The effect on the performance of a dynamic navigation system of superimposing a standard tessellation language (STL) file obtained with an intraoral scan on a cone beam computer tomograph (CBCT). An experimental in vitro study.

OBJECTIVES: To compare the accuracy and operative time of implant placement using a dynamic computer assisted implant surgery (dCAIS) system based on a cone beam computer tomography (CBCT) image, with and without superimposing a standard tessellation language (STL) file of an intraoral scan of the patient. METHODS: Ten identical resin models simulating an upper maxilla with posterior edentulism were assigned to two groups. In the CBCT+STL group, a CBCT file and an intraoral STL file were superimposed and used for registration; in the CBCT group, registration was performed using CBCT images. Six implants were placed in each model using the Navident® dynamic navigation system. Anatomy registration was performed by tracing points on the CBCT or STL image, depending on the group. Preoperative and postoperative CBCT images were overlaid to assess implant placement accuracy. RESULTS: Sixty implants were analyzed (30 implants in each group). 3D platform deviation was significantly lower (mean difference (MD): 0.17 mm; 95% confidence interval (CI): 0.01 to 0.23; P = 0.039) in the CBCT+STL group (mean: 0.71mm; standard deviation (SD): 0.29) than in the CBCT group (mean: 0.88mm; SD: 0.39). The remaining accuracy outcome variables (angular deviation MD: -0.01; platform lateral deviation MD: 0.08mm; apex global MD: 0.01mm; apex depth MD: 0.33mm) and surgery time (MD: 3.383 min.) were similar in both groups (p>0.05). CONCLUSIONS: The introduction of an intraoral scan (STL) seems to reduce deviations slightly in dental implant placement with dCAIS systems. However, the clinical repercussion of this improvement is questionable. CLINICAL SIGNIFICANCE: Superimposing an intraoral scan on the CBCT image does not seem to increase the accuracy of dCAIS systems but can be useful when radiographic artifacts are present.

The influence of radiographic marker registration versus a markerless trace registration method on the implant placement accuracy achieved by dynamic computer-assisted implant surgery. An in-vitro study.

OBJECTIVES: This study aimed to compare the effect the radiographic marker registration (RMR) and markerless tracing registration (MTR) on implant placement accuracy using a dynamic computer-assisted implant surgery system (dCAIS). Additionally, this study aimed to assess the surgical time and whether the implant location influences the accuracy of the two registration methods. METHODS: 136 dental implants were randomly allocated to the RMR or MTR group and were placed with a dCAIS in resin models. Preoperative and postoperative Cone Beam Computer Tomograms (CBCT) were overlaid and implant placement accuracy was assessed. Descriptive and multivariate analysis of the data was performed. RESULTS: Significant differences (P < 0.001) were found for all accuracy variables except angular deviation (RMR:4.30° (SD:4.37°); MTR:3.89° (SD:3.32°)). The RMR had a mean 3D platform deviation of 1.53 mm (SD:0.98 mm) and mean apex 3D deviation of 1.63 mm (SD:1.05 mm) while the MTR had lower values (0.83 mm (SD:0.67 mm) and 1.07 mm (SD:0.86 mm), respectively). In the MTR group, implant placement in the anterior mandible was more accurate (p < 0.05). Additionally, MTR did not significantly increase the surgical time compared with RMR (P = 0.489). CONCLUSIONS: MTR seems to increase the accuracy of implant placement using dCAIS in comparison with the RMR method, without increasing the surgical time. The operated area seems to be relevant and might influence the implant deviations. CLINICAL SIGNIFICANCE: Considering the limitations of this in-vitro study, MTR seems to provide a higher accuracy in implant placement using dCAIS without increasing the surgical time. Furthermore, this method does not require radiographic markers and allows re-registration during surgery.

Peri-implantitis in patients without regular supportive therapy: Prevalence and risk indicators.

