Porcine Resorbable Collagen Matrix Shows Good Incorporation of Liquid Platelet-Rich Fibrin In Vitro.

Purpose: To evaluate the incorporation of liquid platelet-rich fibrin in different collagen matrices in vitro. Materials and Methods: Collagen matrices with liquid platelet-rich fibrin were used and divided into the following test groups (n = 5): Mucoderm (MD), Mucograft (MG), and Fibro-Gide (FG). After incubating the collagen matrices in liquid platelet-rich fibrin, histologicl and fluid absorption capacity analysis were performed. Intergroup comparisons of cell count, blood plasma penetration area, and fluid absorption capacity were performed using one-way ANOVA and Tukey tests. Intragroup comparisons of fluid absorption capacity were made using the independent t test with a 5% significance level. Results: Descriptive qualitative analysis showed total incorporation of liquid platelet-rich fibrin in the FG group, while the MG and MD groups showed only partial and shallow incorporation, respectively. There was a statistically significant difference among the three groups regarding inflammatory cell infiltration (P = .000), with the FG group presenting the highest number of cells in the matrices (577.15 ± 54.88). The FG group showed an area of total blood plasma penetration into the matrix, followed by the MG group with partial penetration, and the MD group with minor penetration area (P = .000). Considering the fluid absorption capacity analysis, only groups FG and MG were statistically different when comparing the liquid platelet-rich fibrin absorption coefficient (P = .017), with higher absorption in group FG (14.30 ± 3.35). Conclusions: The FG collagen matrix showed a good capacity for liquid platelet-rich fibrin incorporation in vitro.

Comparison of Gingival Recession of Mandibular Incisors of Class III Patients Immediately after Compensatory or Surgical Orthodontic Treatment.

OBJECTIVE: This study aimed to compare gingival recession in mandibular anterior teeth in patients with Class III malocclusion, immediately after compensatory or surgical orthodontic treatment. MATERIALS AND METHODS: The sample consisted of 40 patients with Class III malocclusion, divided into two groups: Group 1 (compensatory), 20 patients treated with compensatory orthodontics, with a mean initial age of 20.26 years (standard deviation [SD] . = 7.44), mean final age of 23.07 years (SD = 7.32), and mean treatment time of 2.81 years (SD =0.84). Group 2 (surgical), who undergone orthodontic-surgical treatment, with a mean initial age of 23.08 years (SD =5.48), mean final age of 25.43 years (SD =5.12), and mean treatment time of 2.35 years (SD =1.56). Intraoral photographs taken before and after removal of the fixed orthodontic appliance were used to measure the gingival recession, from the cervical of the mandibular incisors from the most cervical point of the gingival margin to the cementoenamel junction. In the initial and final cephalograms, the position of the mandibular incisors was measured. The intergroup comparison was performed using the independent t-test. RESULTS: The results showed that there was no statistically significant difference in the gingival recession at the beginning, at the end, and of changes with treatment between the compensatory and surgical groups. CONCLUSION: It was concluded that the compensatory and surgical orthodontic treatments for Class III malocclusion showed similar results regarding the gingival recession of the mandibular incisors.

Gingival recession in mandibular anterior teeth in patients with Class II malocclusion treated with elastics and Twin Force appliance.

INTRODUCTION: This study aimed to compare the early results of gingival recession in patients with Class II malocclusion treated with Class II intermaxillary elastics and the Twin Force appliance. METHODS: The sample comprised 55 patients with Class II malocclusion treated without extraction and divided into 2 groups. Group 1 consisted of 23 patients treated with fixed appliances and Class II elastics, with mean initial age of 15.41 ± 5.65 years and a mean treatment time of 3.11 ± 0.91 years. Group 2 consisted of 32 patients treated with fixed appliances and the Twin Force mandibular protraction appliance, with a mean initial age of 18.45 ± 6.63 years and a mean treatment time of 3.17 ± 1.59 years. Dolphin software measured gingival recession in initial and final intraoral photographs. Initial and final lateral cephalograms were used to measure the position of the mandibular incisors. Intragroup and intergroup comparisons were performed by dependent and independent t tests, respectively. RESULTS: In both groups, there was no significant increase in gingival recession with orthodontic treatment, and there was significant protrusion and buccal inclination of the mandibular incisors. When changes with treatment were compared between the groups, there was no statistically significant difference in gingival recession and mandibular incisor position. CONCLUSIONS: There was no significant increase in gingival recession immediately after orthodontic treatment performed with intermaxillary elastics and the Twin Force appliance.

Efficacy of Low-Level Laser Therapy in Reducing Pain in the Initial Stages of Orthodontic Treatment.

