Atypical histological presentation of bone regeneration after insertion of cryoprotected allogeneic bone graf / Presentación histológica atípica de la regeneración ósea después de la inserción de un injerto óseo alogénico crioprotegido

Background: To evaluate bone regenerative capacity of cryoprotected corticocancellous allogeneic bone graftperformed in type II and III post-extraction sockets for ridge preservation after twelve weeks in-vivo.Material and Methods: Twenty-seven type II or III bony-walled extraction sockets (mandible and maxilla) wereselected for this study. Following atraumatic tooth-extraction a cryoprotected corticocancellous allogeneic bonegraft material and a resorbable porcine-derived collagen membrane were used for ridge preservation. Duringre-entry surgery at approximately 12 weeks, bone core biopsies were obtained using a 3.2 mm trephine drill andsamples were histologically processed and subjected to qualitative and quantitative histomorphometric analysis.Quantitative data was analyzed using a general linear mixed model with results presented as mean values with thecorresponding 95% confidence interval values. Results: Healing without incident and ridge preservation allowed for the placement of dental implants after 12 weeksin 25 out of the 27 treated socket sites. Analyses yielded an average of ~21.0±7% of old/native bone, ~17±5.5% ofnewly regenerated bone (total of ~38±12.8% for all bone), 0.23±0.14% of new bone presenting with nucleating siteswithin the matrix, ~52±5.12% of soft tissue, and 3.6±2.09% of damaged bone. The average regenerated bone wasstatistically analogous to that of old/native bone (p=0.355). Furthermore, an atypical histological pattern of boneregeneration was observed, with newly formed bone exhibiting “infiltration-like” behavior and with new bone nucle-ating sites observed within the demineralized bone matrix.Conclusions: Cryoprotected corticocancellous allogeneic bone-graft demonstrated osteoconductive, osteoinductive,and osteogenic properties, yielding unique healing patterns which does warrant further investigation.(AU)

Cirugía periapical y regeneración: revisión sistemática / Periapical surgery and regeneration: systematic review

Introducción: Tras un cirugía periapical, suele estar asociado un defecto óseo que puede ser regenerado o no según la literatura. El objetivo es analizar si la regeneración ósea asociada a la cirugía periapical tiene efectos beneficiosos en la curación de los diferentes defectos. Material y Mètodos: Revisión sistemática realizada en Medline-Pubmed, Scopus y Cochrane. Se consideraron criterios PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Ensayos clínicos aleatorizados, estudios de casos y controles, de cohortes y transversales publicados entre enero 2011 y abril 2022, que analizaran el èxito de la cirugía periapical combinada o no con diferentes tècnicas de regeneración ósea, idioma inglès o español, realizados en humanos y adultos (≥16años) fueron incluidos. Resultados: Se incluyeron un total de 8 artículos que analizaban una "n" total de 285 sujetos con 35 abandonos. Se analizan diferentes tipos de lesiones: lesiones transversales, defectos apicomarginales y lesiones periapicales, excepto un estudio que compara las tres. Se utilizan diferentes materiales de regeneración. Se obtuvo un rango de èxito de regeneración ósea entre 81,6% y 93,7%. Discusión: Los avances en equipos de magnificación visual aumento, instrumentos y materiales endodónticos son la razón de un mayor èxito de las cirugías periapicales. Las imágenes en 3D, son valiosas para obtener un mejor diagnóstico del tamaño y tipo de defecto, y planificar así el tratamiento considerando la necesidad de regenerar o no. Aunque los resultados siguen siendo inciertos parece ser que en los defectos transversales y apicomarginales es mejor regenerar, al contrario de los defectos periapicales. (AU)

Introduction: According to the literature, after a periapical surgery there usually remains a bone defect that may be regenerated or not. The aim of this review is to analyse whether bone regeneration associated with periapical surgery is favourable on the healing of different defects. Material and Methods: A systematic review was performed in Medline-Pubmed, Scopus and Cochrane. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria were considered. Randomized clinical trials, case-control, cohort and cross-sectional studies published between January 2011 and April 2022, that analyses the success of periapical surgery associated or not with different bone regeneration techniques, English or Spanish, humans and adults (≥ 16years) studies were included. Results: A total of eightreports were included. They evaluated 285 subjects, with 35 subjects that dropped out. Different types of lesions were analysed in each report: through-and-through lesions, apico-marginal lesions, and periapical lesions, except for one that compared all of them. Different kinds of bone regenerative materials were used. A range of success of between 81,6% and 93,7% of bone regeneration was achieved. Discussion: Improvements in augmentation equipment, instruments, and materials are the reason for the large success of periapical surgery. 3D images are useful to make a better diagnosis of the size and kind of the defect and, in this way, to plan the treatment considering the need to regenerate or not. Although the results remain uncertain, it seems that for through-and-thought and apico-marginal lesions, it is better to regenerate in contrast with periapical lesions. (AU)

Diseño y comparativa de biomateriales para el tratamiento de defectos óseos. Estudio de su comportamiento in vivo en modelo animal de conejo / Desing and comparison of bone substitutes. Study of in vivo behavior in a rabbit model

