New insights into a poorly known parasite, Dero lutzi (Oligochaeta: Naididae), associated with tree frogs of the genus Scinax: morphological evaluation and genotypic data.

The oligochaete Dero lutzi follows a life strategy that alternates between free-living periods in aquatic environments and endoparasitic phases. Most occurrences of D. lutzi in anurans are reported in species with arboreal habits, with studies limited to the recording of the oligochaete's presence in the host. Our study recovered specimens of D. lutzi from the tree frogs Scinax fuscovarius and Scinax. nasicus. We performed a morphological assessment of the parasite using light microscopy, for the first time, scanning electron microscopy. Molecular characterization of D. lutzi was carried out using the mitochondrial gene 16S rRNA and the nuclear gene 28S rRNA. Additionally, a phylogenetic tree was constructed to assess the species´position in relation to other group members. In our results, we confirmed the phenotypic morphological characteristics of the endoparasitic phase of D. lutzi. We also presented its phylogenetic position with other oligochaetes in the group, demonstrating the proximity between the endoparasite D. lutzi and the free-living oligochaete D. superterrenus.

Insulin Therapy on Bone Macroscopic, Microarchitecture, and Mechanical Properties of Tibia in Diabetic Rats.

BACKGROUND: This study evaluated tibia's macroscopic structure, mechanical properties, and bone microarchitecture in rats with type 1 diabetes mellitus (T1DM). METHODS: Eighteen animals were divided into three groups (n=6): non-diabetic (ND), diabetic (D), and diabetic+insulin (DI). T1DM was induced by streptozotocin; insulin was administered daily (4IU). The animals were euthanized 35 days after induction. The tibiae were removed and analyzed using macroscopic, micro-computed tomography (micro-CT) and three-point bending. The macroscopic analysis measured proximal-distal length (PD), antero-posterior thickness (AP) of proximal (AP-P) and distal (AP-D) epiphysis, and lateral-medial thickness (LM) of proximal (LM-P) and distal (LM-D) epiphysis. Micro-CT analysis closed porosity, tissue mineral density, and cortical thickness. The three-point bending test measured maximum strength, energy, and stiffness. RESULTS: The macroscopic analysis showed that D presented smaller measures of length and thickness (AP and AP-P) than ND and DI. More extensive measurements were observed of LM and AP-D thickness in DI than in D. In micro-CT, DI showed larger cortical thickness than D. Mechanical analysis showed lower strength in D than in other groups. CONCLUSIONS: T1DM reduces bone growth and mechanical strength. Insulin therapy in diabetic rats improved bone growth and fracture resistance, making diabetic bone similar to normoglycemic animals.

Histomorphometric comparison of two different preclinical models to evaluate the bone repair in grafted areas

Aim: This study was performed to compare two different rat defect models (critical calvaria defects versus guided bone regeneration in the mandibular ramus) used to evaluate bone repair in grafted areas. Methods: A total of 12 rats were allocated in two groups according the experimental model used to evaluate the bone repair in grafted areas: a critical sized-calvaria defect of 5 mm filled with bone graft (n=6) and a mandibular ramus filled with the bone graft associated with a Teflon dome-shaped membrane (n=6). Both groups were grafted with deproteinized bovine bone graft. After 60 days, the animals were euthanized and the samples obtained were submitted to histomorphometry analysis to evaluate the relative amount of bone, remaining bone substitute, and soft tissue within the grafted areas. Results: No differences were observed between the preclinical models evaluated in relation to the amount of bone tissue formation (19.93 ± 4.55% in calvaria vs. 21.00 ± 8.20% in mandible). However, there was a smaller amount of soft tissue (43.20 ± 10.97% vs. 57.79 ± 7.61 %; p<0.01) and a greater amount of bone substitute remaining (35.80 ± 5.52% vs. 22.28 ± 4.36 %; p<0.05) in the grafted areas in the mandible compared to calvaria defect. Conclusion: Preclinical models for the analysis of bone repair in grafted areas in the mandible and critical sized-calvaria defects showed different responses in relation to the amount of soft tissue and bone substitute remnants