Purpose: There is no consensus about the mechanism and efficacy in alleviating pain of the lower-level laser therapy (LLLT) during orthodontic treatment. This study aimed to evaluate the LLLT effectiveness clinically in reducing pain caused by orthodontic movement that occurs in the early stages of treatment. Methods: The sample consisted of 54 patients in need of orthodontic treatment divided into two groups. A 28 experimental patients group (initial mean age: 26.84 years old) was undergone gallium-aluminum-arsenide infrared laser application on 12 points for each tooth immediately after the installation of the first alignment archwire, and a 26 patients control group (initial mean age: 29.13 years old) was undergone to no pain control intervention at all. Pain intensity was measured by using a visual analog scale, which was marked pain level (mm) reported in 06, 24, 48, and 72 hours. The perception of pain (beginning, peak, decline, and absence) was evaluated by filling up a questionnaire. To compare the intensity and perception of pain between groups, a nonparametric Mann-Whitney has been performed. Results: The experimental group showed levels (mm) at 6 (p < 0.001), 24 (p=0.004), and 48 hours (p=0.007) and perception of pain (hours) in the peak (p=0.026), decline (p=0.025), and absence (p=0.008) significantly lower compared to the group control. Conclusion: Low-level laser therapy is effective in reducing pain severity caused by orthodontic forces activation, and it promotes the analgesic action lasting effect during the most painful feeling time.

Sodium Bicarbonate Jet Reduces Contamination of Dental Implants In Vitro Without Causing Visible Surface Changes.

PURPOSE: The increasing use of dental implants in oral rehabilitation has contributed to the increase of cases of peri-implantitis, a complex clinical condition that persists without an ideal treatment protocol. Therefore, this study aimed to verify the decontaminating action of the sodium bicarbonate jet in vitro, using different protocols, and the presence of visible changes on the surface of dental implants. MATERIALS AND METHODS: Sixteen titanium implants (BioHE, Bioconnect) were used, divided into four groups (four implants per group): sterile implants (S)-negative control; implants contaminated with oral biofilm (C)-positive control; and implants contaminated with oral biofilm and decontaminated with a sodium bicarbonate jet for 30 seconds (J30) or 60 seconds (J60). The implants of groups C, J30, and J60 were contaminated in vitro with oral biofilm, then groups J30 and J60 received the respective decontamination treatments. Microbiologic analysis was performed by counting the colony-forming units (CFUs), and a qualitative descriptive analysis of the implant surface was performed after microbiologic analysis using scanning electron microscopy (SEM). Statistical analysis included one-way analysis of variance (ANOVA) and Tukey tests and the independent t test, with a .05 significance level. RESULTS: There was a significant reduction (P < .01) in the number of CFUs in groups J30 (3.63 × 106 ± 0.32) and J60 (2.74 × 106 ± 0.21) compared with group C (5.05 × 106 ± 0.43). Both decontaminated groups were statistically different from group S, which did not show bacterial growth (P < .01). When groups J30 and J60 were compared, there was also a significant difference between them (P < .01), and the group J60 showed greater decontaminating potential. The descriptive qualitative analysis did not show any visible changes on the surface of the implants. CONCLUSION: The sodium bicarbonate jet was effective in decontaminating titanium implants in vitro, causing no visible damage to the implant surface.

Biological Behavior of Xenogenic Scaffolds in Alcohol-Induced Rats: Histomorphometric and Picrosirius Red Staining Analysis.

In this experimental protocol, the objective was to evaluate the biological behavior of two xenogenic scaffolds in alcohol-induced rats through histomorphometric and Picrosirius Red staining analysis of non-critical defects in the tibia of rats submitted or not to alcohol ingestion at 25% v/v. Eighty male rats were randomly divided into four groups (n = 20 each): CG/B (water diet + Bio-Oss® graft, Geistlich Pharma AG, Wolhusen, Switzerland), CG/O (water diet + OrthoGen® graft, Baumer, Mogi Mirim, Brazil), AG/B (25% v/v alcohol diet + Bio-Oss® graft), and AG/O (25% v/v alcohol diet + OrthoGen® graft). After 90 days of liquid diet, the rats were surgically obtained, with a defect in the tibia proximal epiphysis; filled in according to their respective groups; and euthanized at 10, 20, 40 and 60 days. In two initial periods (10 and 20 days), all groups presented biomaterial particles surrounded by disorganized collagen fibrils. Alcoholic animals (AG/B and AG/O) presented, in the cortical and medullary regions, a reactive tissue with inflammatory infiltrate. In 60 days, in the superficial area of the surgical cavities, particles of biomaterials were observed in all groups, with new compact bone tissue around them, without complete closure of the lesion, except in non-alcoholic animals treated with Bio-Oss® xenograft (CG/B), where the new cortical interconnected the edges of the defect. Birefringence transition was observed in the histochemical analysis of collagen fibers by Picrosirius Red, in which all groups in periods of 10 and 20 days showed red-orange birefringence, and from 40 days onwards greenish-yellow birefringence, which demonstrates the characteristic transition from the formation of thin and disorganized collagen fibers initially to more organized and thicker later. In histomorphometric analysis, at 60 days, CG/B had the highest volume density of new bone (32.9 ± 1.15) and AG/O the lowest volume density of new bone (15.32 ± 1.71). It can be concluded that the bone neoformation occurred in the defects that received the two biomaterials, in all periods, but the Bio-Oss® was superior in the results, with its groups CG/B and AG/B displaying greater bone formation (32.9 ± 1.15 and 22.74 ± 1.15, respectively) compared to the OrthoGen® CG/O and AG/O groups (20.66 ± 2.12 and 15.32 ± 1.71, respectively), and that the alcoholic diet interfered negatively in the repair process and in the percentage of new bone formed.