Objetivo: Comparar in vivo la capacidad de formación ósea de dos tipos de biomateriales diseñados como sustitutivos óseos respecto a autoinjerto de cresta iliaca, uno basado en carbonatohidroxiapatita y otro en vidrio mesoporoso bioactivo. Material y método: Estudio experimental compuesto por 14 conejos de Nueva Zelanda hembras adultas donde se realizó un defecto crítico en hueso radio. La muestra fue dividida en cuatro grupos: defecto sin material, con autoinjerto de cresta iliaca, con soporte de carbonatohidroxiapatita y con soporte de vidrio mesoporoso bioactivo. Se realizaron estudios seriados de radiología simple a las 2, 4, 6 y 12 semanas y estudio de micro-TC a eutanasia a las 6 y 12 semanas. Resultados: En el estudio de radiología simple, el grupo de autoinjerto mostró las mayores puntuaciones de formación ósea (7,5 puntos). Ambos grupos de biomateriales presentaron formación ósea similar (5,3 y 6 puntos, respectivamente) y mayor al defecto sin material (4 puntos), pero siempre menor que el grupo de autoinjerto. Los resultados del estudio de micro-TC mostraron el mayor volumen de hueso en el área de estudio en el grupo de autoinjerto. Los grupos con sustitutivos óseos presentaron mayor volumen de hueso que el grupo sin material, pero siempre menor que en el grupo de autoinjerto. Conclusiones: Ambos soportes parecen favorecer la formación ósea pero no son capaces de reproducir las características del autoinjerto. Por sus diferentes características macroscópicas cada uno podría ser adecuado para un tipo diferente de defecto.(AU)

Aim: Compare bone formation capacity in vivo of two types of biomaterials designed as bone substitutes with respect to iliac crest autograft, one based on carbonate hydroxyapatites and the other one on bioactive mesoporous glass. Materials and methods: Experimental study consisting on 14 adult female New Zeland rabbits where a critical defect was made in the rabbit radius bone. The sample was divided into four groups: defect without material, with iliac crest autograft, with carbonatehydroxyapatite support, and with bioactive mesoporous glass support. Serial X-ray studies were carried out at 2, 4, 6 and 12 weeks and a microCT study at euthanasia at 6 and 12 weeks. Results: In the X-ray study, autograft group showed the highest bone formation scores. Both groups of biomaterials presented bone formation similar and greater than the defect without material, but always less than in the autograft group. The results of the microCT study showed the largest bone volume in the study area in the autograft group. The groups with bone substitutes presented greater bone volume than the group without material but always less than in the autograft group. Conclusion: Both supports seem to promote bone formation but are not capable of reproducing the characteristics of autograft. Due to their different macroscopic characteristics, each one could be suitable for a different type of defect.(AU)

[Translated article] Design and comparison of bone substitutes. Study of in vivo behaviour in a rabbit model / Diseño y comparativa de biomateriales para el tratamiento de defectos óseos. Estudio de su comportamiento in vivo en modelo animal de conejo

Objetivo: Comparar in vivo la capacidad de formación ósea de dos tipos de biomateriales diseñados como sustitutivos óseos respecto a autoinjerto de cresta iliaca, uno basado en carbonatohidroxiapatita y otro en vidrio mesoporoso bioactivo. Material y método: Estudio experimental compuesto por 14 conejos de Nueva Zelanda hembras adultas donde se realizó un defecto crítico en hueso radio. La muestra fue dividida en cuatro grupos: defecto sin material, con autoinjerto de cresta iliaca, con soporte de carbonatohidroxiapatita y con soporte de vidrio mesoporoso bioactivo. Se realizaron estudios seriados de radiología simple a las 2, 4, 6 y 12 semanas y estudio de micro-TC a eutanasia a las 6 y 12 semanas. Resultados: En el estudio de radiología simple, el grupo de autoinjerto mostró las mayores puntuaciones de formación ósea (7,5 puntos). Ambos grupos de biomateriales presentaron formación ósea similar (5,3 y 6 puntos, respectivamente) y mayor al defecto sin material (4 puntos), pero siempre menor que el grupo de autoinjerto. Los resultados del estudio de micro-TC mostraron el mayor volumen de hueso en el área de estudio en el grupo de autoinjerto. Los grupos con sustitutivos óseos presentaron mayor volumen de hueso que el grupo sin material, pero siempre menor que en el grupo de autoinjerto. Conclusiones: Ambos soportes parecen favorecer la formación ósea pero no son capaces de reproducir las características del autoinjerto. Por sus diferentes características macroscópicas cada uno podría ser adecuado para un tipo diferente de defecto.(AU)

Aim: Compare bone formation capacity in vivo of two types of biomaterials designed as bone substitutes with respect to iliac crest autograft, one based on carbonate hydroxyapatites and the other one on bioactive mesoporous glass. Materials and methods: Experimental study consisting on 14 adult female New Zeland rabbits where a critical defect was made in the rabbit radius bone. The sample was divided into four groups: defect without material, with iliac crest autograft, with carbonatehydroxyapatite support, and with bioactive mesoporous glass support. Serial X-ray studies were carried out at 2, 4, 6 and 12 weeks and a microCT study at euthanasia at 6 and 12 weeks. Results: In the X-ray study, autograft group showed the highest bone formation scores. Both groups of biomaterials presented bone formation similar and greater than the defect without material, but always less than in the autograft group. The results of the microCT study showed the largest bone volume in the study area in the autograft group. The groups with bone substitutes presented greater bone volume than the group without material but always less than in the autograft group. Conclusion: Both supports seem to promote bone formation but are not capable of reproducing the characteristics of autograft. Due to their different macroscopic characteristics, each one could be suitable for a different type of defect.(AU)

Efficacy of stem cells in bone rehabilitation in patients with alveolar bone atrophy: a systematic review