Assessment of the nursing staff's knowledge on periodontal disease and its associations with systemic changes / Avaliação do conhecimento da equipe de enfermagem sobre doença periodontal e suas associações com alterações sistêmicas

Abstract Introduction The maintenance of oral health in inpatients is essential, particularly to avoid complications arising from periodontal disease, which not only affect oral health but can also exacerbate systemic issues during hospitalization. Objective: This study aimed to assess nursing staff's knowledge regarding the management of periodontal disease and its association with systemic diseases. Material and method This cross-sectional observational study was conducted in a general referral hospital of the Brazilian National Health System (SUS). A total of 504 nursing professionals completed a self-administered 24-item questionnaire on relating to oral care procedures and the importance of oral health in hospitalized patients. Data were analyzed using descriptive analysis and the chi-squared test (α = 0.05). Result Most respondents (97.8%) believed that oral infections can affect a patient's general health and that oral hygiene is important during hospitalization. However, knowledge deficits were identified. The oral effect of periodontal disease was considered moderate by 49.3% of the participants, and 74.6% believed that sugar was the most common cause of periodontal disease. Conclusion Nursing professionals are aware of the importance of maintaining oral hygiene and the relationship between periodontal and systemic diseases. However, their dental hygiene practice knowledge is limited. A training program on oral healthcare for inpatients and the inclusion of oral hygiene topics in the curricula of nursing professionals are recommended.

Resumo Introdução A manutenção da saúde bucal em pacientes internados é essencial, especialmente para evitar complicações decorrentes da doença periodontal, que não apenas afetam a saúde bucal, mas também podem agravar problemas sistêmicos durante a hospitalização. Objetivo: Este estudo teve como objetivo avaliar o conhecimento da equipe de enfermagem em relação ao manejo da doença periodontal e sua associação com doenças sistêmicas. Material e método Este estudo observacional transversal foi conduzido em um hospital geral de referência do Sistema Único de Saúde (SUS) do Brasil. Um total de 504 profissionais de enfermagem completaram um questionário autoaplicável com 24 questões, abordando procedimentos de cuidados bucais e a importância da saúde bucal em pacientes hospitalizados. Os dados foram analisados por meio de análise descritiva e teste qui-quadrado (α = 0,05). Resultado A maioria dos entrevistados (97,8%) acreditava que infecções bucais podem afetar a saúde geral do paciente e que a higiene bucal é importante durante a hospitalização. No entanto, foram identificados déficits de conhecimento. O efeito oral da doença periodontal foi considerado moderado por 49,3% dos participantes, e 74,6% acreditavam que o açúcar era a causa mais comum da doença periodontal. Conclusão Profissionais de enfermagem reconhecem a importância da manutenção da higiene bucal e a relação entre doença periodontal e doenças sistêmicas. No entanto, seu conhecimento prático em higiene bucal é limitado. Recomenda-se um programa de treinamento em cuidados bucais para pacientes internados e a inclusão de tópicos de higiene bucal nos currículos dos profissionais de enfermagem.

Effect of micro-CT acquisition parameters and individual analysis on the assessment of bone repair.

This study aimed to investigate whether two acquisition parameters, voxel size and filter thickness, used in a micro-computed tomography (micro-CT) scan, together with the examiner's experience, influence the outcome of bone repair analysis in an experimental model. Bone defects were created in rat tibiae and scanned using two voxel sizes of 6- or 12-µm and two aluminum filter thickness of 0.5- or 1-mm. Then, bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) were analyzed twice by two groups of operators: experienced and inexperienced examiners. For BV/TV, no significant differences were found between scanning voxel sizes of 6 and 12 µm for the experienced examiners; however, for the inexperienced examiners, the analysis performed using a 12-µm voxel size resulted in higher BV/TV values (32.4 and 32.9) than those acquired using a 6-µm voxel size (25.4 and 24.8) (p < 0.05). For Tb.Th, no significant differences between the analyses performed by experienced and inexperienced groups were observed when using the 6-µm voxel size. However, inexperienced examiners' analysis revealed higher Tb.Th values when using the 12-µm voxel size compared with 6 µm (0.05 vs. 0.03, p < 0.05). Filter thickness had no influence on the results of any group. In conclusion, voxel size and operator experience affected the measured Tb.Th and BV/TV of a region with new bone formation. Operator experience in micro-CT analysis is more critical for BV/TV than for Tb.Th, whereas voxel size significantly affects Tb.Th evaluation. Operators in the initial phases of research training should be calibrated for bone assessments.

