Factors Influencing the Accuracy of Guided Surgery: An In Vitro Trial.

Purpose: To examine how the accuracy (linear and angular deviation) of implants placed using computer-guided surgery varies in relation to the type of surgical technique (fully guided, half-guided, vs freehand implant placement), bone density (type D1 to D4 bone), and type of support surface (tooth- vs mucosa-supported). Materials and Methods: A total of 32 mandible models were produced (16 partially edentulous and 16 edentulous) using acrylic resin, each calibrated to a different bone density (D1 to D4). Four implants planned using Mguide software were placed in each acrylic resin mandible. A total of 128 implants were placed, distributed according to bone density (D1 to D4, n = 32), the degree of intervention in the surgery (fully guided [FG] = 80, half-guided [HG] = 32, and freehand surgery [F] = 16), and the type of support surface (tooth-supported: n = 64 and mucosa-supported: n = 64). To determine the linear, vertical, and angular deviations between the planned three-dimensional position and the actual position of the implants, the linear and angular difference between them was calculated, with the analysis performed through preoperative and postoperative CBCT scans. The effect was analyzed using parametric tests and linear regression models. Results: All parameters of linear and angular discrepancy in the various regions analyzed (neck, body, and apex) were primarily influenced by the technique and, to a lesser extent, by the bone type, although both variables were predictive and highly significant. These discrepancies tend to increase in completely edentulous models. The regression models show that linear deviations increase by between 630.2 µm at neck level in the buccolingual direction and 836.7 µm at apex level in the mesiodistal direction when comparing the FG and HG techniques. This increase is accumulative when comparing the HG and F techniques. Regarding the effect of bone density, the regression models found that linear discrepancies increase by between 132.6 µm in the axial direction and 199.0 µm at the apex of the implant in the buccolingual direction with each reduction in bone density (D1 to D4). Conclusion: According to this in vitro study, the highest implant placement predictability is found among dentate models with high bone density and a fully guided surgical technique.

Patient-Centered Treatment Outcomes with Full-Arch PEEK Rehabilitation Supported on Four Immediate or Conventionally Loaded Implants. A Randomized Clinical Trial.

This study aims to assess the treatment outcomes (functional and subjective) of full-arch fixed hybrid rehabilitations made of PEEK (poly-ether-ether-ketone) with milled crowns of nano-filled composite (NFC) supported on four to six implants. In this randomized clinical trial, 34 edentate patients in the upper and/or the lower jaws were treated with the fixed hybrid dentures. In 16 patients (47.1% of the sample), the implants were loaded immediately (IL) by means of a provisional fixed rehabilitation made of PMMA (polymethylmethacrylate) screwed on Multi-Unit (MU) abutments connected after emplacement of the implant; however, in the counterparts (n = 18) these MU abutments were covered by healing caps and were left unloaded during two months (conventional loading protocol-CL), when all patients received a fixed hybrid PEEK-NFC rehabilitation on the upper and/or the lower jaw. Treatment outcomes were assessed 12 months after prostheses delivery. Functional outcomes were calculated according to masticatory performance, estimated by mixing ability tests of two colored chewing gums after ten chewing strokes, by the occlusal force/area recorded by pressure-sensitive sheets, and by electromyography of masseters and temporal muscles at maximum biteforce. The subjective outcomes of the treatment were assessed using both the oral satisfaction scale (visual analog scale) and the Spanish version of the Oral Health Impact Profile (OHIP-20). The findings of the present study showed that treatment with fixed PEEK-NFC hybrid prostheses significantly improved the masticatory performance, bite force, occlusal pattern, quality of life, and satisfaction, with the IL group being those with significantly higher occlusal bite forces and greater satisfaction in comparison with CL group. It should be concluded that PEEK-NFC hybrid prostheses can improve several patient-centered outcomes and that loading protocol significantly affects the patient's self-rated satisfaction.

[Microbiology of infections caused by dog and cat bites: A review]. / Microbiología de las infecciones causadas por mordeduras de perros y gatos en personas: Una revisión.