OBJECTIVES: To determine the prevalence of peri-implant diseases in patients treated in a university setting without a regular peri-implant supportive therapy schedule, and to identify the risk indicators associated with peri-implantitis. MATERIAL AND METHODS: A retrospective cohort study was made of patients with dental implants with at least 12 months of functional loading who did not receive regular peri-implant supportive therapy. Patient- and implant-related variables were retrieved, and clinical and radiological examinations were performed. Descriptive and bivariate analyses and multilevel logistic regression analyses were performed to identify factors associated with peri-implantitis. RESULTS: A total of 213 implants in 88 patients were analyzed. The patient-level prevalence of peri-implantitis and peri-implant mucositis was 26.1% (95%CI: 16.7%-35.5%) and 44.3% (95%CI: 34.0%-54.6%), respectively. Peri-implant diseases were significantly more frequent when the width of the keratinized mucosa was < 2 mm (OR = 5.26; 95%CI: 1.24-22.26; p = 0.024), and when there was 12 month post-loading bone loss (OR = 2.96; 95%CI: 1.35-6.52; p = 0.007). CONCLUSIONS: Peri-implantitis is a common finding in patients without regular peri-implant supportive therapy (prevalence 16.7-35.5%). A thin peri-implant keratinized mucosa (< 2 mm) and a higher degree of bone remodeling after loading seem to be the main risk factors for peri-implantitis in this patient profile. CLINICAL RELEVANCE: Patients who do not engage in supportive peri-implant maintenance have a higher risk of peri-implantitis. A thin keratinized mucosa and bone loss during the first year of loading are predisposing factors for peri-implantitis.

Early complications and quality of life in patients with immediately loaded implant-supported maxillary partial rehabilitations: A prospective cohort study / Complicaciones tempranas y calidad de vida en pacientes con rehabilitaciones parciales maxilares implantosoportadas con carga inmediata: un estudio de cohorte prospectivo

Background: Immediate loading of dental implants is considered an excellent option to reestablish function and aesthetics in a short period of time, thereby reducing the psychological impact of edentulism. The aim of this study was to describe the incidence of complications in immediately loaded implant-supported single or partial maxillary provisional rehabilitations; to assess changes in patient quality of life (QoL); to evaluate patient overall satisfaction; and to determine whether the occurrence of complications affects these outcomes. Material and Methods: Patients requiring partial rehabilitation with implants in the maxilla were included in a prospective cohort study. In all cases, implant-based restoration with an immediate loading protocol was indicated. A provisional restoration was placed within 72 hours after implant placement. Patient QoL was measured at the first appointment and just before placing the final restoration, using two validated questionnaires. All mechanical and biological complications occurring up until placement of the final restoration were documented. A descriptive and bivariate analysis of the data was performed. Results: Thirty-five patients with 40 prostheses supported by 60 implants were analyzed. Three implant failures were observed, yielding a 95% survival rate. Five provisional prosthesis fractures and two prosthetic screw loosenings were recorded in four patients. A significant reduction in OHIP-14 score was observed. Likewise, significant differences were found in the results of the QoLFAST-10, with a mean difference in score of 7.3 between the initial and final evaluation. Conclusions: Patients receiving immediately loaded implant-supported single or partial maxillary provisional rehabilitations seem to have a low risk of developing early mechanical (13.3%) or biological complications (5%)...(AU)

Clinical practice guideline of the spanish society of oral surgery for oral surgery in patients with coagulation disorders / Guía de práctica clínica de la sociedad española de cirugía bucal para cirugía oral en pacientes con trastornos de la coagulación

Background: The number of patients treated with coagulation disorders, and more specifically with anticoagulanttherapy, has increased worldwide in recent years due to increased life expectancy in developed countries. Theprotocols for managing this type of patient in oral surgery has varied over recent years, especially after the appear-ance of new direct-acting oral anticoagulants (DOACs). The assessment of risk of bleeding in this type of patientwhen undergoing a surgical procedure continues to be a controversial issue for patients, dentists and general prac-titioners. The objective of this document is to offer recommendations, based on evidence, for decision making forpatients with coagulopathies who require dental surgical intervention. Material and Methods: Based on the indications of the “Preparation of Clinical Practice guidelines in the NationalHealth System. Methodological manual”, we gathered a group of experts who agreed on 15 PICO questions basedon managing patients with coagulation disorders in dental surgical procedures, such as fitting of implants or dentalextractions.Results: The 15 PICO questions were answered based on the available evidence, being limited in most cases due tothe lack of a control group. Two of the PICO questions were answered by the experts with a grade C recommendation,while the rest were answered with grade D.Conclusions: The results of this review highlight the need to undertake well designed clinical trials with controlgroups and with a representative sample size.(AU)

Validity and reliability of the Spanish version of the consultation and relational empathy measure in dental students (Sp-Dent-CARE): A cross-sectional study.