Preliminary Histological Evaluation of the Application of Ozone in the First Days of Orthodontic Force Induction in Animal Model.

OBJECTIVES: The aim of the study was to histologically evaluate the effect of ozone therapy on orthodontic force induction in an animal model. MATERIALS AND METHODS: Twenty-four Wistar rats were divided into three groups (n = 8). A NiTi coil spring was installed from the maxillary first molar to the maxillary central incisor. G1 was control and G2/G3 received 1 mL of ozonated gas at concentrations of 10 and 60 µg/mL, in the buccal mucosa above the first molar roots. The animals were euthanized 3 and 5 days after the procedure. Histological sections were obtained, longitudinally of the first molar' long axis, in the mesiodistal direction. The number of osteoclasts, osteoblasts, blood vessels, polymorphonuclear and mononuclear cells, formation of osteoid tissue and hyaline areas, and root resorption were evaluated with light microscope, in tension and pressure sides. Intergroup comparisons were performed with Kruskal-Wallis, Dunn, and Chi-square tests. RESULTS: At 3-days pressure side, a greater number of osteoclasts was observed in ozone groups and greater number of blood vessels and polymorphonuclear cells were observed in G2. On the tension side, there was a significantly greater number of blood vessels, osteoblasts, and mononuclear cells in G2. At 5-days pressure side, there was a significantly greater number of osteoclasts in G2, blood vessels and osteoblasts in the ozone groups, and lesser number of polymorphonuclear cells in G3. CONCLUSION: Ozone therapy increased the number of osteoclasts on the pressure side and osteoblasts on tension side, in 10 µg/mL concentration, demonstrating histological parameters favorable to bone remodeling. The 60 µg/mL ozone concentration accelerated the periodontal ligament reorganization process.

Low-Level Laser and Antimicrobial Photodynamic Therapy Reduce Peri-implantitis-related Microorganisms Grown In Vitro.

OBJECTIVE: Currently, dental implants are a predictable treatment option for oral rehabilitation; however, complications such as peri-implant diseases are increasing every day. Thus, the aim of this study was to verify the efficacy, in vitro, of two protocols against cultures of periodontal biofilm and Staphylococcus aureus. MATERIAL AND METHODS: Petri dishes for each of the following groups were used: control groups (C)-plates inoculated with periodontal biofilm (C.B; n = 4) or S. aureus (C.SA; n = 4) without any treatment; laser groups-plates inoculated with periodontal biofilm (low-level laser therapy [LLLT].B; n = 4) or S. aureus (LLLT.SA; n = 4) and treated with LLLT (660 nm, 30 mW, 50 J/cm2, and 47 seconds); antimicrobial photodynamic therapy groups (aPDT)-plates inoculated with periodontal biofilm (aPDT.B; n = 4) or S. aureus (aPDT.SA; n = 4) and treated with aPDT (red laser 660 nm, 30 mW, 50 J/cm2, 47 seconds + toluidine blue O (TBO) 100 µg/mL, and 1 minute). After treatments were performed, the contents of all plates were diluted and seeded for counting colony-forming units (CFUs). STATISTICAL ANALYSIS: Results were analyzed with one-way analysis of variance (ANOVA), Tukey's test, comparison of percentages, and independent t-tests with a 5% significance level. RESULTS: Both treatments, LLLT and aPDT, significantly reduced the number of CFUs for the two types of culture, LLLT.B (3.69 × 106 ± 0.20), aPDT.B (2.79 × 106 ± 0.13), LLLT.SA (4.10 × 106 ± 0.12), and aPDT.SA (3.23 × 106 ± 0.10) when compared with control groups C.B (5.18 × 106 ± 0.43) and C.SA (5.81 × 106 ± 0.16; p = 0.000). When treatment groups were compared separately, there was also a statistically significant difference (p = 0.000). None of the protocols were able to eliminate cultured microorganisms. CONCLUSION: The LLLT and aPDT protocols effectively reduced cultures of periodontal biofilm and S. aureus in vitro, with the superiority of aPDT.

Influence of Voxel Size on CBCT Images for Dental Implants Planning.