Effect of different materials for conventional and 3D-printed models on the mechanical properties of ethylene-vinyl acetate utilized for fabricating custom-fit mouthguards.

BACKGROUND/AIM: The interaction between the ethylene-vinyl acetate (EVA) with distinct materials utilized for obtaining dental models can affect the performance of resulting mouthguards. This study attempted to evaluate the effect of different materials for conventional (dental stone) or 3D-printed (resin) models on EVA's physical and mechanical properties and surface characteristics. MATERIAL AND METHODS: EVA sheets (Bioart) were laminated over four model types: GIV, conventional Type IV dental stone model (Zhermak); ReG, resin-reinforced Type IV dental stone model (Zero Stone); 3DnT, 3D resin printed model (Anycubic) without surface treatment; 3DT, 3D-printed model (Anycubic) with water-soluble gel (KY Jelly Lubricant, Johnson & Johnson) coating during post-curing process. The EVA specimens were cut following the ISO 37-II standard (n = 30). Shore A hardness was measured before and after plasticization on the contact (internal) or opposite (external) surfaces with the model. The breaking force (F, N), elongation (EL, mm), and ultimate tensile strength (UTS, MPa) were measured using a universal testing machine. Macro-photography and scanning electron microscopy were adopted for classifying the EVA surface alteration. Data were analyzed by one-way ANOVA with repeated measures, followed by Tukey's test (α = .05). RESULTS: Plasticization significantly decreased Shore A values for the tested EVA regardless of the model type (p < .001). Higher F, El, and UTS values were verified for the EVA with 3DT and GIV models compared to ReG and 3DnT (p < .001). 3DnT models resulted in severe surface alteration and a greater reduction of the mechanical properties of the EVA. CONCLUSION: The interaction of EVA with 3D resin-printed models without surface treatment or resin-reinforced Type IV dental stone models significantly affected the physical and mechanical properties of this material. The utilization of water-soluble gel coating during the post-curing process of 3D resin printed models improved the mechanical properties of the EVA, similarly when this material was plasticized over conventional Type IV dental stone model.

Effects of different doses of ionizing radiation on alveolar bone repair in post-extraction tooth socket: an experimental study in rats.

OBJECTIVE: This study aimed to evaluate the dose-response effects of ionizing radiation (IR) on alveolar bone repair and bone strength after tooth extraction. MATERIALS AND METHODS: A total of 32 male Wistar rats were used in the study, 28 animals were included in the final analysis, and n = 7 for each experimental group. Mandibular first molars were extracted. After 7 days, the animals were randomly divided into four groups according to single-dose irradiation: NIr, control group; Ir15, irradiated at 15 Gy; Ir20, irradiated at 20 Gy; and Ir30, irradiated at 30 Gy. The tooth extraction sites were subjected to micro-computed tomography (micro-CT), histological, histomorphometric, and biomechanical analyses 14 days after extraction. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test (α = 0.05). RESULTS: Micro-CT analysis revealed that IR led to lower values of bone volume (BV, in mm3) (0.68 ± 0.08, P < 0.001) and bone volume fraction, ratio of the segmented bone volume to the total volume of the region of interest (BV/TV, in %) (44.1 ± 8.3, P < 0.001) for the Ir30 group compared to the control group. A significantly lower amount of newly formed bone was observed in the Ir30 (P = 0.005) than in the Ir15 group. The histomorphometric results of quantification of bone matrix neoformation and the micro-CT were in agreement, demonstrating greater damage to the Ir30 group. IR30 cells showed a lower percentage of densely packed collagen than control cells. No significant differences were found in the biomechanical parameters. CONCLUSION: IR affects alveolar bone repair. A dose of 30 Gy reduced the bone healing process owing to a smaller amount of newly formed bone and a lower percentage of densely packed collagen. Therefore, a dose of 30 Gy can be used to successfully establish an animal model of an irradiated mandible that mimics the irradiated clinical conditions. CLINICAL RELEVANCE: Radiotherapy can lead to severe side effects and tooth extraction is a major risk factor. A proper understanding of the pathological mechanisms of radiation in alveolar bone repair requires the establishment of a suitable animal model of clinical conditions.