BACKGROUND: Bites caused by pets constitute 5% of the traumatic injuries registered in the emergency services. AIM: To know the main infectious agents present in dog and cat bites, both individually and jointly, in humans, as well as the predisposing factors that favor infection and its spread. METHODS: A bibliographic search was carried out in PubMed with the following search strategy: (("Bites, Human" [Mesh]) OR "Bites and Stings" [Mesh]) AND "Infection" [Mesh]. Twenty-four papers were included in the qualitative synthesis written in English or Spanish, clinical or descriptive cases and published between 2000 and 2019. RESULTS: Most frequently isolated species were Capnocytophaga canimorsus in dogs and Pasteurella multocida in cats. The existence of comorbidities in the individual, the bite on the hand, or the presence of signs of alteration of the general state of the bitten individual were considered as risk factors for the development of infection after the bite. CONCLUSIONS: All patients with animal bites should receive medical assistance, and the administration of an antibiotic prophylaxis regimen should be considered to reduce the risk of septic shock. Besides, it is important to advise the microbiology laboratory of the nature of the clinical samples obtained in order to reach the best etiological diagnosis.

Functional and Patient-Centered Treatment Outcomes with Mandibular Overdentures Retained by Two Immediate or Conventionally Loaded Implants: A Randomized Clinical Trial.

This study aims to assess the treatment outcomes (functional and subjective) of mandibular overdentures retained on two implants with or without an immediate loading protocol. In this randomized clinical trial, twenty fully edentulous patients were treated with a mandibular two-implant-retained overdenture and a complete new maxillary denture. In half of the sample, the implants were loaded immediately by means of VulkanLoc® abutments after emplacement of the implant, but in the counterparts, these VulkanLoc® abutments were connected to implants two months after the surgery (conventional protocol), and until that time the dentures were retained by healing abutments. Treatment outcomes were assessed at two, six, and twelve months after surgery. Functional outcomes were calculated according to masticatory performance, estimated by the mixed fraction of a two-coloured chewing gum after five, ten, and fifteen chewing strokes, by the occlusal force recorded by pressure-sensitive sheets, and by the bioelectrical muscular activity. The subjective outcomes of the treatment were assessed using both the oral satisfaction scale (visual analogue scale) and the Spanish version of the Oral Health Impact Profile (OHIP-20). The findings of the present study show that new complete dentures resulted in significant improvements in chewing ability, patient satisfaction, and oral health-related quality of life and that subsequent implant-retained overdentures produced further and faster significant improvements. The loading protocol may influence those positive self-reported outcomes rather than the objective functional evaluations.

Main 3D Manufacturing Techniques for Customized Bone Substitutes. A Systematic Review.

Clinicians should be aware of the main methods and materials to face the challenge of bone shortage by manufacturing customized grafts, in order to repair defects. This study aims to carry out a bibliographic review of the existing methods to manufacture customized bone scaffolds through 3D technology and to identify their current situation based on the published papers. A literature search was carried out using "3D scaffold", "bone regeneration", "robocasting" and "3D printing" as descriptors. This search strategy was performed on PubMed (MEDLINE), Scopus and Cochrane Library, but also by hand search in relevant journals and throughout the selected papers. All the papers focusing on techniques for manufacturing customized bone scaffolds were reviewed. The 62 articles identified described 14 techniques (4 subtraction + 10 addition techniques). Scaffold fabrication techniques can be also be classified according to the time at which they are developed, into Conventional techniques and Solid Freeform Fabrication techniques. The conventional techniques are unable to control the architecture of the pore and the pore interconnection. However, current Solid Freeform Fabrication techniques allow individualizing and generating complex geometries of porosity. To conclude, currently SLA (Stereolithography), Robocasting and FDM (Fused deposition modeling) are promising options in customized bone regeneration.

Microbiología de las infecciones causadas por mordeduras de perros y gatos en personas: una revisión / Microbiology of infections caused by dog and cat bites: a review