Background: Biomedical engineering proposes the use of stem cells as a bone rehabilitation treatment in patients with alveolar bone defects. Many authors suggest that this innovative technique could represent the future of bone regeneration in dentistry. The present study systematically reviewed the efficacy of stem cells in bone regeneration in patients with alveolar bone atrophy. Material and methods: The study was developed following the criteria of the PRISMA guideline (2020). The literature review was conducted in Pubmed, Medline Complete, and Scopus. The search algorithms used the following key words: stem cells, bone regeneration, and alveolar ridge augmentation. To assess the risk of bias, the CASPe methodology was used. Results: Seven clinical trials in humans were included in this systematic review. In all the studies, the proposed objective of bone regeneration by using stem cells was achieved, although in a different way with different results. Although the authors of the analysed clinical trials achieved favourable results, they highlighted the presence of multiple limitations throughout bone regeneration treatments, such as scarce scientific literature on stem cells, a reduced number of follow-up studies, and a lack of a standardized international protocol. Conclusions: Based on the analysed studies, it is concluded that the therapy proposed by tissue engineering through the use of stem cells to rehabilitate patients with bone atrophies can be considered effective. In addition, the need for further studies and standardization of protocols is highlighted. (AU)

El tratamiento con implantes insertados en localizaciones alveolares regeneradas con betafosfato tricalcico / Treatment with implants inserted in regenerated alveolar sites with beta-tricalcium phosphate

Introducción: El objetivo del presente estudio era mostrar los resultados del tratamiento con implantes dentales insertados en área regeneradas con betafosfato tricálcico. Métodos: 48 pacientes con pérdidas dentales parciales fueron tratados con 97 implantes Galimplant ® en área regeneradas con betafofato tricálcico Osteoblast ®. Diversas técnicas fueron realizadas (implantes inmediata en alveolos postextracción; expansión ósea con expansores u osteotomos y elevación transalveolar / lateral del seno maxilar). Los implantes fueron cargados después de un periodo de cicatrización de 6 meses. Resultados: 48 pacientes fueron tratados con implantes, con una edad media de 37,4 años (rango: 22-63 años). En 16 pacientes (33,3%) se realizó la inserción de implantes de forma inmediata en alveolos postextracción. En 9 pacientes (18,7%) se realizó la técnica de expansión ósea con expansores u osteotomos. En 10 pacientes (20,8%) se realizó la elevación transalveolar del seno maxilar. En 13 pacientes (27,1%) la elevación sinusal fué lateral. En la investigación realizada se perdieron 4 implantes de los 97 insertados (4,1%). 2 implantes fueron fracasos inmediatos o precoces (2,06%) ya que se perdieron, durante la fase de cicatrización, al no conseguir la oseointegración. Los 2 fracasos tardíos fueron por periimplantitis (2,06%). La pérdida media de hueso marginal fué de 1,34 ±1,19 mm. Se realizaron un total de 78 prótesis (100%), 61 coronas unitarias (78,2%) y 17 puentes fijos (21,8%). El periodo de seguimiento clínico ha sido de 5 años. Conclusiones: Este estudio indica que los implantes dentales pueden ser insertados con éxito en las áreas regeneradas con betafosfato tricálcico. (AU)

Introduction: The aim of this study was to report the outcome of treatment with dental implants inserted in regenerated sites with beta-tricalcium phosphate. Methods: 48 patients with partial tooth loss were treated with 97 Galimplant ® implants in regenerated sites with beta-tricalcium phosphate Osteoblast ®. Patients were treated with several surgical tecniques (immediate implants in fresh sockets, alveolar ridge expansion, transalveolar /lateral sinus elevation). Implants were loaded after a healing free-loading period of 6 months. Results: 48 patients were treated, with a mean age of 37.4 years (range: 22-63 yr), with 97 implants. Sixteen patients (33.3%) were treated with immediate implants in fresh sockets; in 9 patients (18.7%), alveolar ridge expansion were used; and 10 patients (20.8%) were treated with transalveolar or lateral sinus elevation (13 patients; 27.1%). 2 implants (2,06%) were lost during the healing period and two implant (2,06%) was lost by peri-implantitis. Marginal bone loss was 1.34 ±1.19 mm. A total of 78 prostheses were realized, 61 single crowns (78.2%) and 17 fixed bridges (21.8%). The follow-up period was of 5 years. Conclusions: This study indicate that dental implants can be inserted with success in regenerated sites with beta-tricalcium phosphate. Conclusions: This study indicates that treatment with dental implants placed by transalveolar sinus elevation in geriatric patients constitute an implant treatment with a high success rate. (AU)

Uso de péptidos derivados de la proteína relacionada con la parathormona para aumentar la formación y la regeneración ósea / Use of peptides derived from parathyroid hormone-related protein for increasing bone formation and bone regeneration

Las patologías prevalentes del aparato locomotor como la osteoporosis suponen actualmente un desafío para las sociedades occidentales. La pérdida de masa ósea asociada comúnmente a la edad, especialmente pero no únicamente ligada a la pérdida de estrógenos, aumenta el riesgo de fracturas. En numerosas ocasiones, su reparación está comprometida debido a causas metabólicas del huésped o a la magnitud de la lesión ósea. Esto determina la importancia de estrategias que ayuden a regenerar el hueso dañado, p.e., el uso de factores osteogénicos. Así, se ha propuesto la administración sistémica de la parathormona (PTH), el primer factor anabólico eficaz en el tratamiento de la osteoporosis, que estimula predominantemente la formación ósea en las unidades de remodelado óseo. Recientemente, se ha introducido en la farmacopea un análogo peptídico basado en la secuencia N-terminal de la proteína relacionada con la PTH (PTHrP) (abaloparatida). Este exhibe gran afinidad por el receptor tipo 1 de la PTH y presenta ventajas farmacocinéticas (disminuyendo el riesgo de hipercalcemia) frente a esta hormona en su uso terapéutico en la osteoporosis. Tanto la PTH como la PTHrP N-terminal incrementan la formación del callo de fractura y la integridad del hueso neoformado en modelos animales. Además, el péptido osteostatina derivado de la PTHrP C-terminal, no relacionada con la PTH, presenta propiedades osteogénicas in vitro e in vivo en modelos de osteoporosis. En los últimos años, se ha demostrado que la unión de osteostatina a diversos tipos de implantes (basados en biocerámicas mesoporosas de SiO y biovidrios con Zn) mejora el biomaterial de base para implementar la regeneración ósea. Los datos actuales apoyan a los péptidos derivados de la PTHrP como una estrategia prometedora en aplicaciones de ingeniería tisular ósea. (AU)

