Hard tissue volumetric and soft tissue contour linear changes at implants with different surface characteristics after experimentally induced peri-implantitis: an experimental in vivo investigation.

OBJECTIVE: To evaluate the hard tissue volumetric and soft tissue contour linear changes in implants with two different implant surface characteristics after a ligature-induced peri-implantitis. MATERIAL AND METHODS: In eight beagle dogs, implants with the same size and diameter but distinct surface characteristics were placed in the healed mandibular sites. Test implants had an external monolayer of multi-phosphonate molecules (B+), while control implants were identical but without the phosphonate-rich surface. Once the implants were osseointegrated, oral hygiene was interrupted and peri-implantitis was induced by placing subgingival ligatures. After 16 weeks, the ligatures were removed and peri-implantitis progressed spontaneously. Bone to implant contact (BIC) and bone loss (BL) were assessed three-dimensionally with Micro-Ct (µCT). Dental casts were optically scanned and the obtained digitalized standard tessellation language (STL) images were used to assess the soft tissue vertical and horizontal contour linear changes. RESULTS: Reduction of the three-dimensional BIC percentage during the induction and progression phases of the experimental peri-implantitis was similar for both the experimental and control implants, without statistically significant differences between them. Soft tissue analysis revealed for both implant groups an increase in horizontal dimension after the induction of peri-implantitis, followed by a decrease after the spontaneous progression period. In the vertical dimension, a soft tissue dehiscence was observed in both groups, being more pronounced at the buccal aspect. CONCLUSIONS: The added phosphonate-rich surface did not provide a more resistant environment against experimental peri-implantitis, when assessed by the changes in bone volume and soft tissue contours. CLINICAL RELEVANCE: Ligature-induced peri-implantitis is a validated model to study the tissue changes occurring during peri-implantitis. It was hypothesized that a stronger osseointegration mediated by the chemical bond of a phosphonate-rich implant surface would develop an environment more resistant to the inflammatory changes occurring after experimental peri-implantitis. These results, however, indicate that the hard and soft tissue destructive changes occurring at both the induction and progression phases of experimental peri-implantitis were not influenced by the quality of osseointegration.

Experimental peri-implantitis around titanium implants with a chemically modified surface with a monolayer of multi-phosphonate molecules: a preclinical 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 multi-phosphonate molecules on the development of experimental peri-implantitis. MATERIAL AND METHODS: Eight beagle dogs received 5 tests and 5 control implants each following a split-mouth design 3 months after premolar and molar extraction. On the most mesial implant of each side, a 3-mm buccal dehiscence was artificially created. Experimental peri-implantitis was induced by silk ligatures over a 4-month period; after ligature removal, peri-implantitis was left to progress for another 4 months without plaque control. Clinical, histological, and radiographic outcomes were evaluated. RESULTS: Radiographically, both implant groups showed a similar bone loss (BL) at the end of the induction and progression phases. BL measured on the histological sections of the test and control groups was 3.14 ± 0.42 mm and 3.26 ± 0.28 mm, respectively; the difference was not statistically significant (p > 0.05). The remaining buccal bone to implant contact (bBIC) percentage of the test and control groups was 59.38 ± 18.62 and 47.44 ± 20.46%, respectively; the difference, however, was not statistically significant (p > 0.05). Bone loss observed at dehiscent sites compared to non-dehiscent ones showed no statistically significant difference (p > 0.05). CONCLUSIONS: Addition of a monophosphonate layer to a moderately rough implant surface did not affect development of experimental peri-implantitis. CLINICAL RELEVANCE: Influence of implant surface on peri-implantitis may condition implant selection by the clinician, especially on patients with disease risk factors. In that sense, monophosphate layer implants do not show higher peri-implantitis risk than control implants.

Alveolar crest contour changes after guided bone regeneration using different biomaterials: an experimental in vivo investigation.

