardize its general structure. The treatment with nicotine also compromises the cellularity and structural patterns of the extracellular matrix of peri-implants tissues, and the association of both agents exacerbates tissues' disruption. SS-SS showed higher number of BMP2/4, RUNX2 and OCN-positive cells/mm2 when compared with the other groups. SS-SS showed lower number of TRAP-positive cells/mm when compared with the other groups. The immunohistochemical analysis for each biomarker indicated that the worst results were observed in groups NIC-CIS and NIC-5FU when compared with the other groups. The ultrastructural analysis of the interface between bone/implant showed great tissue structuring and cell arrangement in SS-SS. Gap and tissues' disruption were observed in the other groups, with the worst results for the ones receiving nicotine. Conclusion: both nicotine and antineoplastic agents, even when isolated, are capable to negatively affect the peri-implant tissues, and animals exposed to both substances show the most compromising effects over these tissues(AU)

Cisplatin chemotherapy impairs the peri-implant bone repair around titanium implants: An in vivo study in rats.

AIM: The purpose of this study in animals was to evaluate the peri-implant bone repair against systemic administration of the antineoplastic agent. MATERIAL AND METHODS: We used 84 male rats (Rattus norvegicus, albinus, Wistar), divided into two groups: cisplatin (CIS) and saline solution (SS). The titanium implants were inserted into the right tibia at day 0 in all animals from both groups. Group SS received SS intraperitoneally at 15 and 17 days postoperatively. Group CIS received 5 and 2.5 mg/kg of CIS intraperitoneally at 15 and 17 days postoperatively, respectively. Euthanasia was performed at 22, 30 and 60 days postoperatively. Twenty-four undecalcified specimens were prepared for histometric analysis of bone/implant contact (BIC). Sixty specimens were selected to bone area (BA) measurement, histological analysis and immunohistochemical analysis of RUNX-2, osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP). BIC and BA were considered to be the primary outcome parameters. RESULTS: Group CIS showed lower BIC (11.87 ± 0.97 mm; 19.19 ± 0.8 mm; 17.69 ± 1.05 mm; p ≤ .05) and BA (3.68 ± 1.29 mm2 ; 3.05 ± 0.88 mm2 ; 3.23 ± 0.67 mm2 ; p ≤ .05), as well as decreased number of RUNX-2 (102.8 ± 27.35 cells/mm2 ; 100.04 ± 8.61 cells/mm2 ; 118.82 ± 21.38 cells/mm2 ; p ≤ .05)- and OCN-positive cells (120 ± 24.5 cells/mm2 ; 102 ± 27.73 cells/mm2 ; 100 ± 14.23 cells/mm2 ; p ≤ .05) at 22, 30 and 60 days, respectively. The animals in group CIS also showed increased number of TRAP-positive cells (86.8 ± 6.37 cells/mm2 ; 71.5 ± 4.72 cells/mm2 ; 92.8 ± 9.52 cells/mm2 ; p ≤ .05) and a persistent and exacerbated inflammatory response in all experimental periods. CONCLUSION: Within the limits of this study, it was concluded that the chemotherapeutic CIS negatively affects the bone repair at peri-implant areas, jeopardizing the osseointegration of titanium implants.

pH influences the biocompatibility of methylene blue solutions.

OBJECTIVE: The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue. MATERIALS AND METHODS: Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)-empty tube, fibrin group (G-F)-tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)-tube filled with fibrin sponge soaked by methylene blue (100 µg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)-tube filled with fibrin sponge and soaked by methylene blue (100 µg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 µm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal-Wallis test (p ≤ 0.05). RESULTS: At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups. CONCLUSION: Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

A photoelastic and strain gauge comparison of two attachments for obturator prostheses.

STATEMENT OF PROBLEM: The rehabilitation of patients after a maxillectomy involves the use of an obturator to seal oral-nasal-sinus communication and to facilitate mastication, swallowing, and speech. PURPOSE: The purpose of this in vitro study was to evaluate different attachment systems used for implant-retained obturators at dissipation loads and under shear forces. MATERIAL AND METHODS: Photoelastic models were fabricated with 3 external hexagon implants at the incisor, canine, and first molar regions. Subsequently, overdentures were made, and metal hooks were placed at the incisor and first molar regions to displace the prostheses in the vertical, anterior, and posterior directions, with a constant speed of 50 mm/min. A photoelastic model with an O-ring or bar-clip system was placed in a circular polariscope, and tested with a universal testing machine. The images were recorded and high-intensity fringes were counted using software. For strain gauge analysis, each strain gauge was placed horizontally at the mesial and distal sides of the implants. The registered strains were submitted to 2-way ANOVA (α=.05). RESULTS: The O-ring showed the lowest number of high-intensity fringes in photoelastic imaging, while the strain gauge analysis showed the lowest stress values in the bar-clip group (P=.007). CONCLUSIONS: The stress around titanium implant necks was more damaging to surrounding bone, while the bar-clip attachment system had a better biomechanical performance. The bar-clip presented the lowest strain values around the dental implants and few high-intensity fringes.