Root coverage with platelet-rich fibrin or connective tissue graft: a split-mouth randomized trial.

This study aimed to compare the use of connective tissue grafts (CTG) and platelet-rich fibrin (PRF) associated with the tunnel technique (TT) for the treatment of multiple gingival recessions (GR). Fourteen patients with multiple bilateral GR [type 1 recession (RT 1)] in the maxillary incisors, canines, and/or premolars were included. The TT was performed on both sides (split-mouth model); CTG (36 GR) was used on one side, and on the other, PRF (36 GR) was used. Clinical parameters, including recession depth (RD), probing depth, clinical attachment level (CAL), and keratinized gingiva thickness/width (GT/KTW), were obtained at baseline and after 1, 3, 6, and 16 months. Lower RD (0.81 ± 0.68 vs. 1.23 ± 0.71 mm) and CAL (2.54 ± 0.63 vs. 2.73 ± 0.82 mm) were observed for CTG compared to PRF after 16 months. Higher GT was obtained for CTG compared to PRF after 3 (1.81 ± 0.56 vs 1.43 ± 0.47 mm) and 6 months (1.67 ± 0.61 vs. 1.38 ± 0.55 mm, p < 0.05). The recession coverage (RC) was higher for CTG (55.42% ± 37.14) in comparison to PRF (29.53% ± 34.08) after 16 months (p < 0.05). Similarly, CTG presented a more complete coverage of the recession (15; 41.66%) than PRF (9; 24.32%). There were no significant differences between the groups in terms of surgery time, postoperative pain, or healing patterns. Greater esthetic satisfaction was obtained with CTG. It was concluded that CTG combined with TT showed clinical and esthetic results superior to those of PRF in multiple GR treatments.

Fluorescence-aided identification technique using a low-cost violet flashlight and rotatory instruments for dental trauma splint removal.

BACKGROUND/AIM: Removing resin composites used for bonding dental trauma splints may result in irreversible damage to the enamel. This in vitro study evaluated the influence of additional violet illumination and different bur types on damage caused to tooth enamel. MATERIALS AND METHODS: Fifteen maxillary models with four bovine incisor teeth were prepared. All models were scanned using a laboratory scanning system (s600 ARTI; Zirkonzahn). Six experimental groups (n = 10) were generated by two study factors: lighting type (three levels), (1) low-cost (5-7 US$) violet LED flashlight (LUATEK, LT 408); (2) VALO Cordless light curing unit (Ultradent) with black lens; or (3) without additional illumination; and rotatory instrument (two levels), (1) diamond bur or (2) multifluted tungsten-carbide bur. New scanning was performed after splint removal, and the generated files were superimposed on the initial scans using Cumulus software. The light emitted by both violet light sources was characterized by using integrating sphere and beam profile. A qualitative and quantitative analysis of enamel damage and two-way ANOVA followed by Tukey's post hoc was used at an α = 0.05. RESULTS: The use of low-cost violet flashlight that emitted the violet peak light at 385 nm and VALO Cordless with black lens at 396 nm resulted in significantly lower damage to the enamel surface than those in the groups without additional violet light (p < .001). An interaction between rotatory instruments and lighting was found. When no additional violet lighting was used, the diamond bur presented higher mean and maximum depth values. CONCLUSIONS: Fluorescence lighting facilitated the removal of remnant resin composite dental trauma splints, leading to less invasive treatment. The diamond bur resulted in higher enamel damage than that affected by the multifluted bur when no violet lighting was used. A low-cost violet flashlight is a useful fluorescence-aided identification technique for removing resin composite dental trauma splints.