OBJECTIVE: To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects around implants. MATERIAL AND METHODS: Chronic alveolar ridge defects were created bilaterally in the mandible of eight Beagle dogs. Once implants were placed, three treatment groups were randomly allocated to each peri-implant dehiscence defect: (i) test group received a bone substitute composed of hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) covered by a cross-linked collagen membrane, (ii) positive control group with placement of deproteinized bovine bone mineral (DBBM) plus a porcine natural collagen membrane, and (iii) a negative control with no treatment. Two healing periods (8 and 16 weeks) were evaluated. Dental casts were optically scanned, the obtained files were uploaded into an image analysis software and superimposed to evaluate the linear changes. RESULTS: In both healing periods, the gains in linear contours were higher in the test group and at the intermediate level (3 mm below the gingival margin). While at 8 weeks, no significant differences were found between the groups; at 16 weeks, the test and positive control groups demonstrated significant gains in contour compared with negative control. CONCLUSIONS: GBR using different biomaterials significantly increased the buccal contours of the alveolar crest when used at dehiscence defects around dental implants. CLINICAL RELEVANCE: Particulate highly porous synthetic bone substitute and a cross-linked collagen membrane demonstrated similar outcomes in terms of contour augmentation when compared to bovine xenograft (DBBM) and a collagen membrane.

Contour changes after guided bone regeneration of large non-contained mandibular buccal bone defects using deproteinized bovine bone mineral and a porcine-derived collagen membrane: an experimental in vivo investigation.

OBJECTIVE: The objective of this study was to evaluate soft tissue contour changes after three different regenerative therapies in chronic ridge defects. MATERIAL AND METHODS: Buccal bone defects were created in the mandible of nine beagle dogs. Augmentation procedures were performed 3 months later using a bone replacement graft (BRG), resorbable collagen membrane (MBG), or a combination of both procedures (CBG). Silicone impressions were taken before tooth extraction (T1), before the augmentation procedure (T2), and 3 months after the regenerative surgeries (T3). Casts were optically scanned and stereolithography files were superimposed to analyze the horizontal changes in ridge contours. RESULTS: After defect creation, most part of the horizontal changes occurred 4 and 6 mm below the gingival margin. In the mesial defect (D1) at T3, the mean horizontal gain in MBG amounted to 0.47 ± 0.34 mm, 0.79 ± 0.67 mm in the BRG, and 0.87 ± 0.69 mm for the CBG. In the middle defect (D2), the mean changes for the MBG were 0.11 ± 0.31, 1.01 ± 0.91 for the BRG, and 0.98 ± 0.49 for the CBG. The mean changes in the distal defect (D3) amounted to 0.24 ± 0.72 for the MBG, 1.04 ± 0.92 for the BRG, and 0.86 ± 0.56 for the CBG. The differences reached significance in all defects for the comparison MBG-BRG and MBG-CBG, while similar parameters were observed for the comparison BRG-CBG. CONCLUSION: BRG and CBG were equally effective and superior to MBG in increasing the horizontal tissue contours. The augmentation seldom reached the values before extraction. CLINICAL RELEVANCE: Scaffolding materials are needed for contour augmentation when using resorbable collagen membranes.

Radiological evaluation of the Cresco system in combination with Osseospeed implants: a preliminary 3-year report.

AIM: In this preliminary study, the 3-year radiological outcomes of Osseospeed implant-supported fixed complete or partial prostheses made with two different laboratory protocols were compared. METHODS: A convenience sample of 34 patients, who were either partially or completely edentulous in either jaw, were randomly assigned to two groups, of 17 patients each, using either a traditional laboratory protocol (control group) or the Cresco one (test group). The study's objective was an assessment of marginal bone loss around implants, measured on intraoral radiographs at 3-year follow-up. RESULTS: None of the implants inserted was lost during the study and radiological measurements of marginal bone level changes revealed that the mean marginal bone loss was respectively 0,73±0,33mm for test group and 0,88±1,13mm for control group. The differences between test and control groups were not statistically significant. CONCLUSION: This preliminary study did not demonstrate statistically significant differences in marginal bone loss around implant-prostheses prepared with the two different laboratory protocols, over the 3-year observational period.

Periodontal regeneration following implantation of cementum and periodontal ligament-derived cells.