OBJECTIVE: This study was developed to evaluate the influence of voxel size on bone measurements for implant planning. MATERIALS AND METHODS: The research was performed by using edentulous synthetic human mandibles with different levels of bone resorption. For each mandible, height and bone thickness were measured with a digital caliper. The PaX-i3d device was used to acquire the volumes of the five mandibles, with 50kVp, 4 mA, and a voxel size of 0.08 mm. After the acquisition, the images were reconstructed in the software CS three-dimensional Imaging, with four different sizes of voxels: 0.1, 0.2, 0.3, and 0.4 mm. All volumes were analyzed by a single evaluator who performed measurements to obtain bone height and thickness, using the reference points that were considered in obtaining the gold standard. The data were analyzed by ANOVA with a significance level of 5%. RESULTS: There was no significant difference in the measurements obtained with different voxel sizes, both for bone height measurements and bone thickness. There was no statistically significant difference in measurements in thickness in comparison to the gold standard. CONCLUSION: When necessary, to measure height and bone thickness, it is possible to recommend voxel images of larger size (0.40 mm) without compromising the quality of the patient's clinical planning.

Citric acid, but not tetracycline, improves the microscopic pattern of healing of particulate autogenous bone grafts in critical-size defects.

BACKGROUND: Bone demineralization has shown to be advantageous in autogenous onlay bone grafts and in pre-osteoblasts cultures, but such procedure has never been evaluated in particulate bone grafts. This study aimed to investigate the role of two demineralizing agents in the repair of the 8-mm critical-size defects in rats' calvaria. METHODS: Eighty adult male Wistar rats were randomly assigned to one of eight groups as follows: particulate autogenous bone demineralized with citric acid for 15 seconds (CA15), 30 seconds (CA30), or 60 seconds (CA60); particulate autogenous bone demineralized with tetracycline hydrochloride for 15 seconds (TCN15), 30 seconds (TCN30), or 60 seconds (TCN60); blood clot (NC), and non-demineralized autogenous bone (PC). The calvariae were harvested at 30 and 60 postoperative days (n = 5) for blinded histological and histometric analysis of the percentage area of newly formed bone within the defects. RESULTS: In the NC and TCN groups, bone formation was limited to the margins of the defects at 30 postoperative days, whereas complete closure was present in all the specimens from CA15 group. Both at 30 and 60 postoperative days, histomorphometry showed significant higher area of newly formed bone in specimens demineralized with CA than in those demineralized with TCN or non-demineralized (P < 0.05). TCN appeared to impair bone neoformation, as its use produced similar or inferior results compared to blood clot. CONCLUSIONS: Demineralization of particulate bone grafts with CA during 15s enhanced the regeneration of critical-size defects and may be a promising adjuvant in regenerative procedures. TCN seems to be improper for this purpose.

Dental Implants Surface in vitro Decontamination Protocols.

OBJECTIVE: The number of patients rehabilitated with dental implants has contributed to increased incidence of peri-implant diseases. Due to complex and difficult treatment, peri-implantitis is a challenge and an efficient clinical protocol is not yet established. Aim of this study was to evaluate the efficacy of two protocols for in vitro decontamination of dental implants surface. MATERIALS AND METHODS: Twenty titanium implants (BioHE-Bioconect) were used. Implants were divided into five groups (n = 4). NC group (negative control): sterile implants; PC group (positive control): biofilm contaminated implants; S group: biofilm contaminated implants, brushed with sterile saline; SB group: biofilm contaminated implants, brushed with sterile saline and treated with air-powder abrasive system with sodium bicarbonate (1 minute); and antimicrobial photodynamic therapy (aPDT) group: biofilm contaminated implants, brushed with sterile saline and treated with antimicrobial photodynamic therapy (red laser + toluidine blue O). The implants were contaminated in vitro with subgingival biofilm and distributed in groups PC, S, SB, and aPDT. Each group received the respective decontamination treatment, except groups NC and PC. Then, all implants were placed in tubes containing culture medium for later sowing and counting of colony-forming units (CFUs). STATISTICAL ANALYSIS: One-way analysis of variance and Tukey tests were performed, at 5% significance level. RESULTS: Significantly fewer CFUs were observed in the aPDT group (19.38 × 105) when compared with groups SB (26.88 × 105), S (47.75 × 105), and PC (59.88 × 105) (p < 0.01). Both the aPDT and SB groups were statistically different from the NC group (p < 0.01). CONCLUSION: Proposed protocols, using air-powder abrasive system with sodium bicarbonate and aPDT, showed to be efficacious in the decontamination of dental implants surface in vitro.

Dental Care during COVID-19 Outbreak: A Web-Based Survey.