Biomechanical effects of a hard insert and air space in mouthguards on the shock absorption and protection against fractures of direct resin composite veneers from trauma.

BACKGROUND/AIM: Mouthguards (MTG) are used to prevent dental trauma. However, their protective effect on esthetic restorations and whether modified MTGs are beneficial is uncertain. The aim of this study was to evaluate the effect of hard inserts and air spaces in MTGs in protecting direct resin composite veneers during impact. MATERIALS AND METHODS: Twenty resin composite veneers (1.0 mm) were prepared on upper right central incisors on printed maxilla models using polyether. The effect of the MTGs was evaluated in four groups (n = 5): Con-MTG, conventional custom-fit MTGs made with two layers of ethylene vinyl acetate (EVA); Air-MTG, MTGs with the insertion of 2.0 mm air space between the two layers of EVA and tooth surface; PETG-MTG, MTGs with 1.0 mm of polyethylene terephthalate glycol-modified (PETG) inserted between the EVA layers; and No-MTG, comprising resin composite veneers without MTG. The printed models were fixed in a pendulum device, and the impact was performed at 30°. The strain (µS) and shock absorption (%) of the MTG were recorded using strain gauges. Failure modes and cracks were evaluated using macro photography and transillumination and analyzed using the chi-square test. Strain and shock absorption data were analyzed using the one-way analysis of variance followed by Tukey's test (α = 0.05). RESULTS: Mouthguards reduced strain and enhanced shock absorption, regardless of the MTG type (p < .001). Con-MTG, Air-MTG, and PETG-MTG had shock absorption rates of 76.1%, 72.3%, and 33.4%, respectively (p < .001). The single No-MTG model had a root fracture, while all the others had superficial damage. None of the MTG models had cracks or fractures. CONCLUSIONS: Mouthguards protected the resin composite veneers. The Con-MTG and Air-MTG groups had lower strain and greater shock absorption than the PETG-MTG. Resin veneers had no cracks or damage following MTG use. However, 80% of the veneers had surface damage when no MTG was used.

Advanced platelet-rich-fibrin (A-PRF +) has no additional effect on the healing of post-extraction sockets of upper third molars. A split mouth randomized clinical trial.

PURPOSE: This study evaluated the effects of advanced platelet-rich fibrin (A-PRF +) on the healing of upper third molar post-extraction sockets. METHODS: Sixteen patients who underwent extractions of the upper third molars (18 and 28) were included in this randomized split-mouth study. The alveoli on the test side were filled with A-PRF + , while the control side was maintained with blood clot. The side that received treatment was randomly defined. Alveolar bone regeneration was evaluated by CBCT scans to assess healing stage, bone density, and fractal analysis 1 week and 90 days post-extraction. Additionally, pain, edema, bleeding, and soft tissue alveolar repair were evaluated by clinical analyses 3, 7, 14, 30, and 90 days after the surgical procedure using a visual analog scale. RESULTS: There were no clinical differences regarding treatments in any experimental period. In the tomographic evaluation, at 7 days, the alveoli treated with A-PRF + presented a suggestive sign of higher bone density than the control alveoli, which was not confirmed 90 days after the surgical procedure. CONCLUSION: Thus, the use of A-PRF + does not demonstrate a clinical advantage in the repair of post-extraction sockets of upper third molars.

Definition of the Region of Interest for the Assessment of Alveolar Bone Repair Using Micro-computed Tomography.