BACKGROUND AND OBJECTIVE: The periodontal regeneration of bone defects is often unsatisfactory and could be largely improved by cell therapy. Therefore, the purpose of this study was to evaluate the regenerative potential of implanting canine cementum-derived cells (CDCs) and canine periodontal ligament-derived cells (PDLDCs) in experimentally created periodontal intrabony defects in beagle dogs. MATERIAL AND METHODS: Cells were obtained from premolars extracted from four beagle dogs. Three-wall intrabony periodontal defects, 3 mm wide and 4 mm deep, were surgically created in their second and fourth premolars and plaque was allowed to accumulate. Once the defects were surgically debrided, periodontal regeneration was attempted by random implantation of collagen sponges embedded with 750,000 CDCs, 750,000 PDLDCs or culture medium. After 3 mo of healing, specimens were obtained and periodontal regenerative outcomes were assessed histologically and histometrically. RESULTS: The histological analysis showed that a minimal amount of new cementum was formed in the control group (1.56 ± 0.39 mm), whereas in both test groups, significantly higher amounts of new cementum were formed (3.98 ± 0.59 mm in the CDC group and 4.07 ± 0.97 mm in the PDLDC group). The test groups also demonstrated a larger dimension of new connective tissue, resulting in a significantly more coronal level of histological attachment. CONCLUSION: This proof-of-principle study suggests that cellular therapy, in combination with a collagen sponge, promoted periodontal regeneration in experimental intrabony periodontal defects.

Tratamiento quirúrgico vs terapia periodontal básica: estudios longitudinales en periodoncia clínica / Periodontal surgery vs cause-related periodontal therapy: longitudinal study in clinical periodontology

Las enfermedades periodontales son unas graves infecciones bacterianas que destruyen las fibras de inserción y el hueso de soporte que mantienen los dientes en la boca. Sin tratar, esta enfermedad puede llevar a la pérdida dental (Medical Dictionary). Los estudios longitudinales han centrado su atención hacia la periodontitis crónica. Se ha documentado el decisivo papel de la placa bacteriana en la iniciación y en el mantenimiento de la gingivitis, y que, los efectos dañinos sobre los tejidos y la gravedad de estos efectos están regulados por una compleja interacción entre el parásito y huésped. El tratamiento de la lesión periodontal cumple, para el tratamiento periodontal básico, con el propósito de eliminar y prevenir la recurrencia de los depósitos bacterianos localizados en las superficies dentarias supra gingivales y subgingivalesy, para el tratamiento quirúrgico con el objetivo de crear acceso para el desbridamiento profesional correcto de las superficies radiculares infectadas y establecer una morfología gingival adecuada que facilite el autocontrol de la placa por parte del paciente. Diferentes técnicas se han utilizado para alcanzar el objetivo de mejorar el pronóstico de los dientes a largo plazo. Desafortunadamente no son muchos los estudios que consiguen demostrar la efectividad de las técnicas utilizadas, con una evolución a lo largo del tiempo dejando entonces algunas incertidumbres (AU)

Periodontal diseases are bacterial infections that destroy the attachment fibres and supporting bone that hold the teeth in the mouth. Left untreated, these diseases can lead to tooth loss (Medical Dictionary). Longitudinal studies centred their attention on chronic periodontitis. It has been documented the decisive role played by microbiological plaque in the initiation of gingivitis and that, the harmful effect on the tissues and its severity, are controlled by the complex host-parasite interaction. Treatment of periodontal lesion can be carried out either by non-surgical treatment, to eliminate and prevent the recurrence of bacterial deposits, or by surgical treatment, to create access for professional debridment of infected root surface and establish adequate gingival morphology to facilitate self-plaque control. Different techniques are used to achieve the objective to improve teeth long term prognosis. Unfortunately no many studies have been able to demonstrate the effectiveness of the used technique in a long term intervals leaving unclear some questions (AU)

Papel etiológico de los virus en la enfermedad periodontal / Etiologic role of virus in periodontal disease