Osteoporosis, the most prevalent pathology affecting the skeleton, currently represents a challenge for Western societies. Bone mass loss with age, mainly but not exclusively related to estrogen deficiency, increases fracture risk. Fracture repair is frequently impaired due to metabolic alterations and/or the extention of bone damage. Thus, strategies like use of osteogenic factors that help regenerate damaged bone tissue are highly needed. In this regard, systemic administration of parathormone (PTH) represents the first anabolic treatment in osteoporosis by predominantly increasing bone formation over bone resorption during bone remodeling. Recently, there is a pharmacological alternative to PTH based on a peptide analogue derived from the N-terminal sequence of PTH-related protein (PTHrP) (named abaloparatide). This peptide exhibits great affinity for PTH type 1 receptor, and presents pharmacokinetic advantages (decreasing the risk of hipercalcemia), compared to PTH in the treatment of osteoporosis. N-terminal peptides of both PTH and PTHrP promote the formation of fracture callus and bone healing in animal models of bone injury. In addition, osteostatin peptide derived from the C-terminal tail of PTHrP -unrelated to PTH- displays osteogenic features in vitro and in vivo in osteoporosis models. In recent years, osteostatin loading into various types of implants (including mesoporous bioceramics based on SiO and Zn-doped bioglasses) improves the capacity of the biomaterial to increase bone regeneration. Current data support the notion that PTHrP-derived peptides are a promising strategy for bone tissue engineering applications. (AU)

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)

Bone regeneration at extraction sockets filled with leukocyte-platelet-richfibrin: An experimental pre-clinical study

Background: We aimed to histomorphometrically evaluate the effects of Leucocyte-Platelet-Rich Fibrin (L-PRF),with and without the combination of a bone grafting material, for alveolar ridge preservation using an in vivocanine model.Material and Methods: Seven dogs (Female Beagles, ~18-month-old) were acquired for the study. L-PRF wasprepared from each individual animal by drawing venous blood and spinning them through a centrifuge at 408RCF-clot (IntrasSpin, Intra-Lock, Boca Raton, FL). L-PRF membranes were obtained from XPression fabrication kit (Biohorizons Implant Systems, Inc., AL, USA). A split mouth approach was adopted with the first molarmesial and distal socket defects treated in an interpolated fashion of the following study groups: 1) Empty socket (negative control); 2) OSS filled defect 3) L-PRF membrane; and 4) Mix of Bio-Oss® with L-PRF. After six weeks,samples were harvested, histologically processed, and evaluated for bone area fraction occupancy (BAFO), vertical/horizontal ridge dimensions (VRD and HRD, respectively), and area of coronal soft tissue infiltration.Results: BAFO was statistically lower for the control group in comparison to all treatment groups. Defects treatedwith Bio-Oss® were not statistically different then defects treated solely with L-PRF. Collapsed across all groups,L-PRF exhibited higher degrees of BAFO than groups without L-PRF. Defects filled with Bio-Oss® and Bio-Oss®with L-PRF demonstrated greater maintenance of VRD relative to the control group. Collapsed across all groups,Bio-Oss® maintained the VRD and resulted in less area of coronal soft tissue infiltration compared to the emptydefect. Soft tissue infiltration observed at the coronal area was not statistically different among defects filled withL-PRF, Bio-Oss®, and Bio-Oss® with L-PRF.Conclusions: Inclusion of L-PRF to particulate xenograft did not promote additional bone heading at 6 weeks invivo. ... (AU)

Regeneración ósea guiada con dentina autógena tras la exodoncia de un premolar retenido en posición invertida: evaluación a 4 meses de un caso clínico / Guided bone regeneration with autogenous dentin after extraction of an impacted bicuspidin inverse position: 4-month evaluation of a clinical case

Introducción: el empleo de técnicas regenerativas tras la extracción de dientes retenidos ha mostrado su eficacia con diversos materiales de regeneración, al asociarse al empleo de membranas, pero en los últimos años se ha descrito el empleo de dentina autógena en procedimientos de regeneración ósea, mostrando unos resultados favorables. Caso clínico: se presenta un caso clínico de una mujer de 20 años, sin antecedentes médico-quirúrgicos de interés, que acudió a consulta remitida por su ortodoncista, para la extracción de un premolar maxilar retenido, en posición invertida. Tras la extracción del premolar y del tercer molar inferior retenidos, se obtuvo dentina procedente de ambos, para la regeneración ósea guiada del defecto resultante de la extracción del premolar, realizando revisiones a la semana y a los 4 meses de la intervención. Conclusiones: la dentina autógena demuestra ser un biomaterial biocompatible, adecuado para procedimientos de regeneración ósea guiada, tras la extracción de dientes retenidos, como alternativa a otros biomateriales. (AU)

