Peri-implantitis experimental. Etiología y tratamiento

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Odontología, leída el 12/02/2021. Tesis formato europeo (compendio de artículos)Peri-implantitis is a chronic inflammatory disease caused by bacteria resulting in peri-implant tissue inflammation and bone loss. Several factors such as the implantabutment connection or the implant surface are known to be closely related to the maintenance of peri-implant bone levels. Different implant to abutment configurations, such as platform switching have shown to facilitate bone stability by providing extra space for the peri-implant soft tissue seal. However, its influence on the initiation and progression of peri-implantitis remains unclear. Similarly, innovations in the chemical composition of the implant surface have shown a stronger bond between the implant and the surrounding bone. However, whether this covalent bonding may as well provide increased protection against bacterial challenge and hence, a lesser incidence of periimplantitis, is still unknown. With current regenerative surgical interventions, re-osseointegration of a previously contaminated implant surface has been shown to be possible, although its predictability has not been demonstrated. Growth factors such as bone morphogenetic proteins have demonstrated osteogenic activity when used in bone regenerative interventions, mainly when used in sinus lifting and lateral bone augmentation procedures. However, studies using BMP-2 aiming for re-osseointegration of periimplantitis bone defects have showed conflicting results. Objectives: The objectives of this series of investigations were: a) to evaluate the degree of bone regeneration and re-osseointegration when combining a xenogeneic bone replacement graft plus rhBMP-2 and a collagen membrane in ligature induced periimplantitis osseous defects in dogs (study 1); b) to evaluate the rate of bone loss progression during experimentally induced peri-implantitis using two different implantabutment connections in implants with identical surface topography (study 2); c) to evaluate the influence of modifying the implant surface by adding a monolayer of multiphosphonate molecules on de-novo bone formation and osseointegration (study 3); and d) to evaluate the susceptibility to bone loss of a novel multi-phosphonate implant surface treatment during experimental peri-implantitis (study 4)...La peri-implantitis es una enfermedad inflamatoria crónica causada fundamentalmente por bacterias, que produce inflamación y pérdida de hueso periimplantaria. Diferentes factores como el tipo de conexión entre el pilar y el implante o las características de superficie influyen directamente en el mantenimiento de los niveles óseos peri-implantarios. Un tipo de conexión implante-pilar conocida como “cambio de plataforma” ha demostrado mayor estabilidad del hueso peri-implantario gracias al espacio extra que proporciona a los tejidos blandos y su consiguiente sellado mucoso alrededor del implante. Sin embargo, el papel que juega en el inicio y progresión de la peri-implantitis sigue sin estar claro. De forma similar, innovaciones en la composición química de la superficie implantaria han demostrado proporcionar una unión más íntima entre el implante y el hueso. Sin embargo, el hecho de que dicho incremento en el contacto entre el hueso y el implante proporcione mayor protección frente a la periimplantitis sigue siendo una incógnita. Mediante los procedimientos de cirugía regenerativa actuales es posible conseguir re-oseointegración de una superficie previamente contaminada, sin embargo, dicha reoseointegración sigue siendo impredecible y difícil de obtener de forma completa. En este sentido, factores de crecimiento como las proteínas morfogenéticas han demostrado incrementar la capacidad osteogénica de procedimientos como la elevación de seno maxilar o el aumento horizontal de cresta. Sin embargo, los estudios que evalúan la capacidad de la BMP-2 en el incremento de la reoseointegración han arrojado resultados contradictorios. Objetivos: Los objetivos de esta serie de estudios fueron: a) evaluar el grado de regeneración ósea y re-oseointegración mediante la utilización de una combinación de un sustituto óseo xenogénico junto a rhBMP-2 y una membrana de colágeno en defectos óseos producidos tras peri-implantitis experimental (estudio 1); b) evaluar la pérdida ósea a lo largo del proceso de peri-implantitis experimental usando dos tipos de conexión implante-pilar diferentes en implantes con la misma superficie (estudio 2); 3) evaluar la influencia de la modificación de la superficie peri-implantaria mediante la adición de una monocapa de fosfonatos en la oseointegración (estudio 3); y 4) evaluar la susceptibilidad de esta nueva superficie en el desarrollo de la peri-implantitis experimental (estudio 4)...Fac. de OdontologíaTRUEunpu

Regeneration of alveolar bone defects in the experimental pig model: A systematic review and meta-analysis.