INTRODUCCIÓN: Las mordeduras causadas por animales de compañía constituyen el 5% de las heridas traumáticas registradas en los servicios de urgencias. OBJETIVO: Conocer los principales agentes infecciosos presentes en las mordeduras provocadas por perros y gatos, tanto de forma individual como conjunta; así como los factores que favorecen la infección. METODOLOGÍA: Se realizó una búsqueda bibliográfica en Pub-Med con la siguiente estrategia de búsqueda: (("Bites, Human"[Mesh]) OR "Bites and Stings"[Mesh]) AND "Infection"[Mesh]. Se incluyeron 24 trabajos en la síntesis cualitativa escritos en lengua inglesa o española, casos clínicos o descriptivos y publicados entre los años 2000 y 2019. RESULTADOS: Las especies más frecuentemente aisladas fueron Capnocytophaga canimorsus en perros y Pasteurella multocida en gatos. La existencia de comorbilidades en el individuo, la mordedura en la mano, o la presencia de signos de alteración del estado general del individuo mordido fueron considerados como factores de riesgo para el desarrollo de la infección tras la mordedura. CONCLUSIONES: Todos los afectados por mordeduras animales deben recibir asistencia médica y considerar la administración de una pauta de profilaxis antimicrobiana con el fin de reducir el riesgo de shock séptico. Por otro lado, es importante advertir al laboratorio de microbiología de la naturaleza de las muestras clínicas obtenidas para alcanzar el mejor diagnóstico etiológico.

BACKGROUND: Bites caused by pets constitute 5% of the traumatic injuries registered in the emergency services. AIM: To know the main infectious agents present in dog and cat bites, both individually and jointly, in humans, as well as the predisposing factors that favor infection and its spread. METHODS: A bibliographic search was carried out in PubMed with the following search strategy: (("Bites, Human" [Mesh]) OR "Bites and Stings" [Mesh]) AND "Infection" [Mesh]. Twenty-four papers were included in the qualitative synthesis written in English or Spanish, clinical or descriptive cases and published between 2000 and 2019. Results: Most frequently isolated species were Capnocytophaga canimorsus in dogs and Pasteurella multocida in cats. The existence of comorbidities in the individual, the bite on the hand, or the presence of signs of alteration of the general state of the bitten individual were considered as risk factors for the development of infection after the bite. CONCLUSIONS: All patients with animal bites should receive medical assistance, and the administration of an antibiotic prophylaxis regimen should be considered to reduce the risk of septic shock. Besides, it is important to advise the microbiology laboratory of the nature of the clinical samples obtained in order to reach the best etiological diagnosis.

Implant loss and crestal bone loss in early loading versus delayed and immediate loading in edentulous mandibles. A systematic review and meta-analysis.

BACKGROUND: Information about the risk of early loss and crestal bone loss of dental implants which have been loaded early is scant if compared with data available for those conventionally or immediately loaded. A meta-analysis of early loss and crestal bone loss in immediate or delayed loaded full mandibular denture retaining dental implants has been recently published. It is interesting to evaluate also the risks of early versus immediate and delayed loading in complete mandibular restorations. The purpose of this systematic review and meta-analysis was to study early (EL) versus immediate (IL) and delayed loading (DL) protocols in edentulous mandibles to determine whether differences exist in implant success and crestal bone loss. MATERIAL AND METHODS: The literature review was conducted in PubMed, Web of Science, and the Cochrane Library. Seven randomized clinical trials were included. RESULTS: The result of a meta-analysis of implant loss before 1 year in EL versus IL was 0.34 (95% CI: 0.08, 1.52), favoring the EL control group, while the outcome for crestal bone loss at the three-year observation was -0.10 (95% CI: -0.28, 0.09), with a tendency toward reduced bone loss for EL. In the EL versus DL group, the result of the meta-analysis of implant loss before one year was inconclusive, while in the comparison regarding crestal bone loss in the first year of observation, the result was -0.03 (95% CI: -0.08,-0.02) with a tendency to less bone loss in EL. CONCLUSIONS: The risk of early implant loss in the IL group was higher than in the EL group. The results in terms of early implant loss in EL versus DL are inconclusive. Besides, crestal bone loss is greater in immediately and delayed loaded implants, at 1 and 3 years of observation, compared to those loaded early. Key words:Dental implants, early dental implant loading, dental prostheses, implant- supported, alveolar bone loss, meta-analysis.

Effectiveness of Propolis in the Treatment of Periodontal Disease: Updated Systematic Review with Meta-Analysis.

