Utilización de injertos óseos autólogos y biomateriales en pacientes con atrofia alveolar. Matanzas / Use of autologous bone grafts and biomaterials in patients with alveolar atrophy.Matanzas

RESUMEN Introducción: los injertos óseos constituyen una de las técnicas más utilizadas en la cirugía reconstructiva implantológicas, son muy utilizadas para el reemplazo del hueso perdido por traumatismos, procesos patológicos congénitos o adquiridos y atrofia, son los injertos óseos autógenos o autólogos. Objetivo: caracterizar los pacientes con rebordes atróficos que necesitaron ser rehabilitados en implantología oral como alternativa de tratamiento en la consulta de Cirugía Máxilo Facial del Hospital Universitario "Faustino Pérez" y la Clínica "III Congreso del PCC", municipio Matanzas de septiembre del 2014 a julio de 2016. Material y Método: estudio prospectivo longitudinal. El universo fue de 20 pacientes mayores de 18 años de ambos sexos, que presentaron el diagnóstico de edentulismo parcial y atrofia alveolar. Se determinó por el interrogatorio, el examen clínico y los medios diagnósticos los síntomas y signos que caracterizaron esta entidad. Resultados: los traumatismos alveolares fue la causa que predominó en la pérdida dentaria, en el sexo masculino y en las edades de 18 a 37 años. La zona de mayor afectación fue la región anterior del maxilar superior y predominó la perdida de hueso en altura y en anchura y un gran número de injertos conservaron la cresta alveolar. Conclusiones: el uso de biomateriales en el tratamiento de pacientes con atrofia alveolar junto al injerto óseo fue satisfactorio en pacientes que necesitaron una base de sostén sobre la cual se colocaron los implantes dentales osteointegrados (AU).

SUMMARY Introduction: autogenous and autologous bone grafts are the elective material for replacing bones lost by trauma, congenital or acquired pathologic processes and atrophy. Objective: to characterize patients with atrophic rims needing rehabilitation in oral grafting as an alternative treatment in the Maxilla-Facial Surgery consultation of the University Hospital "Faustino Perez" and the Clinic "III Congreso del PCC", municipality of Matanzas, from September 2014 to July 2016. Materials and Methods: longitudinal prospective study. The universe was 20 patients aged 18 years and older, males and females, who presented the diagnosis of partial lack of teeth and alveolar atrophy. The symptoms and signs characterizing this entity were stated by questioning, physical examination and diagnostic means. Results: alveolar traumas were the predominant cause of dental lost in male patients aged 18-37 years. The most affected zone was the anterior region of the upper maxilla; bone lost in height and width predominated, and a great number of grafts conserved the alveolar crest. Conclusions: the use of biomaterials in the treatment of patients with alveolar atrophy together with bone graft was satisfactory in patients who needed a base support on which to put dental grafts (AU).

Effects of alveolar bone displacement with segmental osteotomy: micro-CT and histomorphometric analysis in rats.

The purpose of this study was to evaluate the effects of segmental osteotomy on the blood vessels and osteoclasts in rats using micro-computed tomography (micro-CT) and histomorphometric analysis. After segmental osteotomy was performed around the maxillary first molars of 36 male Sprague-Dawley rats (n = 72), the samples were divided into a control group (no displacement), 0.5 D group (0.5 mm buccal displacement) and 1.0 D group (1.0 mm buccal displacement) (n = 24/group). At 1, 2, 4 and 8 weeks after surgery, changes in the blood vessel volume were investigated using micro-CT with perfusion of radiopaque silicone rubber. Tartrate-resistant acid phosphatase (TRAP) staining was used for histomorphometric analysis. Two-way repeated measures analysis of variance (rmANOVA) was performed to compare the volume of blood vessels and number of TRAP-positive osteoclasts among the groups. Regarding blood vessel volume, the displacement groups had no significant effects, while the time points had significant effects (p = 0.014). The blood vessel volume at 1 week was significantly smaller than that at 2, 4, and 8 weeks (p = 0.004, p = 0.026, and p = 0.005, respectively). Regarding TRAP cell count, the displacement groups had no significant effects, while the time points had significant effects (p < 0.001). The number of TRAP-positive osteoclasts at 8 weeks was significantly smaller than that at 1, 2, and 4 weeks (p < 0.001, p < 0.001, and p = 0.002, respectively), and the count at 4 weeks was smaller than that at 1 week (p = 0.011). Therefore, a regional osteoclast-related acceleratory phenomenon was maintained until 4 weeks after surgery.

Effects of alveolar bone displacement with segmental osteotomy: micro-CT and histomorphometric analysis in rats

Abstract The purpose of this study was to evaluate the effects of segmental osteotomy on the blood vessels and osteoclasts in rats using micro-computed tomography (micro-CT) and histomorphometric analysis. After segmental osteotomy was performed around the maxillary first molars of 36 male Sprague-Dawley rats (n = 72), the samples were divided into a control group (no displacement), 0.5 D group (0.5 mm buccal displacement) and 1.0 D group (1.0 mm buccal displacement) (n = 24/group). At 1, 2, 4 and 8 weeks after surgery, changes in the blood vessel volume were investigated using micro-CT with perfusion of radiopaque silicone rubber. Tartrate-resistant acid phosphatase (TRAP) staining was used for histomorphometric analysis. Two-way repeated measures analysis of variance (rmANOVA) was performed to compare the volume of blood vessels and number of TRAP-positive osteoclasts among the groups. Regarding blood vessel volume, the displacement groups had no significant effects, while the time points had significant effects (p = 0.014). The blood vessel volume at 1 week was significantly smaller than that at 2, 4, and 8 weeks (p = 0.004, p = 0.026, and p = 0.005, respectively). Regarding TRAP cell count, the displacement groups had no significant effects, while the time points had significant effects (p < 0.001). The number of TRAP-positive osteoclasts at 8 weeks was significantly smaller than that at 1, 2, and 4 weeks (p < 0.001, p < 0.001, and p = 0.002, respectively), and the count at 4 weeks was smaller than that at 1 week (p = 0.011). Therefore, a regional osteoclast-related acceleratory phenomenon was maintained until 4 weeks after surgery.