OBJECTIVE Pigs are emerging as a preferred experimental in vivo model for bone regeneration. The study objective was to answer the focused PEO question: in the pig model (P), what is the capacity of experimental alveolar bone defects (E) for spontaneous regeneration in terms of new bone formation (O)? METHODS Following PRISMA guidelines, electronic databases were searched for studies reporting experimental bone defects or extraction socket healing in the maxillae or mandibles of pigs. The main inclusion criteria were the presence of a control group of untreated defects/sockets and the assessment of regeneration via 3D tomography [radiographic defect fill (RDF)] or 2D histomorphometry [new bone formation (NBF)]. Random effects meta-analyses were performed for the outcomes RDF and NBF. RESULTS Overall, 45 studies were included reporting on alveolar bone defects or extraction sockets, most frequently in the mandibles of minipigs. Based on morphology, defects were broadly classified as 'box-defects' (BD) or 'cylinder-defects' (CD) with a wide range of healing times (10 days to 52 weeks). Meta-analyses revealed pooled estimates (with 95% confidence intervals) of 50% RDF (36.87%-63.15%) and 43.74% NBF (30.47%-57%) in BD, and 44% RDF (16.48%-71.61%) and 39.67% NBF (31.53%-47.81%) in CD, which were similar to estimates of socket-healing [48.74% RDF (40.35%-57.13%) and 38.73% NBF (28.57%-48.89%)]. Heterogeneity in the meta-analysis was high (I2  > 90%). CONCLUSION A substantial body of literature revealed a high capacity for spontaneous regeneration in experimental alveolar bone defects of (mini)pigs, which should be considered in future studies of bone regeneration in this animal model

De novo bone formation around implants with a surface based on a monolayer of multi‐phosphonate molecules. An experimental in vivo investigation

Objectives: The purpose of this experimental in vivo investigation was to evaluate the influence of modifying the implant surface by adding a monolayer of multiphosphonate molecules on the de novo bone formation and osseointegration. Material and Methods: The study was designed as an animal preclinical trial with intra-animal control and two healing periods, 2 and 8 weeks, to compare implants with an identical macro-design but with two different surfaces. Eight female Beagle dogs participated in the study. Control implants had a moderately rough surface combining sandblasting and acid etching; test implants had an additional monophosphonate layer covalently bonded to titanium. Histologic and radiographic (micro-CT) outcome variables were evaluated. Results: The first bone-to-implant contact (fBIC) was located more coronally for the test implants at the first (0.065 mm (95% CI = −0.82, 0.60)) and second healing milestones (0.17 mm (95% CI = −0.9, 0.55)). Most coronal BIC of the test implants displayed a higher percentage of osseointegration, +6.33% and +13.38% after 2 and 8 weeks, respectively; however, the differences were not statistically significant. The micro-CT examination did not show any BIC difference. Conclusions: The monophosphonate layer coating demonstrated clinical, histological, and radiographic results similar to the control surface

Hard and soft tissue healing around implants with a modified implant neck configuration: an experimental in vivo preclinical investigation.