In recent times, the use of natural products has gained momentum, either as a treatment or as adjuvants for other drugs in the treatment of different conditions. Propolis is a natural substance produced by bees which has proven useful for treating periodontal disease. This systematic review and meta-analysis gather evidence of the effectiveness of propolis in this kind of condition. The MEDLINE, CENTRAL, PubMed, EMBASE and Web of Science databases were searched for scientific articles to identify the findings published up to October 2020. The MeSH phrases used in the search were: "periodontal diseases AND propolis treatment"; "gingivitis AND propolis treatment"; "periodontitis AND propolis treatment"; "propolis treatment AND oral health"; "propolis AND oxidative stress AND periodontitis". The Boolean operator "AND" was used to combine the searches. Randomized trials where propolis was used in the treatment of different periodontal conditions were included. Non-randomized clinical studies were systematically reviewed and 224 studies were detected, eight of which met the criteria for inclusion in the meta-analysis. Only three of these were selected for quantitative synthesis. In conclusion, propolis is safe to use and can improve the results of periodontal disease treatment, reducing probing pocket depth compared with treatment with a placebo (difference in means, fixed effects -0.67 [95% CI: -0.84, -0.50]).

Implant loss and crestal bone loss in immediate versus delayed load in edentulous mandibles: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The current trend is to shorten the loading times of dental implants. However, information about the risk of early loss of implants that have been loaded immediately is scant if compared with data available for those conventionally loaded. PURPOSE: The purpose of this systematic review and meta-analysis was to study immediate (IL) and delayed loading (DL) protocols in edentulous mandibles to determine whether differences exist in implant success and crestal bone loss and to evaluate these possible differences in relation to the type of prosthesis and the splinting of the implants. MATERIAL AND METHODS: The literature review was conducted in PubMed, Scopus, and the Cochrane Library. Nine randomized clinical trials were included. RESULTS: The result of a meta-analysis of implant loss before 1 year was 2.63 (95% CI: 1.22, 5.68), favoring the DL control group, while the outcome for crestal bone loss at the observation year was 0.42 (95% CI: -0.35, 1.20), with a tendency toward reduced bone loss for DL. CONCLUSIONS: The risk of early loss in the IL group was higher than that in the DL group. For removable prostheses and nonsplinted implants, DL was preferred. The quality of scientific evidence significantly favors DL.

Classification of sinonasal pathology associated with dental pathology or dental treatment.

BACKGROUND: The pathologies of the posterior teeth in the first and second quadrant and their treatments can be associated with pathology of the maxillary sinus in up to 30% of the cases. Sinus lift surgery in order to place dental implants have increased their incidence. It is necessary, therefore, to address sinonasal pathology (SN) related to dental pathology (DP) or dental treatments (DT) from an interdisciplinary point of view by establishing collaborative working groups between Dentistry (DEN) and Otolaryngology (ENT), as well as by developing registries and establishing coordinated diagnosis and treatment protocols of sinonasal pathology. The aim of this study was to present a brand new and useful classification that relates dental pathology and dental treatments performed on antral teeth with sinonasal pathology to facilitate communication between dentists and otolaryngologists. METHODS: A review of the literature was performed and a classification which related dental pathology and treatments to sinonasal pathology was developed. RESULTS: Six categories are described in our system: absence of sinonasal or dental pathology (0); patients with dental pathology associated (1) or not (4) with sinonasal pathology; 2 and 5- patients with dental treatment not associated (2) or associated (5) with sinonasal pathology; and patients with sinonasal pathology without dental pathology (3). The classification has applications in diagnosis (association and possible causal relationship between the sinonasal and dental pathology) and in the treatment of these pathologies simultaneously or sequentially. CONCLUSIONS: This classification integrates the presence or absence of dental pathology or dental treatment, and its association or not it with sinonasal pathology. Moreover, it facilitates the communication between dentists and otolaringologists and eases the registration of information and the planning of dental, implant and sinus lift treatments.

Effect of Rough Surface Platforms on the Mucosal Attachment and the Marginal Bone Loss of Implants: A Dog Study.

: The preservation of peri-implant tissues is an important factor for implant success. This study aimed to assess the influence of the surface features of a butt-joint platform on soft-tissue attachment and bone resorption after immediate or delayed implant placement. All premolars and first molars of eight Beagle dogs were extracted on one mandible side. Twelve-weeks later, the same surgery was developed on the other side. Five implants with different platform surface configurations were randomly inserted into the post-extracted-sockets. On the healed side, the same five different implants were randomly placed. Implants were inserted 1 mm subcrestal to the buccal bony plate and were connected to abutments. The primary outcome variables were the supracrestal soft tissue (SST) adaptation and the bone resorption related to the implant shoulder. The SST height was significantly larger in immediate implants (IC95% 3.9-4.9 mm) compared to delayed implants (IC95% 3.1-3.5 mm). Marginal bone loss tended to be higher in immediate implants (IC95% 0.4-0.9 mm) than in delayed implants (IC95% 0.3-0.8 mm). Linear-regression analysis suggested that the SST height was significantly affected by the configuration of the platform (0.3-1.9 mm). Roughened surface platforms resulted in higher SST height when compared to machined surface platforms. Marginal bone loss was less pronounced in roughened designs.