Introduction: regenerative bone techniques after impacted teeth extraction have shown to be effective with different materials, when used in conjunction with membranes, but in the last few years, autogenous dentin has been used in bone regeneration procedures, having promising results. Clinical case: a clinical case of a 20-year-old woman is presented, with no interesting medical record, who went to dental clinic for removal of an inverse maxillary bicuspid retained. After maxillary bicuspid and lower third molar extractions, autogenous dentin was obtained from both teeth, to perform a guided bone regeneration of the bicuspid defect. A week and 4-month check-up were carried out. Conclusion: autogenous dentin has shown to be a biocompatible material, adequate for guided bone regeneration procedures, after extraction of impacted teeth, as an alternative to other biomaterials. (AU)

Microtomographic reconstruction of mandibular defects treated with xenografts and collagen-based membranes: A pre-clinical minipig model / Reconstrucción microtomográfica de defectos mandibulares tratados con Xenoinjertos y membranas a base de colágeno: un modelo preclínico de minicerdo

Background: The goal of this study was to evaluate hard tissue response following guided bone regeneration us-ing commercially available bovine bone grafts and collagen membranes; bilayer collagen membrane and porcinepericardium-based membrane, by means of a non-destructive three-dimensional (3D) computerized volumetricanalysis following microtomography reconstruction.Material and Methods: Bone regenerative properties of various bovine bone graft materials were evaluated in theGöttingen minipig model. Two standardized intraosseous defects (15mm x 8mm x 8mm) were created bilaterallyof the mandible of eighteen animals (n=72 defects). Groups were nested within the same subject and randomlydistributed among the sites: (i) negative control (no graft and membrane), (ii) bovine bone graft/bilayer collagenmembrane (BOB) (iii) Bio-Oss® bone graft/porcine pericardium-based membrane (BOJ) and (iv) cerabone® bonegraft/porcine pericardium-based membrane (CJ). Samples were harvested at 4, 8, and 12-week time points (n=6animal/time point). Segments were scanned using computerized microtomography (μCT) and three dimensionallyreconstructed utilizing volumetric reconstruction software. Statistical analyses were performed using IBM SPSSwith a significance level of 5% Results: From a temporal perspective, tridimensional evaluation revealed gradual bone ingrowth with the presenceof particulate bone grafts bridging the defect walls, and mandibular architecture preservation over time. Volumetricanalysis demonstrated no significant difference between all groups at 4 weeks (p>0.127). At 8 and 12 weeks therewas a higher percentage of new bone formation for control and CJ groups when compared to BOB and BOJ groups(p<0.039). The natural bovine bone graft group showed more potential for graft resorption over time relative to bo-vine bone graft, significantly different between 4 and 8 weeks (p<0.003)...(AU)

Uso de péptidos derivados de la proteína relacionada con la parathormona para aumentar la formación y la regeneración ósea / Use of peptides derived from parathyroid hormone-related protein for increasing bone formation and bone regeneration

Las patologías prevalentes del aparato locomotor como la osteoporosis suponen actualmente un desafío para las sociedades occidentales. La pérdida de masa ósea asociada comúnmente a la edad, especialmente pero no únicamente ligada a la pérdida de estrógenos, aumenta el riesgo de fracturas. En numerosas ocasiones, su reparación está comprometida debido a causas metabólicas del huésped o a la magnitud de la lesión ósea. Esto determina la importancia de estrategias que ayuden a regenerar el hueso dañado, p.e., el uso de factores osteogénicos. Así, se ha propuesto la administración sistémica de la parathormona (PTH), el primer factor anabólico eficaz en el tratamiento de la osteoporosis, que estimula predominantemente la formación ósea en las unidades de remodelado óseo. Recientemente, se ha introducido en la farmacopea un análogo peptídico basado en la secuencia N-terminal de la proteína relacionada con la PTH (PTHrP) (abaloparatida). Este exhibe gran afinidad por el receptor tipo 1 de la PTH y presenta ventajas farmacocinéticas (disminuyendo el riesgo de hipercalcemia) frente a esta hormona en su uso terapéutico en la osteoporosis. Tanto la PTH como la PTHrP N-terminal incrementan la formación del callo de fractura y la integridad del hueso neoformado en modelos animales. Además, el péptido osteostatina derivado de la PTHrP C-terminal, no relacionada con la PTH, presenta propiedades osteogénicas in vitro e in vivo en modelos de osteoporosis. En los últimos años, se ha demostrado que la unión de osteostatina a diversos tipos de implantes (basados en biocerámicas mesoporosas de SiO y biovidrios con Zn) mejora el biomaterial de base para implementar la regeneración ósea. Los datos actuales apoyan a los péptidos derivados de la PTHrP como una estrategia prometedora en aplicaciones de ingeniería tisular ósea. (AU)

Osteoporosis, the most prevalent pathology affecting the skeleton, currently represents a challenge for Western societies. Bone mass loss with age, mainly but not exclusively related to estrogen deficiency, increases fracture risk. Fracture repair is frequently impaired due to metabolic alterations and/or the extention of bone damage. Thus, strategies like use of osteogenic factors that help regenerate damaged bone tissue are highly needed. In this regard, systemic administration of parathormone (PTH) represents the first anabolic treatment in osteoporosis by predominantly increasing bone formation over bone resorption during bone remodeling. Recently, there is a pharmacological alternative to PTH based on a peptide analogue derived from the N-terminal sequence of PTH-related protein (PTHrP) (named abaloparatide). This peptide exhibits great affinity for PTH type 1 receptor, and presents pharmacokinetic advantages (decreasing the risk of hipercalcemia), compared to PTH in the treatment of osteoporosis. N-terminal peptides of both PTH and PTHrP promote the formation of fracture callus and bone healing in animal models of bone injury. In addition, osteostatin peptide derived from the C-terminal tail of PTHrP -unrelated to PTH- displays osteogenic features in vitro and in vivo in osteoporosis models. In recent years, osteostatin loading into various types of implants (including mesoporous bioceramics based on SiO and Zn-doped bioglasses) improves the capacity of the biomaterial to increase bone regeneration. Current data support the notion that PTHrP-derived peptides are a promising strategy for bone tissue engineering applications. (AU)