OBJECTIVE: This survey aimed to assess the effects of coronavirus disease 2019 (COVID-19) on elective and urgency/emergency dental care and dentists concerned. MATERIALS AND METHODS: A web-based survey was performed using Google forms questionnaire sent to dentists in Brazil. Questions included: personal information, type of dental care provided during quarantine, if emergencies increased, the dental office biosafety routine, among others. The levels of concern about the impact of quarantine on dental care and patient oral health conditions and the economic impact on dental practices were evaluated using a 0- to 10-point scale. Statistical analysis included descriptive, percentages, one-way ANOVA, Tukey, and chi-square tests. RESULTS: During quarantine, 64.6% of the dentists attended only urgency/emergency treatments, while 26.1% maintained routine appointments, and 9.3% closed the dental offices. A higher percentage of dentists from the least affected states continued routine dental treatment; dentists were younger and presented a significantly lower level of concern about dental treatments and oral health conditions of their patients. An increase in urgency/emergency procedures was reported by 44.1% of the dentists, mostly due to the unavailability of routine/elective dental care and increased patient anxiety and stress. The main causes of urgency/emergency appointments were toothache, dental trauma, and broken restorations, besides the breakage of orthodontic appliances and temporomandibular disorders. Dentists reported a high level of concern about the economic impact caused by quarantine. CONCLUSIONS: The pandemic/quarantine has negatively affected the clinical routine. Personal protection/hygiene care must be adopted and reinforced by dental professionals/staff to make dental procedures safer.

Association of IL16 polymorphisms with periodontitis in Brazilians: A case- control study.

Periodontitis (PD) is a chronic inflammatory process resulting from the relationship of the immune response with the components in dental plaque. Cytokines and their genetic polymorphisms seem to be involved in the immunopathogenesis of this disease. This study aimed to evaluate the correlation of IL16 polymorphism with PD. A case-control study was conducted in a sample of individuals from southern Brazil. The genotyping of IL16, rs11556218 T>G, rs4072111 C>T e rs4778889 T>C, was performed using the PCR-RFLP methodology. The serum level of IL-16 was determined using an IL-16 ELISA kit for humans. SNPStats and OpenEpi software and Wilcoxon's U test were used to perform statistical analysis. IL16 rs11556218 polymorphism was significantly associated to PD in nonsmoking patients: individuals with G/G genotype were less likely to develop PD compared to the T/T genotype (OR = 0.10; Pc = 0.019, codominant model). In addition, the TTT haplotype was associated with a high risk for PD (OR = 2.45; P = 0.01). A low IL-16 serum level was observed among individuals with PD when compared to controls (P = 0.027). Thus, the IL16 rs16556218 polymorphism and the serum levels of IL-16 were associated with periodontitis in a Brazilian sample, and this was influenced by environmental factors such as smoking.

Candida albicans-Cell Interactions Activate Innate Immune Defense in Human Palate Epithelial Primary Cells via Nitric Oxide (NO) and ß-Defensin 2 (hBD-2).

The presence of Candida albicans in the biofilm underlying the dental prosthesis is related to denture stomatitis (DS), an inflammatory reaction of the oral mucosa. The oral epithelium, a component of the innate immune response, has the ability to react to fungal invasion. In this study, we evaluated the in vitro effect of viable C. albicans on the apoptosis, nitric oxide (NO) production, and ß-defensin 2 (hBD-2) expression and production of human palate epithelial cells (HPECs). We further determined whether or not these effects were correlated with fungal invasion of epithelial cells. Interaction between HPEC primary culture and C. albicans was obtained through either direct or indirect cell-cell contact with a supernatant from a hyphal fungus. We found that the hyphae supernatants were sufficient to induce slight HPEC apoptosis, which occurred prior to the activation of the specific mechanisms of epithelial defense. The epithelial defense responses were found to occur via NO and antimicrobial peptide hBD-2 production only during direct contact between C. albicans and HPECs and coincided with the fungus's intraepithelial invasion. However, although the hBD-2 levels remained constant in the HPEC supernatants over time, the NO release and hBD-2 gene expression were reduced at a later time (10 h), indicating that the epithelial defense capacity against the fungal invasion was not maintained in later phases. This aspect of the immune response was associated with increased epithelial invasion and apoptosis maintenance.

Bone demineralization promotes superior spread of preosteoblast in culture.

Previous studies have shown substances capable of similar effects of demineralization, accelerating the process of bone remodeling. This study investigated preosteoblasts behavior in cell culture after bone demineralization with citric acid and tetracycline. Seventy-four Wistar rats provided 144 calvarial bone samples, 126 of which were randomly divided in seven groups according to the treatment given to the surface: no demineralization (C), citric acid (CA), tetracycline (TCN) during 15, 30, and 60 s. Each group received preosteoblasts cultured for 24, 48, and 72 hr. Eighteen remaining samples were analyzed for the atomic percentage (A%) by energy dispersive spectroscopy (EDS) before and after demineralization. The average percentage of bone area covered by cells increased with time and it was significantly higher after 24 and 48 hr of culture in groups CA15s, CA30s, CA60s, TCN15s, and TCN30s than in groups TCN60 and C (p < 0.05). The cell morphology in all CA and TCN groups was shown to be compatible with more advanced stages of differentiation than in C group. The A% changed after demineralization. We conclude that demineralization with citric acid or tetracycline for 15-30 s increased the area of bone surface covered by preosteoblasts. The A% changes were not sufficient to impair the cells spreading and morphology. Bone demineralization may promote potential benefits in bone regenerative procedures. HIGHLIGHTS: Low pH effects did not interfere on cell growth. Bone demineralization favored the preosteoblasts growth. A possible alternative to improve graft consolidation.