The objective of this study was to evaluate the influence of the extraction socket (distal or lingual root) and the type of region of interest (ROI) definition (manual or predefined) on the assessment of alveolar repair following tooth extraction using micro-computed tomography (micro-CT). The software package used for scanning, reconstruction, reorientation, and analysis of images (NRecon®, DataViewer®, CT-Analyzer®) was acquired through Bruker < https://www.bruker.com > . The sample comprised the micro-CT volumes of seven Wistar rat mandibles, in which the right first molar was extracted. The reconstructed images were analyzed using the extraction sockets, i.e., the distal and intermediate lingual root and the method of ROI definition: manual (MA), central round (CR), and peripheral round (PR). The bone volume fraction (BV/TV) values obtained were analyzed by two-way ANOVA with Tukey's post hoc test (α = 5%). The distal extraction socket resulted in significantly lower BV/TV values than the intermediate lingual socket for MA (P = 0.001), CR (P < 0.001), and PR (P < 0.001). Regarding the ROI, when evaluating the distal extraction socket, the BV/TV was significantly higher (P < 0.001) for MA than for CR and PR, with a lower BV/TV for CR. However, no significant difference was observed for MA (P = 0.855), CR (P = 0.769), or PR (P = 0.453) in the intermediate lingual extraction socket. The bone neoformation outcome (BV/TV) for alveolar bone repair after tooth extraction is significantly influenced by the ROI and the extraction socket. Using the predefined method with a standardized ROI in the central region of the distal extraction socket resulted in the assessment of bone volume, demonstrating the most critical region of the bone neoformation process.

Effect of micro-CT acquisition parameters and individual analysis on the assessment of bone repair

Abstract This study aimed to investigate whether two acquisition parameters, voxel size and filter thickness, used in a micro-computed tomography (micro-CT) scan, together with the examiner's experience, influence the outcome of bone repair analysis in an experimental model. Bone defects were created in rat tibiae and scanned using two voxel sizes of 6- or 12-µm and two aluminum filter thickness of 0.5- or 1-mm. Then, bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) were analyzed twice by two groups of operators: experienced and inexperienced examiners. For BV/TV, no significant differences were found between scanning voxel sizes of 6 and 12 µm for the experienced examiners; however, for the inexperienced examiners, the analysis performed using a 12-µm voxel size resulted in higher BV/TV values (32.4 and 32.9) than those acquired using a 6-µm voxel size (25.4 and 24.8) (p < 0.05). For Tb.Th, no significant differences between the analyses performed by experienced and inexperienced groups were observed when using the 6-µm voxel size. However, inexperienced examiners' analysis revealed higher Tb.Th values when using the 12-µm voxel size compared with 6 µm (0.05 vs. 0.03, p < 0.05). Filter thickness had no influence on the results of any group. In conclusion, voxel size and operator experience affected the measured Tb.Th and BV/TV of a region with new bone formation. Operator experience in micro-CT analysis is more critical for BV/TV than for Tb.Th, whereas voxel size significantly affects Tb.Th evaluation. Operators in the initial phases of research training should be calibrated for bone assessments.

Clinical dental management of the head and neck irradiated patient: topics of interest for clinicians

To discuss important topics regarding the dental procedures performed in patients before, during and after the radiotherapy treatment. The biological effects of ionizing radiation on bone tissue focusing on clinical care will be described. The invasive and not invasive procedures after radiotherapy treatment in the head and neck region will be addressed using scientific evidences to determine the appropriate moment for tooth extractions, periodontal management, and preventive procedures for osteoradionecrosis. Methods: Thirty-three studies including original studies and reviews were selected in MEDLINE database (PubMed). No year of publication restriction was applied. Language was restricted to the English, and the following Medical Subject Heading terms were used: radiotherapy, osteoradionecrosis, dental management. Studies of osteoradionecrosis involving clinical management of irradiated patients, with an emphasis on updated guidelines and protocols were selected. Results: Care in dental procedures were related about restorative treatment, endodontic treatment, rehabilitation for edentulous regions using prostheses and implants and periodontal procedures before, during and after RTX treatment. Conclusions: The dental procedures should and can be performed before, during but also after radiotherapy. However, the clinical procedures should be less invasive as possible. A maintenance plan that reduces the necessity for major and more invasive treatments after radiotherapy is recommended

Root coverage with platelet-rich fibrin or connective tissue graft: a split-mouth randomized trial