A systematic review and meta-analysis on the effectiveness of xenograft to prevent periodontal defects after mandibular third molar extraction / Una revisión sistemática y un metanálisis sobre la eficacia del xenoinjerto para prevenir defectos periodontales después de la extracción del tercer molar mandibular

Background: To evaluate the use of guided bone regeneration with xenograft to prevent periodontal defect in thedistal aspect of the second molar after the surgical removal of the mandibular third molar.Material and Methods: Three electronic databases (Pubmed, Cochrane Library and Scopus) were searched inApril 2020. Randomized clinical trials in non-smokers and healthy patients, with at least six months follow-up, comparing periodontal probing depth, clinical attachment level, alveolar bone level and adverse events wereselected by two independent investigators. The risk of bias assessment of the selected studies was evaluated bymeans of the Cochrane Collaboration’s Tool. Finally, a meta-analysis of the outcomes of interest was performed.Results: Despite 795 articles were found in the initial search, only three randomized controlled clinical trials wereincluded. Pooled results favoured the use of the xenograft plus collagen membrane over the spontaneous healingin terms of periodontal probing depth gain (MD=2.36; 95% CI 0.69 to 4.03; P=0.005) and clinical attachment levelgain (MD=2.52; 95% CI 0.96 to 4.09; P=0.002). No other statistically significant differences were found.Conclusions: Within the limitations of the present review, the xenograft plus collagen membrane exhibited betterperiodontal results than spontaneous healing without increasing postoperative complications. However, future well-designed studies with larger samples are required to confirm our results.(AU)

Efectividad de las células madre mesenquimales en las elevaciones de seno maxilar. Revisión de la literatura / Effectiveness of mesenchymal stem cells in maxillary sinus lift. A literature review

Actualmente, la implantología está considerada como la terapia de elección para rehabilitar dientes ausentes. Sin embargo, debido a diversos factores, no siempre se consigue un enfoque inmediato para la colocación de los implantes. Se debe prestar una atención especial a los sectores maxilares posteriores, que debido al paso del tiempo y a la ausencia de dientes, sufren una gran atrofia alveolar que se encuentra asociada a una expansión del seno maxilar que dificulta, en ocasiones, la rehabilitación con implantes osteointegrados. Debido a esta pérdida ósea, se han desarrollado técnicas quirúrgicas como la elevación de seno maxilar para obtener una ganancia de hueso y poder favorecer la colocación y el pronóstico de los implantes. Sin embargo, existen situaciones en las que incluso esta técnica no aporta un volumen óseo suficiente, siendo preciso acompañarla de técnicas de regeneración ósea.En la actualidad, existen estudios que plantean el uso de células madre mesenquimales en procedimientos de regeneración ósea como alternativa a los procedimientos convencionales.El objetivo del presente trabajo es evaluar a través de la realización de una revisión sistemática de la literatura, la efectividad de las células madres mesenquimales en elevaciones de seno maxilar con diferentes tipos de matriz ósea. (AU)

Currently, implantology is considered the therapy of choice to rehabilitate missing teeth. However, due to various factors, we do not always get an immediate approach to the placement of our implants. Above all, we must pay special attention to the posterior maxillary sectors, which due to the passage of time and the absence of dental pieces suffer great alveolar atrophy associated with an expansion of the maxillary sinus that makes difficult and sometimes impossible the implant therapy. Due to this great bone loss, the professionals have been forced to practice surgical techniques such as maxillary sinus lift to gain bone and to be able to favour the placement and prognosis of the implants. However, there are clinical situations in which even this technique does not give us sufficient bone volume, being necessary a bone regeneration therapy.Thus, thanks to advances in the field of scientific research, various methods have been used to solve this type of problem, but one of the most innovative and current options is bone regeneration using mesenchymal stem cells.This work aims to evaluate, carrying out a systematic review of the literature, the effectiveness of mesenchymal stem cells in maxillary sinus elevations with several types of matrix. (AU)

Regeneración ósea con injertos intraorales: rama vs. mentón. Puesta al día / Bone regeneration with intraoral graft: ramus vs. chin. Updating

La utilización de injertos intraorales en bloque es una alternativa de tratamiento válida para la regeneración en anchura de defectos óseos maxilares y mandibulares. Sin embargo, actualmente no hay consenso entre los diferentes autores en la elección del mejor tipo de bloque intraoral a utilizar. Por ende, esta puesta al día busca comparar la ganancia ósea, la tasa de complicaciones postoperatorias y el éxito del injerto entre bloques autólogos de rama mandibular y mentón. La ganancia ósea alcanzada es similar en ambos bloques. No obstante, se podría deducir una mayor ganancia al utilizar bloques de la rama mandibular cuando son evaluados mediante CBCT. Además, la tasa de reabsorción ósea fue menor con los injertos de rama. La supervivencia de los implantes es equiparable con ambos tipos de injertos. Las complicaciones que tienen lugar, en orden de frecuencia, son las alteraciones sensoriales, las necrosis pulpares, dehiscencias y hemorragias; apareciendo con mayor frecuencia en los bloques de mentón. Además, el periodo de recuperación en las zonas de rama mandibular es más lento. De este modo, a la hora de la elección parece razonable individualizar el caso y tener en consideración aspectos como la morbilidad y el acceso a la zona donante. (AU)