Objectives: To evaluate the dimensions and morphology of the peri-implant tissues around a modified dental implant designed with a tissue level connection and a convergent transmucosal neck.This test implant was compared with a conventional bone level implant connected to a cylindrical machined titanium abutment. Material and methods: Eight experimental animals were used for this in vivo investigation, where 16 test and 16 control implants were placed following a random allocation sequence. The following histological outcomes were evaluated 4 and 12 weeks after implantation: the morphology of peri-implant tissues, the soft tissue height and thickness, the horizontal and vertical bone remodeling and the bone to implant contact (BIC). Results: In both early (4 weeks) and late (12 weeks) healing times, there were no statistically significant differences between test and control implants, with respect to the overall height and thickness of the peri-implant hard and soft tissues. There was a tendency toward a more coronal free gingival margin (I-FGM) at the buccal aspect of test when compared to control implants (at 4 weeks, difference of 0.97mm (p=0.572) and 0.30mm (p=1.000) at 12 weeks). Similarly, there was a tendency toward a more coronal position of the first bone to implant contact (I-B) at the buccal aspect of test as compared to control implants (1.08mm (p=0.174) at 4 weeks and 0.83mm (p=0.724) at 12 weeks)

Cell Therapy Based on Gingiva-Derived Mesenchymal Stem Cells Seeded in a Xenogeneic Collagen Matrix for Root Coverage of RT1 Gingival Lesions: An In Vivo Experimental Study

(1) Background: To investigate the effect of a xenogeneic collagen matrix (CMX) seeded with autologous gingiva-derived mesenchymal cells (GMSCs) when combined with a coronally advanced flap (CAF) in the treatment of localized gingival recession type 1 (RT1). (2) Methods: Dehiscence-type defects were created in seven dogs. GMSCs were isolated, transfected with a vector carrying green fluorescent protein (GFP) and expanded. Once chronified, the defects were randomly treated with (1) CAF plus the combination of CMX and GFP+ GMSCs, (2) CAF plus CMX with autologous fibroblasts, (3) CAF plus CMX and (4) CAF alone. Histological and clinical outcomes at 2- and 6-week healing periods were analyzed and compared among groups. (3) Results: Histologically, the addition of autologous cells to the CMX resulted in reduced inflammation and a variable degree of new cementum/bone formation. CMX plus GMSCs resulted in greater mean recession reduction (1.42; SD = 1.88 mm) and percentage of teeth with recession reduction of ≥2 mm (57%) when compared to the other groups, although these differences were not statistically significant. (4) Conclusions: The histometric and clinical results indicated a positive trend favouring the combination of CMX and GMSCs with the CAF when compared to the groups without cells, although these differences were not statistically significant

Immunohistochemical comparison of lateral bone augmentation using a synthetic TiO2 block or a xenogeneic graft in chronic alveolar defects

Objectives To evaluate osteogenic markers and alveolar ridge profile changes in guided bone regeneration (GBR) of chronic non-contained bone defects using a non-resorbable TiO2 block. Material and methods Three buccal bone defects were created in each hemimandible of eight beagle dogs and allowed to heal for 8 weeks before GBR. Treatment was assigned by block randomisation: TiO2 block: TiO2-scaffold and a collagen membrane, DBBM particulates: Deproteinised bovine bone mineral (DBBM) and a collagen membrane, Empty control: Only collagen membrane. Bone regeneration was assessed on two different healing timepoints: early (4 weeks) and late healing (12 weeks) using several immunohistochemistry markers including alpha smooth muscle actin (α-SMA), osteopontin, osteocalcin, tartrate-resistant acid phosphatase and collagen type I. Histomorphometry was performed on Movat Pentachrome and Von Kossa/Van Gieson stained sections. Stereolithographic models were used to compare alveolar profile changes. Results The percentage of α-SMA and osteopontin increased in TiO2 group after 12 weeks of healing at the bone-scaffold interface, while collagen type I increased in the empty control group. In the defect area, α-SMA decreased in the empty control group, while collagen type I increased in the DBBM group. All groups maintained alveolar profile from 4 to 12 weeks, but TiO2 group demonstrated the widest soft tissue contour profile. Conclusions The present findings suggested contact osteogenesis when GBR is performed with a TiO2 block or DBBM particulates. The increase in osteopontin indicated a potential for bone formation beyond 12 weeks. The alveolar profile data indicated a sustained lateral increase in lateral bone augmentation using a TiO2 block and a collagen membrane, as compared to DBBM and a collagen membrane or a collagen membrane alone