Abstract: This study aimed to compare the use of connective tissue grafts (CTG) and platelet-rich fibrin (PRF) associated with the tunnel technique (TT) for the treatment of multiple gingival recessions (GR). Fourteen patients with multiple bilateral GR [type 1 recession (RT 1)] in the maxillary incisors, canines, and/or premolars were included. The TT was performed on both sides (split-mouth model); CTG (36 GR) was used on one side, and on the other, PRF (36 GR) was used. Clinical parameters, including recession depth (RD), probing depth, clinical attachment level (CAL), and keratinized gingiva thickness/width (GT/KTW), were obtained at baseline and after 1, 3, 6, and 16 months. Lower RD (0.81 ± 0.68 vs. 1.23 ± 0.71 mm) and CAL (2.54 ± 0.63 vs. 2.73 ± 0.82 mm) were observed for CTG compared to PRF after 16 months. Higher GT was obtained for CTG compared to PRF after 3 (1.81 ± 0.56 vs 1.43 ± 0.47 mm) and 6 months (1.67 ± 0.61 vs. 1.38 ± 0.55 mm, p < 0.05). The recession coverage (RC) was higher for CTG (55.42% ± 37.14) in comparison to PRF (29.53% ± 34.08) after 16 months (p < 0.05). Similarly, CTG presented a more complete coverage of the recession (15; 41.66%) than PRF (9; 24.32%). There were no significant differences between the groups in terms of surgery time, postoperative pain, or healing patterns. Greater esthetic satisfaction was obtained with CTG. It was concluded that CTG combined with TT showed clinical and esthetic results superior to those of PRF in multiple GR treatments.

Use of platelet-rich fibrin for bone repair: a systematic review and meta-analysis of preclinical studies.

This systematic review evaluated the potential utility of platelet-rich fibrin (PRF) in bone repair in animals. The question is: can the use of PRF in bone defects in healthy rats induce bone repair compared to clot? This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (Prisma). The protocol was registered with Prospero (CRD [42020162319]). The literature search involved nine databases, including grey literature. All studies evaluated the bone defects created in rats filled with PRF and clots (control). Biomaterial evaluation was also performed in this study. The risk of bias was assessed using the Systematic Review Center for Laboratory Animal Experimentation (Syrcle) tool for animal studies. A meta-analysis of quantitative data was performed to estimate the effect of PRF on bone repair in rats. Heterogeneity among the studies was assessed using the I2 statistic. The literature search retrieved 685 studies, 10 of which fulfilled the eligibility criteria, and 4 were included in the quantitative assessment. Analysis of the risk of bias revealed that most studies had a high risk of bias in performance and detection. Meta-analysis yielded divergent results and the absence of a statistically significant effect: PRF with control (standardized mean difference 2.54, 95% confidence interval -0.80-5.89; p = 0.14). In general, study heterogeneity was high (I2 ≥ 75.0%). The quality of the studies that influenced the conclusion of the review was based on the PICO, the sources and form of the search, the study selection criteria, the form of evaluation of publication bias, the evaluation of the quality of the studies, and data extraction by two researchers. PRF did not provide significant benefits for bone repair, resulting in unpredictable effects.

Survival of Dental Implants Placed Pre-Radiotherapy Versus Post-Radiotherapy in Native Bone: A Systematic Review.

PURPOSE: To systematically measure the survival rate of implants placed pre- and post-radiotherapy. MATERIALS AND METHODS: After performing a systematic literature exploration of 10 databases, observational and quasi-experimental studies and case series estimating the survival of dental implants in patients with head and neck cancer placed before, after, and without radiotherapy were included, with no limit on language or year of publication. The Joanna Briggs Institute Critical Appraisal was used to assess the risk of bias in eligible studies. RESULTS: During the first screening phase, 3,445 studies were found, among which 16 met the inclusion criteria. The median follow-up period was 60 months (range: 1 to 168 months). Seven (43.7%) articles had a moderate risk of bias, four (25%) had a high risk of bias, and five (31.3%) had a low risk of bias. The survival rate for post-radiotherapy, pre-radiotherapy, and without-radiotherapy implants was 80% to 100%, 89.4% to 97%, and 92.2% to 100%, respectively. CONCLUSION: Despite the alterations caused by ionizing radiation in peri-implant tissues, dental implants placed pre- and post-radiotherapy had high survival rates, similar to those placed without radiotherapy, which helps improve the condition of life of patients with head and neck cancer.