INTRODUCTION: An evaluation was made of the psychometric properties of a Spanish version of the Consultation and Relational Empathy Measure (CARE) to assess relational empathy in undergraduate dental students. In addition, the influence of demographic, socio-economic and consultation-related factors upon the degree of perceived empathy and overall satisfaction was studied. MATERIALS AND METHODS: A cross-sectional study was carried out in patients seen in the Oral Surgery Unit by fourth year dental students. Dentists, specialized translators and psychologists developed the translation of the questionnaire. After a pilot test, a convenience sample of patients was included. Construct validity was tested by factor analysis using principal component analysis with varimax rotation and Kaiser standardization, and internal consistency was assessed by Cronbach's α. RESULTS: Two pilot tests were carried out with a panel of experts until the final version of the questionnaire was established. In the validation stage, 191 patients participated (92 men and 99 women), with a mean age of 52.5 ± 17 years. The mean score of the CARE measure was 47.2 ± 4.4, and 57.6% of the patients (n = 110) reported the maximum score on the questionnaire. The final version showed a 1-factor solution explaining 68.6% of the total variance, with excellent final internal consistency (α = 93.4%). CONCLUSION: The Spanish version of the CARE measure affords high reliability and validity in assessing relational empathy in dental students. Perceived empathy is related to overall satisfaction. Patient demographics and the number of visits do not influence perceived empathy.

Factors Affecting Implant Surface Roughness and Platform Alterations After Implantoplasty: An In Vitro Study Simulating Different Clinical Scenarios.

Purpose: To determine which clinical factors might affect the postimplantoplasty presence of residual threads, platform alterations, and level of surface roughness. Materials and Methods: A total of 60 implants were placed in 20 resin models (10 edentulous maxillary models and 10 partially dentate mandibular models), and 5-mm peri-implant bone defects were created. These models were then placed in simulation mannequins. A single researcher performed the implantoplasties, which were divided into the following groups: favorable situation (FS; maxillary incisors without adjacent teeth), unfavorable situation (US; mandibular molars with adjacent teeth), crown (C; mandibular premolars with a prosthetic crown and adjacent teeth), and noncrown (NC; mandibular premolars with adjacent teeth and without a prosthetic crown). The presence of residual threads, gaps in the implant-abutment interface, and silicone debris was assessed using a scanning electron microscope (SEM), and the surface roughness (Sa and Sz) was analyzed with a confocal optical microscope. A descriptive and bivariate analysis was conducted. Results: The postimplantoplasty surfaces were significantly smoother than the original implant surfaces. The surface roughness was significantly higher in the US group than in the FS group. Gaps in the implant-abutment interface were infrequent (6.67%; 95% CI = 2.62 to 15.93) and only appeared in the posterior zone. The odds ratio for the presence of residual threads and silicone debris (US group vs FS group) was 7.1 (95% CI = 4.15 to 12.14; P < .001) and 5.53 (95% CI = 3.21 to 9.53; P < .001), respectively. When a prosthetic crown was present, residual threads were 7 times more likely to be found (OR = 7.0; 95% CI = 3.5 to 13.99; P < .001). Conclusions: Implantoplasty leads to a significant reduction in the surface roughness of implants but is affected by several variables. Performing implantoplasty on posterior mandibular implants with adjacent teeth seems to be more challenging compared to implants placed in the anterior region of a fully edentulous maxilla. The presence of a prosthetic crown should also be considered as a relevant factor. Furthermore, implantoplasty can sometimes cause gaps in the implant-abutment interface and an accumulation of silicone debris, especially in areas with limited access.

In Vitro Characterization of an Anodized Surface of a Dental Implant Collar and Dental Abutment on Peri-Implant Cellular Response.