Peri-Implant Health and the Knowing-Doing Gap : A Digital Survey on Procedures and Therapies

Objectives: Peri-implant tissue maintenance and treatment is becoming a serious challenge in implantology. With increasing numbers of implants being placed, more cases of peri-implant mucositis and peri-implantitis is seen. A digital survey on peri-implant disease management was issued to experts in periodontology and implantology to identify the tools and procedures most commonly used today to treat peri-implant diseases and successfully manage peri-implant health. The primary aim was to assess whether there is consensus in the choice of treatment to manage peri-implant diseases and to prevent their recurrence once treated. The secondary aim was to obtain insight into future protocols and /or devices, and the research and development needed. Materials and Methods: Participants in this digital survey were professionals specialising in periodontology, oral surgery, and implant dentistry. The questionnaire included both a series of closed- and open-ended questions. A total of 16 countries participated. The survey was sent by e-mail to 70 individuals, 66 received the survey and 37 of receivers responded, two of the participants were excluded due to insufficient filling of the survey. In the end 35 respondents completed the survey. Results: Respondents agree that the efficacy of mechanical and chemical decontamination of implant surfaces needs to be improved and better documented. It is a common opinion that the current remedies, mostly adapted from periodontal practises, do not provide effective and reliable clinical outcomes when treating peri-implant ailments. There is a general agreement amongst experts that regularly scheduled (3–6-month intervals) maintenance treatments are essential for maintaining peri-implant health in patients experiencing implant complications. Respondents are also concerned about unnecessary use of systemic antibiotics for managing peri-implant health. Conclusion: Regardless of agreements in parts, there was no observed consensus on the most effective treatment options for treating peri-implantitis. The experts all agree it is an urgent need for well-designed, long-term follow-up randomised and controlled clinical trials comparing interventions to provide an evidence-based strategy for peri-implant health management

Peri-Implant Health and the Knowing-Doing Gap—A Digital Survey on Procedures and Therapies

Objectives: Peri-implant tissue maintenance and treatment is becoming a serious challenge in implantology. With increasing numbers of implants being placed, more cases of peri-implant mucositis and peri-implantitis is seen. A digital survey on peri-implant disease management was issued to experts in periodontology and implantology to identify the tools and procedures most commonly used today to treat peri-implant diseases and successfully manage peri-implant health. The primary aim was to assess whether there is consensus in the choice of treatment to manage peri-implant diseases and to prevent their recurrence once treated. The secondary aim was to obtain insight into future protocols and /or devices, and the research and development needed. Materials and Methods: Participants in this digital survey were professionals specialising in periodontology, oral surgery, and implant dentistry. The questionnaire included both a series of closed- and open-ended questions. A total of 16 countries participated. The survey was sent by e-mail to 70 individuals, 66 received the survey and 37 of receivers responded, two of the participants were excluded due to insufficient filling of the survey. In the end 35 respondents completed the survey. Results: Respondents agree that the efficacy of mechanical and chemical decontamination of implant surfaces needs to be improved and better documented. It is a common opinion that the current remedies, mostly adapted from periodontal practises, do not provide effective and reliable clinical outcomes when treating peri-implant ailments. There is a general agreement amongst experts that regularly scheduled (3–6-month intervals) maintenance treatments are essential for maintaining peri-implant health in patients experiencing implant complications. Respondents are also concerned about unnecessary use of systemic antibiotics for managing peri-implant health. Conclusion: Regardless of agreements in parts, there was no observed consensus on the most effective treatment options for treating peri-implantitis. The experts all agree it is an urgent need for well-designed, long-term follow-up randomised and controlled clinical trials comparing interventions to provide an evidence-based strategy for peri-implant health management