Dental trauma splints for the mixed dentition - A finite element analysis of splint material, splint extension, missing teeth, and PDL representation.

BACKGROUND/AIMS: Dental traumatic injuries are common in children during the mixed dentition stage. These injuries usually require splinting for stabilization, which is complicated by the various stages of the permanent tooth development and primary tooth exfoliation. The aim of this study was to evaluate the effect on mobility of splint materials and extensions for an avulsed central incisor, stabilized with and without the adjacent incisor under intrusive and extrusive loading with different periodontal ligament (PDL) conditions. MATERIALS AND METHODS: Seventeen 3D model variations were created from a CBCT scan of a 7-year-old patient without erupted permanent upper lateral incisors. A 1000 N palatal load on the right central incisor simulated the avulsion injury and created an increased alveolus and bone deformation, resulting in an increased PDL thickness of 0.45 mm. Wire-resin composite splints with 0.9 mm cross-section (WCS) or 1.0 mm diameter nylon-resin composite splints (NCS) were created. The models simulated conditions with and without the adjacent upper central incisor. Two PDL conditions were investigated, simulating detached PDL or PDL with polyether impression material-like properties. Mobility was calculated under simulated biting loads in horizontal and vertical (intrusive and extrusive) directions. RESULTS: The NCS allowed greater tooth mobility of the avulsed incisor than the WCS, irrespective of splint extension, PDL condition, or load application. During horizontal loading, polyether-like properties for the PDL allowed around 0.2 mm mobility of the avulsed tooth with the WCS, similar to the intact tooth, whereas a simulated detached PDL allowed 25% more mobility with a WCS than with a NCS. CONCLUSIONS: Based on the FEA analysis, a 1.0 mm NCS may be suitable for splinting avulsion injuries during the mixed dentition stage compared to the considerably more rigid WCS. The NCS models provided flexibility for PDL healing while maintaining stability, even when missing adjacent teeth increased span widths. Extensions beyond directly adjacent teeth did not alter the mobility with the NCS but should still be considered an extra protection in case of bond failure or exfoliation.

Implant Osseointegration in Grafted Autogenous Bone Blocks Fixed with Screws and Cyanoacrylate-Based Adhesive: Histomorphometric and Micro-CT Analyses.

PURPOSE: To evaluate implant osseointegration in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Also, grafted bone fixed either with an adhesive or screw was evaluated. MATERIALS AND METHODS: Two surgical defects in the parietal region of rabbits (n = 12) were performed in each animal. Autogenous bone blocks obtained were fixed anteriorly with a screw or cyanoacrylate-based adhesive. After 30 and 45 days of grafting procedures, implants were placed in bone blocks. Histomorphometric and microcomputed tomography (micro-CT) analyses of the implant area were performed at 30 days after implant surgery in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric analyses of bone-grafted areas were performed at 60 and 75 days in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric evaluations were carried out in implant and grafted bone areas. The micro-CT parameters evaluated were bone-to-implant contact, bone area fraction occupancy, bone volume fraction, trabecular thickness, trabecular separation, and trabecular number. RESULTS: No differences were observed in the micro-CT parameters for the screw and adhesive groups in all experimental periods. However, an increased quantity of immature bone volume was observed on the adhesive group in the grafted area after 75 days. The grafted area in the screw group (75 days) presented a decrease in the volume density of the immature bone compared with the screw group (60 days). There were no differences in both groups and experimental periods in soft tissue in the grafted area. CONCLUSION: No differences were observed in the osseointegration of implants placed in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Therefore, osseointegration in autogenous bone fixed with cyanoacrylate-based adhesive is viable.