The purpose of this paper was to determine the effect of anodization on the in vitro proliferation and adhesion of immortalized human keratinocytes (HaCats) and mouse bone marrow-derived mesenchymal stem cells (BM-MSCs) in Titanium Grade 23 (Ti6Al4V ELI) discs and to describe the surface topography, roughness, and composition of dental implants (body and collar) and abutments submitted to an area-specific anodization process. HaCat cells and BM-MSCs were seeded onto discs with three different surface treatments: machined, area-specific anodization for abutments, and area-specific anodization for implant collars. Cell proliferation was assessed using a resazurin-based fluorescent dye on days 1, 3, and 7, while cell adhesion was examined using scanning electron microscopy (SEM). Surface topography, roughness, and composition were evaluated for six implant bodies with an anodized rough surface, six anodized implant smooth collars, and six anodized prosthetic abutments. Both HaCats and BM-MSCs showed increased viability over time (p < 0.001) with no statistically significant differences among the different surfaces (p = 0.447 HaCats and p = 0.631 BM-MSCs). SEM analysis revealed an enhanced presence and adhesion of HaCat cells on the anodized surface for the implant collars and an increased adhesion of BM-MSCs on both the anodized and machined surface abutments. The topography characteristics of the treated implants and abutments varied depending on the specific implant region. Chemical analysis confirmed the presence of oxygen, calcium, phosphorus, and sodium on the anodized surfaces. The area-specific anodization process can be utilized to create variable topography, increase the specific surface area, and introduce oxygen, calcium, phosphorus, and sodium to dental implants and abutments. While BM-MSCs and HaCat cells showed similar adhesion and proliferation on anodized and machined surfaces, a positive interaction between anodized Ti6Al4V ELI surfaces and these two cell lines present in the peri-implant mucosa was observed. Due to the limitations of the present study, further research is necessary to confirm these findings.

Role-playing para la mejora de las habilidades comunicativas en estudiantes de grado de Odontología. Un ensayo clínico no aleatorizado / Role-playing for the improvement of communication skills in Dentistry undergraduate students. A non-randomized clinical trial

Introducción: Se trata de analizar el impacto de una secuencia formativa en la autopercepción del alumnado sobre las habilidades comunicativas. Secundariamente, se pretende conocer el grado de satisfacción del alumnado en relación con las actividades propuestas. Mètodos: Es un estudio cuasi experimental realizado sobre cuatro de los subgrupos de prácticas de la asignatura obligatoria de cuarto curso Cirugía Bucal Clínica e Implantología. Dos de los subgrupos recibieron una secuencia formativa específica para la mejora de sus habilidades comunicativas (n = 40) y los otros dos actuaron como controles (n = 47). Al inicio y al final del estudio, los participantes respondieron el cuestionario validado SE-12 de autopercepción sobre comunicación odontólogo-paciente. La estrategia evaluativa fue continua y formativa. Se analizaron y compararon las puntuaciones de los distintos indicadores e instrumentos de evaluación empleados.Resultados: A excepción de un alumno del grupo de control, todos los estudiantes participaron de forma activa en el proyecto. En ambos grupos se observó una mejora estadísticamente significativa en la percepción de las habilidades comunicativas (p < 0,001). No obstante, los alumnos asignados al grupo experimental percibieron una mejora significativamente mayor (diferencia de medias = 0,96 puntos; intervalo de confianza al 95% = 0,66-1,27; p < 0,001). Los alumnos valoraron la secuencia con un 8,56 (desviación estándar = 1,14).Conclusiones: La implementación de la secuencia formativa produjo una mejora en la percepción que tienen los estudiantes sobre sus habilidades comunicativas. Es necesaria la inclusión de programas longitudinales de formación en comunicación en los planes de estudio para acreditar la consecución de las competencias comunicativas.(AU)

Introduction: To analyze the impact of a training-learning sequence on students' self-perception of communication skills. Secondarily, to know the degree of student satisfaction in relation to the proposed activities.Methods: A quasi-experimental study was carried out on four of the clinical practice subgroups of Clinical Oral Surgery and Implantology (fourth year of study). Two of the subgroups received a specific training-learning sequence to improve their communication skills (n = 40) and the other two served as controls (n = 47). At the beginning and end of the study, the participants answered the validated SE-12 self-perception questionnaire on dentist-patient communication. The evaluation strategy was continuous and formative. The scores of the different indicators and evaluation instruments used were analyzed and compared.Results: Except for one student in the control group, all students participated actively in the project. In both groups, a statistically significant improvement was observed in the perception of communication skills (p < 0.001). However, the students assigned to the experimental group perceived a significantly greater improvement (difference in means = 0.96 points; 95% confidence interval = 0.66-1.27; p < 0.001). The students valued the training-learning sequence with an 8.56 (standard deviation = 1.14).Conclusions: The implementation of the training-learning sequence produced an improvement in the perception that students have about their communication skills. It is necessary to include longitudinal training programs in communication in the curricula to prove the achievement of communication skills competences.(AU)

Effect of Implantoplasty on Roughness, Fatigue and Corrosion Behavior of Narrow Diameter Dental Implants.