El objetivo de esta revisión es presentar la evidencia disponible que relaciona la infección por virus con el desarrollo de periodontitis. Esta relación se ha visto con los virus de la familia herpes, sobretodo el citomegalovirus humano (CMV) y el virus Epstein-Barr (VEB), así como con el virus de la inmunodeficiencia humana (HIV). Las infecciones por herpesvirus generalmente sucede en dos fases, durante la primoinfección la clínica suele ser leve o asintomática y a esta le sigue una fase asintomática en la que el virus se encuentra en estado de latencia. Dicho estado se verá interrumpido esporádicamente por periodos de activación en los que se produce una replicación viral y posiblemente se dé una manifestación de la enfermedad que explicaría, en parte, el progreso en episodios de la enfermedad periodontal . De hecho, algunas de las causas que llevan a la reactivación del virus también se consideran factores de riesgo de la enfermedad periodontal y podrían relacionar a ambas patologías (AU)

The purpose of this review is to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis. This relationship has been found mainly with the herpesvirus family, especially with human cytomegalovirus (CMV) and with Epstein-Barr virus (EBV), but also with human immunodeficiency virus (HIV). The herpesvirus infection generally involves a mild or asymptomatic primary phase followed by an asymptomatic latent phase interrupted sporadically by periods of activation, where viral replication and possibly clinical disease become manifest and which will in part, explain the episodic progressive nature of human periodontitis. In fact, herpesvirus reactivation is triggered by a number of immunosuppressing factors, some of which have also been shown to be risk indicators of periodontal disease and which could relate both pathologies (AU)

Ameloblastoma plexiforme del maxilar: manejo quirúrgico y protético. A propósito de un caso / Plexiform ameloblastoma in the maxilla: surgical and prosthetic management. With reference to one case

El ameloblastoma es un tumor odontógeno benigno de derivación epitelial, de elevada invasión local, crecimiento intermitente y con alta probabilidad de recidiva. Puede dividirse en los siguientes tipos histológicos: folicular, plexiforme, acantomatoso, a células basales y granulares. El ameloblastoma folicular es el subtipo histológico más común. Se manifiesta prevalentemente durante la tercera, cuarta y quinta década de vida, sin predilección para el sexo, aun así se puede encontrar en cualquier grupo de edad incluyendo niños. La mayoría de los ameloblastomas se encuentra sobretodo en mandíbula (al nivel del ángulo y rama). Las características clínicas, incluso si complementadas con radiografías y muestras histológicas, no son útiles a la hora de predeterminar el comportamiento biológico y por lo tanto el pronóstico de un ameloblastoma individual. Los autores presentan un caso localizado de ameloblastoma plexiforme localizado en la parte posterior del maxilar de un hombre de 30 años; el término "plexiforme" se refiere al aspecto de anastomosis de los islotes del epitelio odontógeno, en contraste con el tipo «folicular». En este artículo se discuten importantes aspectos de la patología, del tratamiento quirúrgico y protésico. En conclusión, es necesaria una cooperación estricta a largo plazo de un grupo de clínicos, patólogos, cirujanos y prostodoncistas, para ofrecer el mejor tratamiento individualizado en cada caso (AU)

The ameloblastoma is a clinically persistent benign tumor derived from odontogenic epithelium, locally invasive, intermittent in growth and with high a probability of recurrence. The following histologic patterns may be distinguished: follicular, plexiform, spindle cell, acanthomatous, basal cell type and granular cell. The follicular ameloblastoma is the most common histologic tipe. The majority of patients are in 3th, 4th and 5th decade, but can be found in any age group including children. The majority of ameloblastomas are observed in the mandible (mostly angle or ramus). Clinical features, even if combined with radiology or histology findings, are not useful when trying to determine the biological behaviour and therefore the prognosis of an individual ameloblastoma. The authors report a case of plexiform ameloblastoma in the posterior maxilla, in male 30 year old otherwise healthy; the term “plexiform” refers to the appearance of anastomosing islands of odontogenic epithelium in contrast to a follicular pattern. Important questions on pathology, surgical and prosthetic therapy are discussed in this paper. In conclusion, a close cooperation of clinicians, pathologists, surgeons and prosthesis’s is necessary and very important over a long period of time for the best management of each individual case (AU)

Extracciones dentarias en pacientes en tratamiento con anticoagulantes: revisión de la literatura / Dental extractions in patients under anticoagulant therapy: a literature review