The use of intraoral block grafts is a valid treatment alternative for the regeneration of maxillary and mandibular horizontal bone defects. However, there is currently no consensus among different authors on the choice of the best type of intraoral bone block to use. Therefore, this update seeks to compare bone gain, post-operative complication rate and grafting success between autologous mandibular ramus and chin bone block grafts. The bone gain achieved is similar in both block grafts. However, a higher gain can be observed by CBCT when using mandibular ramus blocks. In addition, the rate of bone resorption is lower with ramus grafts. Implant survival is comparable in both types of grafts. The complications that occur, in order of frequency, are sensory alterations, pulp necrosis, dehiscence and bleeding, appearing more frequently in chin blocks. In addition, the recovery period in the mandibular ramus areas is slower. Thus, when choosing, it seems reasonable to individualize the case and take into consideration aspects such as morbidity and access to the donor area. (AU)

Propiedades osteoinductivas de la dentina en regeneración ósea. Estudio preliminar / Osteoinductive properties of the dentin in bone regeneration. Preliminary study

Introducción: El concepto de preservación alveolar está relacionado con los procedimientos llevados a cabo tras realizar una exodoncia dentaria con el fin de reducir la reabsorción dentro del alvéolo. La dentina ha sido propuesta como un biomaterial para este fin. Este artículo tiene como propósito evaluar la efectividad de la dentina en la preservación alveolar y contrastar sus propiedades. Material y Método: Se presentan como parte de un estudio en desarrollo los primeros casos tras realizar exodoncias múltiples. Determinamos un alveolo de estudio preservado con dentina y un alveolo control en el que estabilizamos el coagulo. La estabilidad dimensional de ambos alveolos se valoró mediante CBCT pasadas 8 y 16 semanas. Tras este periodo colocamos dos implantes experimentales de superficie Bioecth®. A las 16 semanas fueron explantados con trefina y sustituidos por implantes convencionales. Estas muestras fueron analizadas histológica e histomorfomètricamente. Resultados: En el análisis tomográfico apreciamos mayor estabilidad dimensional en el lado estudio. Histológicamente observamos ausencia de células inflamatorias, o signos de reacción a cuerpo extraño, además de partículas de dentina completamente rodeadas de hueso neoformado, y frentes osteogènicos partiendo de partículas de dentina. Discusión: Los resultados obtenidos a partir de este estudio en humanos están en consonancia con lo que ha sido descrito en la literatura. Observamos a nivel tomográfico menor variación dimensional en los alveolos donde se llevó a cabo la preservación con dentina particulada, estos resultados sumados al análisis histológico contrastan las propiedades descritas para injertos particulados de dentina no desmineralizada, biocompatibilidad, osteoconducción y osteoinducción. (AU)

Introduction: The concept of alveolar preservation is related to the procedures carried out after performing a tooth extraction in order to reduce resorption within the alveolus. Dentin has been proposed as a biomaterial for this purpose. The aim of this article is to evaluate the effectiveness of dentin in alveolar preservation and to contrast its properties. Material and Method: The first cases are presented as part of a work in progress study after multiple extractions. It is determined a study socket preserved with dentin and a control socket in which the clot is stabilized.The dimensional stability of both sockets was assessed by CBCT after 8 and 16 weeks. After this period, two experimental Bioecth® surface implants were placed. After 16 weeks these were explanted with trephine and replaced with conventional implants. The samples were analyzed histologically and histomorphometrically. Results: In the tomographic analysis it was observed greater dimensional stability on the study side. It was noted the absence of inflammatory cells, or signs of foreign body reaction in the histology. In addition, dentin particles were completely surrounded by newly formed bone, and appeared osteogenic fronts associated with these particles. Discusion: The results obtained from this study in humans are in line with what has been described in scientific papers. At the tomographic level, it was observed less dimensional variation in sockets where the preservation with particulate dentin was carried out. These results added to the histological análisis, contrast the properties described for particulate grafts of non-demineralized dentin, biocompatibility, osteoconduction and osteoinduction. (AU)

Comparación del Coeficiente de Estabilidad Implantaria ISQ entre implantes colocados en zona antral sobre hueso nativo frente a implantes colocados sobre hueso regenerado / Comparison of the isq implant stability coefficient between implants placed in the antral area on native bone versus implants placed on regenerated bone

El objetivo del estudio es comparar los valores del Coeficiente de Estabilidad Implantaria (ISQ) de implantes colocados en zona antral en hueso nativo frente a los colocados en zona antral en hueso regenerado, para saber si tras tres meses de osteointegración los valores aumentan, ver si son diferentes entre sí según el tipo de hueso y evaluar la relación entre: torque de inserción, tipo de hueso, ISQ obtenido y sus cambios después de la osteointegración. Se trata de un ensayo clínico de propósito analítico, cuya dirección temporal es longitudinal, el inicio del estudio en relación con la cronología de los eventos es prospectivo, existiendo dos grupos de estudio. Los resultados proporcionan evidencias de que los implantes colocados en hueso regenerado, al analizar valores ISQ iniciales, son iguales a los del hueso nativo y, tras la oseointegración, son mayores que los de éstos, pudiendo rehabilitarse esperando el mismo tiempo. CONCLUSIONES: El valor inicial de ISQ es similar en ambos grupos y después de tres meses de osteointegración fue mayor en implantes sobre hueso regenerado. El torque de inserción de implantes en hueso regenerado es mayor que en hueso nativo y existe relación positiva, pero no estadísticamente significativa, entre los valores de ISQ y el torque de inserción. La pérdida ósea marginal de los implantes es similar en ambos grupos y dicha pérdida no está relacionada con los valores de ISQ ni con el torque de inserción obtenido, aunque este hecho puede ser debido a la evaluación a corto plazo