Implantoplasty (IP) is used in dental implants with peri-implantitis and aims to remove threads and polish rough surfaces in order to prevent bacterial colonization. As a result of this procedure, implant strength might be compromised. We tested 20 tapered screw-shaped Ti6Al4V dental implants with a simulated bone loss of 50%. Ten implants underwent IP and 10 served as controls. Surface topography (Sa, Sz, Ssk, and Sdr) was analyzed with a confocal optical microscope. Subsequently, a minimum of four series of cyclic loads were applied with a servo-hydraulic mechanical testing machine (5 × 106 cycles at 15 Hz, between a maximal nominal value-starting at 529 N in the IP group and 735 N in the control group-and 10% of that force). We recorded the number of cycles until failure and the type of failure. Implant failure was analyzed by visual inspection and scanning electron microscopy. Open circuit potential and potenctiodynamic tests were carried out with high precision potentiostat using Hank's solution at 37 °C to evaluate the effect of the implantoplasty on the corrosion resistance. Implantoplasty significantly reduced the surface topography values (median) and interquartile range (IQR); Sa from 1.76 (IQR = 0.11) to 0.49 (IQR = 0.16), Sz from 20.98 (IQR = 8.14) to 8.19 (IQR = 4.16), Ssk from 0.01 (IQR = 0.34) to -0.74 (IQR = 0.53) and Sdr from 18.20 (IQR = 2.26) to 2.67 (IQR = 0.87). The fatigue limits of the control and implantoplasty groups were 551 N and 529 N, respectively. The scanning electron micrographs showed fatigue striations indicating fatigue failure. Besides, the fractographic analysis revealed a typical brittle intergranular fracture mechanism. The infinite life range of the dental implants evaluated was largely above the threshold of usual chewing forces. Implantoplasty seems to render a fairly smooth surface and has a limited impact on fatigue resistance. In addition, implantoplasty produces a decrease in the corrosion resistance of the implant. Corrosion current density from 0.019 µA/cm2 for as-received to 0.069 µA/cm2 in the interface smooth-roughened dental implant. These places between the machining and the rough area of the implant are the most susceptible, with the appearance of pitting.

Accuracy of dental implant placement with or without the use of a dynamic navigation assisted system: A randomized clinical trial.

OBJECTIVES: To assess dental implant placement accuracy with a dynamic computer-assisted implant surgery (dCAIS) system and a freehand approach. Secondarily, to compare the patients' perception and quality of life (QoL) with the two approaches. METHODS: A double-arm randomized clinical trial was conducted. Consecutive partially edentulous patients were randomly allocated to the dCAIS or standard freehand approach groups. Implant placement accuracy was evaluated by overlapping the preoperative and postoperative Cone Beam Computer Tomographs (CBCT) and recording linear deviations at the implant apex and platform (in mm) and angular deviations (in degrees). Questionnaires recorded self-reported satisfaction, pain and QoL during surgery and postoperatively. RESULTS: Thirty patients (22 implants) were enrolled in each group. One patient was lost to follow-up. A significant difference (p < .001) in mean angular deviation was found between the dCAIS (4.02°; 95% CI: 2.85 to 5.19) and the FH (7.97°; 95% CI: 5.36 to 10.58) groups. Linear deviations were significantly lower in the dCAIS group, except for the apex vertical deviation, where no differences were found. Although dCAIS took 14 min longer (95% CI: 6.43 to 21.24; p < .001), patients in both groups considered the surgical time acceptable. Postoperative pain and analgesic consumption during the first postoperative week were similar between groups and self-reported satisfaction was very high. CONCLUSION: dCAIS systems significantly increase the accuracy of implant placement in partially edentulous patients in comparison with the conventional freehand approach. However, they increase the surgical time significantly and do not seem to improve patient satisfaction or reduce postoperative pain.