Objetivo del trabajo. En pacientes en terapia con anticoagulantes orales, una simple extracción puede provocar hemorragias importantes. En la literatura se describen dos enfoques terapéuticos en casos de intervenciones quirúrgicas en esta categoría de pacientes. Uno propone la reducción de la dosis terapéutica del fármaco, mientras que el segundo sugiere la sustitución con heparina. El objetivo de este trabajo es revisar la literatura que tratar este tema con el fin de obtener un protocolo ideal. Conclusiones. En caso de extracciones simples es suficiente usar anestesia con vasoconstrictor (en el caso de que no haya otras contraindicaciones), realizar suturas bien tensadas, aplicar coadyuvantes hemostáticos locales y ácido tranexámico tópico. Solo en casos de intervenciones más complejas, o con valores de INR mayores a 3,5, será necesario reducir la dosis del fármaco y consecuente sustitución con heparina de acuerdo a las instrucciones del hematólogo y del cardiólogo (AU)

Aim of the work. In patients treated with oral anticoagulants, even simple tooth extractions can produce large hemorrhages. There are two main therapeutic outlines suggested in literature in case of little oral surgery. The first one is based on the reduction of the therapeutic dose of the drug, and the second one on the substitution with heparin. The aim of this paper was to review the. Literature on the management of patients treated with anticoagulants in order to obtain univocal guidelines. Conclusion. In case of simple tooth extractions generally a vasoconstrictive anaesthetic (if there are no other contraindications), tight sutures, the application of hemostats and tronexamic acid are enough. Only in case of more complex surgery or of INR values higher than 3,5 it is necessory to reduce the anticoagulant dose or to change the therapy with heparin, if agreed by the hoemotologist and/ or the cardiologist (AU)

Fibrolipoma gigante de la mejilla: a propósito de un caso / Giant fibrolipoma of the cheek: report of a case

El fibrolipoma es una neoplasia de origen mesenquimal, rara en la cavidad oral, representando el 1% de todos los tumores benignos orales. Es una variante histológica del lipoma simple, que normalmente se manifiesta a nivel de la mucosa oral, suelo de la boca, lengua y labios. La etiología suele ser traumática cuando afecta localizaciones extraorales, mientras se considera idiopática al manifestarse a nivel bucal. En este artículo se presenta un caso raro de fibrolipoma de mejilla, y se discuten los aspectos diagnósticos, histo-patológicos y de tratamiento de acuerdo a la literatura (AU)

Lipomas are common soft tissue mesenchymal neoplasms, rare in the oral cavity, representing 1% of all benign oral tumors. Fibrolipoma is a histopathological variant of the classic lipoma which normally affects buccal mucosa, floor of the mouth, tongue and lips. In this article is presented a rare case of fibrolipoma of the cheek and are discussed all the aspects of diagnosis, histology and surgical treatment, according to literature data (AU)

El neutrófilo y su importancia en la enfermedad periodontal / The neutrophil and the relationship with the periodontal disease

El presente artículo es una revisión bibliográfica del papel que cumple el neutrófilo dentro del sistema inmunológico y de la relación que existe entre esta célula y la enfermedad periodontal. Las defensas del organismo están representadas por el sistema inmunológico, encargado de evitar el ingreso de cualquier agente extraño o de destruirle en caso de haber traspasado previamente las barreras biológicas. El neutrófilo es una de las células más importantes de este sistema, siendo la primera defensa contra infecciones bacterianas y fúngicas. Deficiencias en su número y/o función pueden provocar el desarrollo de enfermedad periodontal a consecuencia de una disminuida respuesta inmune del huésped. Por otro lado, una mayor actividad por parte de esta célula o, más concretamente, una excesiva liberación de su contenido al espacio extracelular, puede producir daño tisular, una de las consecuencias de la evolución de la Enfermedad Periodontal (AU)

This paper reviews the role of the neutrophil in the immune system and the relationship between this cell and periodontal disease. The immune system represents the individual's defences avoiding the entry of foreign agents into the organism, or otherwise trying to destroy them if the biological barriers are trespassed. Neutrophil is one of the most important cells of the immune system, and represents the first defence line against bacterial and fungal infections. Deficiency in its number and/or function can elicit the development of periodontal disease due to a decreased immune response. On the other hand, a hyperactivity or an excessive release of the cell's content into the extracellular compartment, can produce tissue damage, which is the main consequence of periodontal disease (AU)