Sinus lift through the use of a surgical guide: a case report.

AIM: Sinus lift is a common procedure to achieve bone height in the maxillary posterior region. This surgery can be performed through either a lateral or crestal approach. Preoperative planning usually entails CBCT and intraoperative evaluation at the time of surgery. This article presents a case in which a surgical guide was made by digitally planning for the performance of a sinus lift procedure through a lateral approach. CASE PRESENTATION: A 59-year-old partially edentulous female patient underwent sinus lift surgery using a stereolithographic guide designed in NemoStudio software and printed using clear, biocompatible MED610. On the day of surgery, the bone guide was fixed with pins, and the lateral window was made by piezoelectric surgery. There were no intraoperative or postoperative incidents. DISCUSSION: There are very few descriptions in the literature of the use of surgical guides for sinus lift. In this case, the advantages of its use were the precision in the performance of the window, the speed and comfort of access, and the retractor effect of the guide on the flap. The main drawback was the need to raise a wide flap to achieve good settlement of the guide. CONCLUSION: The present case, which presents an innovative technique for the opening of the lateral window in a sinus lift procedure, is interesting for the advancement of computer-guided surgery.

Laryngeal paralysis detected in preoperative laryngoscopy in malignant and benign thyroid disease. Systematic review and meta-analysis. / Parálisis laríngea detectada en la laringoscopia preoperatoria en enfermedad de tiroides maligna y benigna. Revisión sistemática y metaanálisis.

There is controversy regarding the performance of preoperative laryngoscopy (LP) in thyroid surgery, with different recommendations being made, based on observational studies, in various publications. The aim of the study was to know the prevalence of laryngeal paralysis found in the LPs of patients who underwent thyroidectomy in benign and malignant pathology. A systematic review was carried out with 29 articles included for the qualitative study and a meta-analysis of 13 articles in which the data could be obtained to evaluate the same effect (in all patients in which an LP was carried out, those with preoperative laryngeal paralysis were included, and assigned to malignant or benign postoperative histology groups). The pooled prevalence of preoperative paralysis in benign pathology was 1.1% (95% CI 0.7 to 1.7%, 71% I2) and in 6.3% malignant pathology (95% CI 3.8 to 9.4%; I2 85%). The prevalence was significantly higher among patients with malignant pathology with an estimated effect RR 5.66, 95% CI, 2.48, 12.88. The studies analyzed present biases that will need to be corrected in future research, eliminating blinding biases in the selection and allocation of patients or in the laryngoscopy technique used. The LP in thyroid surgery evaluates possible disorders of laryngeal motility. The prevalence of laryngeal paralysis in thyroid pathology found in LPs in patients with a postoperative diagnosis of malignant pathology was higher than in the benign pathology group. This information is necessary for interpreting the intraoperative neuromonitoring signal and for making informed decisions.

Preload loss of abutment screws after dynamic fatigue in single implant-supported restorations. A systematic review.

BACKGROUND: To carry out a systematic literature review of the causes of preload loss of the abutment screws, of internal and external connection implants, tightened to different torque values and subjected to cyclic loading. MATERIAL AND METHODS: A systematic search was conducted in PubMed, EMBASE, and Cochrane Library databases with reference to in vitro studies in which internal and external connection implants were subjected to cyclic loads to determine the degree of loosening of the abutment screws after loading. RESULTS: The reviewed studies tested distinct implant connections (mostly externally hexed, and morse taper) subjected to diverse cycles (from 16667 to 1 million), with loads ranging from 0-400 Nw, using screws of different materials and designs that were tightened into torques between 20-45 Ncm, Accordingly after loading the percentage of torque loss ranges between 16.1% to 39%. CONCLUSIONS: Most of the studies indicate that the internal connection, together with the morse taper, best resists cyclic loading in terms of screw loosening in single-tooth implants. Key words:Dental Implants, Dental Implant-Abutment Design, Torque, In Vitro Techniques, Systematic Review.