Patient-centered outcomes after surgical treatment of peri-implantitis: a prospective clinical study

Background: Peri-implantitis is an inflammatory process affecting soft and hard tissues surrounding dental implants, causing progressive marginal bone loss. Peri-implant surgery is the treatment of choice. However, evidence about its impact on patients' quality of life (QoL) is limited. This study aimed to assess pain and QoL in the first seven post-operative days and measure patient satisfaction at the end of this period.Material and methods: A prospective cohort study was conducted in patients with peri-implantitis. Patients reported pain on a visual analogue scale (VAS) ranging from 0 to 100mm every day during the first week after surgery. They then completed the OHIP-14sp questionnaire. A descriptive and inferential data analysis was used to assess the effect of surgical approach (resective, regenerative or combined), gender and working status on pain, satisfaction and QoL.Results: Forty-one patients (93,2%) completed the daily pain VAS; scores ranged from 0 to 95 mm. Gender, occupation, or type of surgery had no significant effect upon its evolution. The mean total OHIP-14sp score was 16.7 (range = 5 to 33), indicating low to moderate deterioration in perceived oral health. Postoperative OHRQoL was significantly higher in working patients (mean difference (MD): 3.94; P = 0.042), and with the regenerative (MD: 6.34; P = 0.044) or the combined approach (MD: 5.41; P = 0.027).Conclusions: Considering the limitations of this study, postoperative pain was mild to moderate and decreased after the third day. Surgical treatment of peri-implantitis has an impact on QoL, especially when augmentation procedures are involved. This impact is higher in working patients. (AU)

Comparison of external, internal flat-to-flat, and conical implant abutment connections for implant-supported prostheses: A systematic review and network meta-analysis of randomized clinical trials.

STATEMENT OF PROBLEM: The implant abutment connection interface has been considered one of the major factors affecting the outcome of implant therapy. However, drawbacks of traditional meta-analyses are the inability to compare more than 2 treatments at a time, which complicates the decision-making process for dental clinicians, and the lack of a network meta-analysis. PURPOSE: The purpose of this network meta-analysis was to assess whether the implant abutment connection influences the outcome of implant-supported prostheses. MATERIAL AND METHODS: An electronic search was undertaken to identify all randomized clinical trials comparing the effect of at least 2 different implant abutment connection designs published from 2009 up to May 2020. Outcome variables were implant survival rate, peri-implant marginal bone loss, and biologic and prosthetic complication rates at 12 months after prosthetic loading. Relevant information was extracted, and quality and risk of bias assessed. Pairwise meta-analyses and network meta-analyses based on a multivariate random-effects meta-regression were performed to assess the comparisons (α=.05 for all analyses). RESULTS: For peri-implant marginal bone loss and prosthetic complications, conical interfaces were determined to be the most effective, with significant differences when compared with external hexagonal connections (P=.011 and P=.038, respectively). No significant differences were found among the implant abutment connections in terms of survival and biologic complications (P>.05 in all direct, indirect, and mixed comparisons). CONCLUSIONS: After 1 year of loading, conical connections showed lower marginal bone loss and fewer prosthetic complications than external hexagonal connections. However, the implant abutment connection design had no influence on the implant survival and biologic complication rates.

Ion release and local effects of titanium metal particles from dental implants: An experimental study in rats.

BACKGROUND: The objective of this study was to evaluate the accumulation of ions in blood and organs caused by titanium (Ti) metal particles in a mandibular defect in rats, together with a description of the local reaction of oral tissues to this Ti alloy debris. METHODS: Twenty Sprague-Dawley rats were randomly distributed into three groups: an experimental group with a mandibular bone defect filled with metallic debris obtained by implantoplasty; a positive control group; and a negative control group. Thirty days after surgery, the rats were euthanized and perilesional tissue surrounding the mandibular defect was removed, together with the lungs, spleen, liver, and brain. Two blood samples were collected: immediately before surgery and before euthanasia. The perilesional tissue was histologically analyzed using hematoxylin-eosin staining, and Ti, aluminum, and vanadium ion concentrations in blood and organs were measured by TQ-ICP-MS. Descriptive and bivariate analyses of the data were performed. RESULTS: All rats with implanted metal debris showed metal particles and a bone fracture callus on the osseous defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells (MNGCs). The experimental group had a significant higher concentration of Ti ions in all studied organs except lung tissue (p < 0.05). In addition, there were more V ions in the brain in the experimental group (p = 0.008). CONCLUSIONS: Although further studies are required to confirm the clinical relevance of these results, Ti metal particles in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction.