Avaliação da eficácia dos anestésicos locais articaína, bupivacaína, lidocaína e mepivacaína em cirurgias para extração de terceiros molares inferiores / Evaluation of the effectiveness of local anesthetics articaine, bupivacaine, lidocaine and mepivacaine for impacted lower third molars removal

Introdução: os procedimentos odontológicos são comumente relacionados à dor e ao desconforto. Em função disso, a maioria dos pacientes apresenta diferentes graus de ansiedade e medo que podem prejudicar a realização do tratamento. Visando controlar a dor e a ansiedade desses pacientes, cada vez mais estão surgindo estudos relacionados aos fármacos utilizados em Odontologia, dentre eles os anestésicos locais. Objetivo: comparar a eficácia dos anestésicos locais articaína, bupivacaína, lidocaína e mepivacaína em cirurgias para extração de terceiros molares inferiores de acordo com tempo de indução, tempo de duração, quantidade de tubetes ministrados e intensidade de dor pós-operatória. Métodos: foram selecionados 60 pacientes que apresentavam terceiros molares inferiores em posição simétrica com indicação para extração. Esses pacientes foram divididos em 4 grupos de 15 indivíduos. Cada grupo recebeu um dos quatro tipos de anestésicos locais de maneira aleatória. As cirurgias foram realizadas por dois cirurgiões-dentistas experientes. Os dados relacionados ao tempo de indução, quantidade de anestésico e horário do início e do término das cirurgias foram anotados, as demais informações foram relatadas pelos próprios pacientes através do preenchimento de um questionário. Resultados e Discussão: a variável "episódios de dor" não apresentou diferenças estatisticamente significantes entre os grupos. Os anestésicos articaína e bupivacaína apresentaram o menor e o maior tempo de indução, respectivamente. A articaína foi o anestésico local que necessitou do menor número de tubetes para realização das cirurgias, enquanto que a bupivacaína foi o anestésico que precisou de mais tubetes. A bupivacaína também foi o anestésico local que apresentou maior tempo de duração da anestesia, seguido pela articaína, lidocaína e mepivacaína, respectivamente. A variável "intensidade de dor pós-operatória" não apresentou diferenças estatisticamente significantes. Conclusão: concluiu-se que os episódios de dor pós-operatória podem não estar relacionados ao anestésico local utilizado e que, no conjunto dos parâmetros avaliados, a articaína parece ser o anestésico local que apresenta mais vantagens na realização de cirurgias de extração de terceiros molares inferiores.

Introduction: dental procedures are commonly related to pain and discomfort leading most patients to have different degrees of anxiety and fear that may impair the performance of treatment. Aiming to control the pain and anxiety of these patients, more and more studies are being developed related to drugs used in Dentistry, among them local anesthetics. Objective: to compare the effectiveness of local anesthetics Articaine, Bupivacaine, Lidocaine and Mepivacaine for lower third molar removal according to: time to onset, period of duration of the anesthesia, number of cartridges and intensity of postoperative pain. Methods: sixty patients underwent removal of symmetrically positioned lower third molars in accordance to the classifications of Winter and Pell and Gregory, through panoramic radiographs. The patients were divided into 4 groups of 15 patients. Each group received randomized one of the four types of local anesthetics. The surgeries were realized by two oral and maxillofacial surgeons. The data related to time to onset, number of cartridges and time of the beginning and end of the surgeries were written down. Additional information was reported by the patients through a questionnaire. Results: The variable "pain" did not present statistically significant differences among the groups. Articaine and bupivacaine presented the shortest and the longest time to onset, respectively. Articaine was the local anesthetic which employed the smallest number of cartridges, considering that bupivacaine employed the highest number of cartridges. Bupivacaine presented the longest period of anesthesia, followed by articaine, lidocaine and mepivacaine. The parameter "intensity of postoperative pain" did not present statistically significant differences. Conclusions: according to the analyzed parameters we conclude that postoperative pain does not depend on the local anesthetics employed; Bupivacaine is the local anesthetic with the longest period of anesthesia; Articaine is the most indicated anesthetic for this type of procedure.