The objectives of the present study are to compare the Implant Stability Quotient (ISQ) values of implants placed in the antral area in native bone versus those placed on regenerated bone, to know whether after three months of osseointegration period the values increase and see if they are different from each other depending on the type of bone and assess the relationship between: insertion torque, type of bone and ISQ obtained an its changes after 3 months of osseointegration.The study design is a Clinical Trial of analytical purpose, whose temporal direction is longitudinal, the beginning of the study in relation to the chronology of the events is prospective. The results provide some evidence in the fact that implants placed in antral zone in regenerated bone, when presenting baseline ISQ values equal to and after osseointegration greater than implants in native bone, could be rehabilitated waiting for the implant. CONCLUSIONS: The initial ISQ value is similar in implants placed in native and regenerated bone and after three months were higher in implants placed in regenerated bone. The insertion torque of the implants placed in regenerated bone is greater than those placed in native bone and there is a positive relationship but not statistically significant between ISQ values and insertion torque. The marginal bone loss of the implants is similar in those placed in native versus regenerated bone and this loss is not related to ISQ values niether to insertion torque obtained. This fact is due to being evaluated in a short period of time

Injerto pediculado palatino en regeneración ósea guiada / Palatal pedicle graft in bone guided regeneration

La regeneración localizada de grandes defectos horizontales en los procesos alveolares, previa a la inserción de implantes dentales, sigue siendo un procedimiento quirúrgico desafiante en cirugía bucal. Entre los procedimientos quirúrgicos más utilizados para tal propósito se encuentran la corticotomía con expansión, injerto en bloque "onlay" y la regeneración ósea guiada (ROG), todos ellos con sus diferentes grados de predictibilidad. El uso de micromalla de titanio en combinación con injertos y sustitutos óseos es un método eficiente para la contención, estabilización y protección de estos injertos, permitiendo así una mejor regeneración de los tejidos. Esta técnica no queda exenta de posibles complicaciones asociadas como pueden ser la infección, necrosis del injerto o exposición de la malla de titanio. En el presente artículo se pretende mostrar la evidencia clínica de la efectividad del uso del colgajo pediculado de rotación palatina como método válido para evitar la exposición de la malla de titanio durante la regeneración ósea guiada

Localized regeneration of large horizontal defects in alveolar processes prior to the insertion of dental implants remains a challenging surgical procedure in oral surgery. Among the most widely used surgical procedures for this purpose are expansion corticotomy, onlay block graft and guided bone regeneration all of them with their different degrees of predictability. The use of titanium micromesh in combination with bone grafts and bone substitutes is an efficient method for the containtment, stabilization and protection of these grafts, thus allowing better tissue regeneration. This technique is not exempt from associated complications such as infection, graft necrosis or exposure of the titanium micromesh.This article aims to show the clinical evidence of the effectiveness of using the palatal rotated pedicle graft as an effective method to avoid exposing the micromesh during guide bone regeneration procedure

Coronectomía en terceros molares inferiores / Coronectomy of the lower third molar

La extracción del tercer molar inferior es el procedimiento más frecuente dentro del campo de la cirugía bucal, siendo el daño del nervio dentario inferior una de las complicaciones más frecuentes en la extracción. Como alternativa para disminuir el riesgo de aparición de esta complicación surge la coronectomía, técnica que consiste en la eliminación de la corona dentaria manteniendo intactas las raíces dentro del hueso alveolar. El objetivo del presente artículo fue realizar una puesta al día sobre la coronectomía en terceros molares inferiores, analizando indicaciones, contraindicaciones, complicaciones y éxito de esta técnica. La coronectomía parece ser una alternativa eficaz a la extracción para la prevención de trastornos neurosensoriales en terceros molares impactados en estrecha relación con el NDI. Sin embargo, es necesaria la realización de más estudios comparando la extracción convencional con la coronectomía, con un mayor seguimiento, para conocer el éxito y las complicaciones a largo plazo de este tratamiento

The lower third molar extraction is one of the most common procedures in the field of oral surgery. Furthermore, the damage of the inferior alveolar nerve is one of the most frequent complications related to this procedure. The coronectomy was introduced in 1984, as an alternative approach that tended to reduce the occurrence of this complication. The main objective of this article is to review current evidence of coronectomy applied to mandibular third molars, analyzing indications, contraindications, complications and success of the technique. The coronectomy seems to be an effective alternative to conventional third molar extraction, for the prevention of neurosensorial disorders in impacted third molars in direct relation with inferior alveolar nerve. However, further studies are needed which compare conventional approach with coronectomy with a greater follow-up to understand the long-term morbidities and success of the technique

Regeneración ósea guiada simultánea en implantes cigomáticos con una aproximación exteriorizada en una atrofia maxilar avanzada / Guided bone regeneration and zygomatic implants: a case report

Se presenta un caso clínico en el que se rehabilita a una paciente con maxilar superior atrófico mediante una combinación de implantes cigomáticos, colocados mediante una aproximación exteriorizada, e implantes anteriores convencionales palatinizados. Se realizó un procedimiento de regeneración ósea guiada alrededor de los implantes cigomáticos para obtener un mayor grosor de la cortical vestibular y palatina alrededor de los implantes del maxilar superior y mejorar el pronóstico. A un año de la carga protésica, el hueso periimplantario se mantiene estable

A clinical case is presented in which a patient with atrophic upper jaw is rehabilitated by a combination of zygomatic implants, placed using an exteriorized approach, and conventional palatalized anterior implants. A guided bone regeneration procedure is performed around the zygomatic implants to obtain a greater thickness of the facial bone and improve the prognosis. One year after loading, the peri-implant bone remains stable