Comparison of two different lingual flap advancement techniques and vascular structure identification: a human cadaver study

Background: One of the most frequent complications in guided bone regeneration (GBR) is wound dehiscence, which compromises treatment outcomes. Thus, primary tension-free suture is essential to avoid wound dehiscence. The purpose of this study was to compare the extension of 2 different mandibular flaps in human cadaveric specimens, and to measure the size of the supraperiosteal blood vessels. Material and methods: Five freshly unfrozen human cadaveric specimens were used. Arteries and veins were marked and bilateral classical lingual flaps (extending from the second premolar to the retromolar area) were prepared. In one side, the mylohyoid muscle was detached to increase the coronal extension of the flap. An implant drill was used to measure the extension of the flap after exerting 30 g of traction, before and after detaching the mylohyoid muscle. The size of the largest vascular structures of the flap was measured using a periodontal probe. Results: The classical flap extension was 5.99 mm (95% confidence interval (CI): 5.08 to 6.90), while the coronally advanced flap extension with mylohyoid muscle detachment was 14.96 mm (95%CI: 10.81 - 19.11). A statistically significant difference was found between the 2 groups (p= 0.0002), with a mean extension difference was 8.97 mm (95%CI: 5.02 to 12.91). The mean largest artery had 0.20 mm of diameter (95%CI: 0.15 - 0.26). Conclusions: The detachment of the mylohyoid muscle from the lingual flap allows to significantly increase its extension by 2.5 times. The superficial arteries found in the lingual flap have a small diameter (around 0.2mm). (AU)

Evaluation of the inflammatory and osteogenic response induced by titanium particles released during implantoplasty of dental implants.

Implantoplasty is a mechanical decontamination technique that consists of removing the threads and polishing and smoothing the dental implant surface. During implantoplasty there is a large release of titanium metal particles that might provoke a proinflammatory response and reduce the viability of osteogenic cells. We analyze the inflammatory and osteogenic response induced by Ti6Al4V particles released during implantoplasty and by as-received commercially pure Ti particles. Macrophages stimulated with metal particles obtained by implantoplasty and with as-received Ti particles showed an increased proinflammatory expression of TNF-α and a decreased expression of TGF-ß and CD206. Regarding cytokine release, there was an increase in IL-1ß, while IL-10 decreased. The osteogenic response of Ti6Al4V extracts showed a significant decrease in Runx2 and OC expression compared to the controls and commercially pure Ti extracts. There were no relevant changes in ALP activity. Thus, implantoplasty releases metal particles that seems to induce a pro-inflammatory response and reduce the expression of osteogenic markers.

Is serum C-terminal telopeptide cross-link of type 1 collagen a reliable parameter for predicting the risk of medication-related osteonecrosis of the jaws? A systematic review and meta-analysis of diagnostic test accuracy.

OBJECTIVE: To determine the usefulness of Serum C-terminal telopeptide cross-link of type 1 collagen (sCTX) as a preoperative marker for predicting the risk of developing medication-related osteonecrosis of the jaws (MRONJ) after invasive oral surgery in patients on antiresorptive medication. MATERIALS AND METHODS: Two authors independently searched four electronic databases up to March 25, 2021, for case-control studies and prospective and retrospective cohort studies that assessed preoperative sCTX levels in patients taking antiresorptive medication who underwent oral surgery procedures. The main outcome was the number of MRONJ cases in patients with an sCTX value lower and higher than 150 pg/mL. Qualitative and quantitative data was extracted in tables and the risk of bias was assessed using the QUADAS-2 tool. Estimates of diagnostic accuracy were expressed as sensitivity, specificity, negative and positive likelihood ratio (LR - and LR +), and diagnostic odds ratio (DOR), with a 95% confidence interval (95%CI). The data were combined using random-effects models based on the inverse variance method. RESULTS: Seven studies were included in the meta-analysis. The results were as follows: sensitivity 57% (95%CI: 41-71%), specificity 72% (95%CI: 64-79%), LR + 2 (95%CI: 1.3-3.1), LR - 0.6 (95%CI: 0.4-0.9), and DOR 3.4 (95%CI: 1.5-7.7). CONCLUSIONS: The low overall performance of sCTX indicates that this parameter is not suitable for predicting MRONJ risk in patients on antiresorptive medication who need an oral surgery procedure. CLINICAL RELEVANCE: sCTX should not be considered a reliable preoperative marker to predict MRONJ development.