Recobrimento radicular empregando ativação do periósteo em recessão gengival ampla / Surgical coverage of wide gingival recession using periosteal activation

A recessão gengival caracteriza-se pela migração apical da margem da gengiva, expondo a superfície radicular. Esta condição pode acarretar o desenvolvimento de hiperestesia dentinária, lesões cariosas e/ou comprometimento da estética. O tratamento por cirurgias de recobrimento radicular nem sempre é previsível, especialmente em recessões amplas e profundas, e o deslize lateral do retalho é uma das técnicas que pode ser ou não associada ao enxerto de conjuntivo subepitelial. A ativação do periósteo previamente a essa cirurgia não tem sido muito explorada nas publicações, embora exista há quase 40 anos. Este relato clínico demonstra a associação da técnica do deslize lateral do retalho à ativação do periósteo para recobrimento radicular de recessão ampla classe II de Miller, cuja queixa principal era insatisfação estética e sensibilidade dentinária. O conhecimento biológico e a correta realização da técnica, associados à eliminação do agente etiológico e rigoroso acompanhamento pós-cirúrgico, resultaram no sucesso do tratamento, como atestado pelo controle de um ano e cinco meses.

Gingival recession is characterized by the apical migration of the gingival margin that exposes the dental root surface. This condition can lead to the development of dentinal hyperesthesia, carious lesions and/or aesthetic impairment. The surgical treatment for root coverage not always provides predictable results, especially in wide and deep recessions. The horizontal sliding flap associated or not to subepithelial conjunctive grafts is a commonly employed technique, but periosteal activation prior to surgery has not been much explored in the literature, although it has existed for almost 40 years. This clinical case reports the association of horizontal sliding fl ap with the activation of the periosteum to recover a wide Miller class II recession in a patient complaining of poor aesthetic and dentin sensitivity. The biological knowledge applied to a skillful technique, associated to the elimination of the etiologic agent and rigorous post-surgical follow-up provided a succesful outcome after 1 year and 5 month observations.

In vitro evaluation of adhesion/proliferation of human gingival fibroblasts on demineralized root surfaces by toluidine blue O in antimicrobial photodynamic therapy.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) in Dentistry has important effects as bacterial destruction in areas with periodontal disease. Some dyes applied in aPDT could present low pH and, consequently, result in tooth demineralization. This study evaluated demineralization produced by aPDT with toluidine blue O (TBO) at low pH and analyzed adhesion/proliferation of human gingival fibroblasts (HGF). METHODS: In the 1st phase, bovine enamel and root dentin fragments received 2 treatments: PDT4 group (TBO-100 µg/ml-pH 4-60s) plus laser (660 nm, 45 J/cm(2), 1.08 J, 30 mW, 30 s, spot 0.024 cm(2), 1.25 W/cm(2), sweeping, non-contact) and CA group (citric acid plus tetracycline-pH 1-180 s). Surface hardness loss and tooth wear were statistically analyzed (Student's t test, ANOVA/Tukey, p<0.05). In the 2nd phase, human dentin fragments were divided in C (control group-scaling and root planing), PDT4 and CA. HGF (10(4), 5th passage) were cultured on these fragments for 24, 48 and 72 h and counted in scanning electron microscopy photographs. Number of HGF was analyzed using repeated-measures ANOVA and Tukey (p<0.05). RESULTS: Percentage of surface hardness loss was similar in dentin for PDT4 (71.5%) and CA (76.1%) (p>0.05) and higher in enamel for CA (68.0%) compared to PDT4 (34.1%) (p<0.05). In respect to wear, no difference was found between PDT4 (dentin: 12.58 µm, enamel: 12.19 µm respectively) and CA (dentin: 11.74 µm and enamel: 11.03 µm) (p>0.05). Number of HGF was higher after 72 h in CA group (2.66, p<0.05) compared to PDT4 (2.2) and C (1.33). CONCLUSION: PDT4 is not as aggressive as CA for enamel. However, dentin demineralized promoted by PDT4 does not stimulate HGF adhesion and proliferation as CA.

Bone demineralization with citric acid enhances adhesion and spreading of preosteoblasts.

BACKGROUND: Previous studies have demonstrated that bone demineralization can improve consolidation in bone grafts. The biologic mechanisms underlying this phenomenon remain unclear. METHODS: Twelve adult male guinea pigs were used in this experiment. Forty-five bone samples removed from the calvaria of nine animals were divided in groups (n = 9) according to the time of demineralization with citric acid (50%, pH 1): 15, 30, 90, and 180 seconds and non-demineralized samples (control). Preosteoblasts (MC3T3-E1) were cultured on the bone samples for 24, 48, and 72 hours (n = 3). Fifteen samples removed from the remaining three animals were analyzed by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) after demineralization (n = 3). RESULTS: The number of preosteoblasts increased significantly with time in all groups. The bone surface area covered by these cells increased with time, except in the control group. Intragroup differences occurred between 24 and 72 hours (P < 0.05). Samples demineralized for 30 seconds showed greater area covered by preosteoblast cells than for the other times of demineralization in all periods of cell culture (P < 0.05) without a statistically significant difference compared with 15 seconds. SEM/EDS showed diminished content of calcium (Ca) after 15 seconds of demineralization, but the Ca content increased after 180 seconds of demineralization (P < 0.05). The phosphorus (P) amount increased significantly only after 30 seconds of demineralization (P < 0.5). The sulfur (S) content was increased in demineralized samples in relation to non-demineralized ones, reaching the highest level after 90 seconds, when the difference became significant in relation to all the other times of demineralization (P < 0.05). Magnesium (Mg) content did not differ significantly between demineralized and non-demineralized samples. CONCLUSIONS: Bone surfaces demineralized for 30 seconds increased the spreading of preosteoblasts as well as the surface area covered by these cells. Bone demineralization deserves to be studied in periodontal and maxillofacial regenerative procedures.