Third molar surgical difficulty scales: systematic review and preoperative assessment form

Background: The main objective of this systematic review was to collect the pre-existing scales for assessing the difficulty of third molar extraction. The secondary objective was to design a proposal for a preoperative evaluation protocol for the difficulty of third molar extraction. Material and Methods: Two independent researchers conducted an electronic search in Pubmed (MEDLINE), Cochrane, and Scopus databases during March 2021. Included studies evaluated the prediction of the difficulty of surgical removal of impacted upper or lower third molars using new indices/scales or pre-existing scales with or without modifications. Articles referring to coronectomies or assessing pre-surgical difficulty using other tools were excluded. Neither language nor publication date restrictions were applied. Results: Out of 242 articles, 13 prospective cohort studies were finally selected. Seven developed new indices/scales, and 6 assessed the predictive ability of some pre-existing scales. Most of the indices/scales contained radiological variables and few added any patient-related variables. We proposed a preoperative assessment protocol of the difficulty of third molar extraction to facilitate treatment planning and/or considerate referral in cases of high difficulty. This proposal used patient-related, radiological and surgical variables. Conclusions: Using a preoperative protocol to evaluate the surgical difficulty, including different patient-specific, radiological and surgical variables, could facilitate treatment planning, help clinicians prevent complications and assess the possibility of referral.(AU)

Retrospective Cohort Study on the Influence of Bone Remodeling on Marginal Bone Loss and Peri-implantitis Around Immediately Loaded Implants Supporting Complete-Arch Restorations.

PURPOSE: The main objective of this study was to assess the influence of bone remodeling on late marginal bone loss in immediately loaded, implant-supported, complete-arch restorations and, secondarily, to determine its relationship to peri-implant disease occurrence using a multilevel analysis. MATERIALS AND METHODS: A retrospective cohort study of patients treated consecutively in a private clinic with immediately loaded full-arch restorations with at least 12 months of follow-up was conducted. Bone remodeling and marginal bone loss were determined through measurements made on panoramic radiographs by two calibrated examiners. Peri-implant health status was diagnosed in a visit for peri-implant maintenance. Descriptive, bivariate, and multilevel analyses were performed with Stata/IC 15.1 software (StataCorp). RESULTS: A total of 30 patients (11 men and 19 women, mean age: 63.3 ± 10.4 years), with a mean follow-up of 37.7 ± 19.6 months were included. Forty arches (20 maxillary and 20 mandibular) received 207 implants. Bone remodeling had an inversely proportional effect on marginal bone loss (P =.005) but was not related to peri-implantitis (P =.103; hazard rate [HR] = 2.1). CONCLUSION: Taking into account the limitations of this study, bone remodeling around immediately loaded dental implants supporting complete-arch restorations does not appear to increase marginal bone loss or peri-implantitis.

Physicochemical and Biological Characterization of Ti6Al4V Particles Obtained by Implantoplasty: An In Vitro Study. Part I.

Implantoplasty is a mechanical decontamination technique that consists of polishing the supra-osseous component of the dental implant with peri-implantitis. This technique releases metal particles in the form of metal swarf and dust into the peri-implant environment. In the present in vitro study, the following physicochemical characterization tests were carried out: specific surface area, granulometry, contact angle, crystalline structure, morphology, and ion release. Besides, cytotoxicity was in turn evaluated by determining the fibroblastic and osteoblastic cell viability. As a result, the metal debris obtained by implantoplasty presented an equivalent diameter value of 159 µm (range 6-1850 µm) and a specific surface area of 0.3 m2/g on average. The particle had a plate-like shape of different sizes. The release of vanadium ions in Hank's solution at 37 °C showed no signs of stabilization and was greater than that of titanium and aluminum ions, which means that the alloy suffers from a degradation. The particles exhibited cytotoxic effects upon human osteoblastic and fibroblastic cells in the whole extract. In conclusion, metal debris released by implantoplasty showed different sizes, surface structures and shapes. Vanadium ion levels were higher than that those of the other metal ions, and cell viability assays showed that these particles produce a significant loss of cytocompatibility on osteoblasts and fibroblasts, which means that the main cells of the peri-implant tissues might be injured.