Efeito da desmineralização óssea sobre parâmetros de superfície e sobre o comportamento de pré-osteoblastos em cultura: estudo em microscopia eletrônica de varredura e confocal / Effect of bone demineralization on surface parameters and on behavior of pre-osteoblasts in culture: study in scanning electron microscopy and confocal microscopy

A desmineralização óssea superficial tem se demonstrado favorável à consolidação de enxertos e ao comportamento celular, entretanto os mecanismos envolvidos ainda não estão esclarecidos. Os subsídios para o embasamento biológico da desmineralização, proporcionado por publicações anteriores, sugeriram que modificações na superfície óssea teriam influenciado o comportamento de pré-osteoblastos em cultura. Assim, este estudo objetivou comparar o efeito de duas concentrações de ácido cítrico na desmineralização de superfícies ósseas onde foram cultivadas células pré-osteoblásticas (MC3T3-E1), e analisar parâmetros de superfície comparando superfícies desmineralizadas a não desmineralizadas. Setenta amostras ósseas bicorticais foram removidas das calvárias de 35 ratos e divididas em grupos para as análises: 1) Microscopia Eletrônica de Varredura (MEV) para avaliação da área de recobrimento e espessura da camada de células sobre as amostras (n = 15) durante 24, 48 e 72 horas: Grupo AC.10 – amostras desmineralizadas por 30 segundos com ácido cítrico 10 %; Grupo AC.50 –amostras desmineralizadas por 30 segundos com ácido cítrico 50 %; e Grupo C (controle) – amostras não desmineralizadas; 2) Microscopia Confocal para análise da área de expressão e intensidade de fluorescência das BMP-2, -4 e -7: AC.10 – seis amostras desmineralizadas conforme item 1); AC.50 – seis amostras desmineralizadas conforme item 1); C – três amostras não desmineralizadas; 3) Microscopia Confocal para análise da rugosidade superficial média (Ra e Sa): Grupos AC.10 e AC.50 com cinco amostras cada, desmineralizadas conforme o item 1), sendo cada amostra seu próprio controle (análises antes e depois da desmineralização). Também foram avaliadas as distâncias entre picos (P-P) e entre picos e vales (P-V) antes e depois da desmineralização; 4) Microscopia Eletrônica de Varredura / Espectroscopia de Energia Dispersiva (MEV / EDS) para análise da composição superficial: mesmas...

The superficial bone demineralization has proved to be a favorable procedure for bone grafts consolidation and cell behavior, however the underlying mechanisms have not been clarified yet. Therefore, this study aimed to compare the effect of two concentrations of citric acid on demineralization of bone surfaces where pre-osteoblastic cells (MC3T3-E1) were cultivated, and analyze surface parameters comparing demineralized bone surfaces with non-demineralized surfaces. Seventy bicortical bone samples were harvested from the calvaria of 35 rats and divided into groups as follows: 1) Scanning Electron Microscopy (SEM) to evaluate the coating area and thickness of cells layers cultured on the samples (n = 15) for 24, 48, and 72 hours: Group CA.10 – samples demineralized for 30 seconds with 10 % citric acid; Group CA.50 – samples demineralized for 30 seconds with 50 % citric acid, and Group C (control) – non-demineralized samples; 2) Confocal Microscopy for analysis of expression area and intensity of fluorescence of BMP-2, -4, and -7: CA.10 – six samples demineralized as item 1); CA.50 – six samples demineralized as item 1); Group C – three non-demineralized samples; 3) Confocal Microscopy for surface mean roughness analysis (Ra and Sa): Groups CA.10 and CA.50 made up of five samples each and demineralized according to item 1), each sample was its own control (analysis before and after demineralization). The distances between peaks (P-P) and between peaks and valleys (P-V) were also evaluated before and after demineralization; 4) Scanning Electron Microscopy / Energy Dispersive Spectroscopy (SEM / EDS) to analyze the surface composition: the same samples of item 3) were evaluated before and after demineralization for atomic percentage (%A) of carbon, oxygen, magnesium, phosphorus, sulfur and calcium. Statistical test was made by adopting the 95 % significance level. Demineralized samples showed cells with morphology in the later stages of differentiation...