Periodontal dressing after surgical crown lengthening: a randomized clinical trial.

OBJECTIVE: The aim of the present study was to evaluate the effect of periodontal dressing on post-operative pain and swelling after surgical crown lengthening. MATERIALS AND METHODS: A blind, randomized, clinical trial was carried out with 36 patients. Following surgical crown lengthening, the individuals were randomly allocated to the periodontal dressing group (PDG) and control group (CG, non-placement of periodontal dressing). Pain and discomfort were analyzed using a visual analog scale (VAS), verbal scale (VS) and the number of analgesics consumed in 7 days post-operatively. Post-operative infection, stability of the gingival margin and type of healing were also evaluated. RESULTS: The PDG had a significantly higher percentage of responses of 'strong pain' on the VS in the first day post-operatively (33.3% vs 5.3%, p = 0.03) and greater pain on the first and second days post-operatively based on the VAS. Moreover, a significant difference between groups was found regarding gingival swelling after 7 days. However, gingival recession was found in 57.8% of the sites in the CG and only 5.5% of sites in the PDG. No change in condition was found among individuals with conjunctive tissue/bone exposure in the CG in the immediate post-operative period and 80% of the patients in the PDG had healing by first intention after 7 days. CONCLUSION: The use of periodontal dressing seems to be preferable following surgical crown lengthening with connective tissue/bone exposure. However, adequate post-operative analgesic strategies should be employed due to the possibility of intense pain in the first 24 hours.

Open-flap versus flapless esthetic crown lengthening: 12-month clinical outcomes of a randomized controlled clinical trial.

BACKGROUND: Excessive gingival display (EGD) has a negative impact on a pleasant smile. Minimally invasive therapeutic modalities have become the standard treatment in many dentistry fields. Therefore, the aim of this study is to compare the clinical outcomes of open-flap (OF) and minimally invasive flapless (FL) esthetic crown lengthening (ECL) for the treatment of EGD. METHODS: A split-mouth randomized controlled trial was conducted in 28 patients presenting with EGD. Contralateral quadrants received ECL using OF or FL techniques. Clinical parameters were evaluated at baseline and 3, 6, and 12 months post-surgery. The local levels of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) were assessed by enzyme-linked immunosorbent assay at baseline and 3 months. Patients' perceptions regarding morbidity and esthetic appearance were also evaluated. Periodontal tissue dimensions were obtained by computed tomography at baseline and correlated with the changes in the gingival margin (GM). RESULTS: Patients reported low morbidity and high satisfaction with esthetic appearance for both procedures (P >0.05). RANKL and OPG concentrations were increased in the OF group at 3 months (P <0.05). Probing depths were reduced for both groups at all time points, compared with baseline (P <0.05). There were no differences between groups for GM reduction at any time point (P >0.05). CONCLUSIONS: FL and OF surgeries produced stable and similar clinical results up to 12 months. FL ECL may be a predictable alternative approach for the treatment of EGD.

Steroidal and non-steroidal cyclooxygenase-2 inhibitor anti-inflammatory drugs as pre-emptive medication in patients undergoing periodontal surgery.

The aim of the present study was to compare the pre-emptive use of a cyclooxygenase-2 (COX-2) inhibitor with a well established steroidal anti-inflammatory drug for pain and edema relief following periodontal surgery for crown lengthening. Thirty patients requiring periodontal surgery were randomly assigned to receive one of the following medications: selective COX-2 inhibitor or steroidal anti-inflammatory drug, 60 min before the surgical procedure. To examine patient anxiety, a Corah's dental anxiety scale was applied before surgery. Using a visual analog scale, the extent of pain/discomfort during the trans-operative period and immediately after the surgery was measured. Additionally, intensity of pain/discomfort and edema were examined 4, 8, 12 and 24 h postoperatively. With regard to anxiety, no statistical differences between the groups were observed (p>0.05). With respect to the extent of pain/discomfort during the trans-operative, immediate and late postoperative period, data demonstrated no significant differences (p>0.05) between the COX-2 inhibitor and steroidal groups. With regard to edema, intragroup analysis did not reveal any statistically significant difference (p>0.05) during the 24 h following surgery in either group. In conclusion, both anti-inflammatory drugs presented a similar potential for pain and edema relief following periodontal surgery.

Steroidal and non-steroidal cyclooxygenase-2 inhibitor anti-inflammatory drugs as pre-emptive medication in patients undergoing periodontal surgery

The aim of the present study was to compare the pre-emptive use of a cyclooxygenase-2 (COX-2) inhibitor with a well established steroidal anti-inflammatory drug for pain and edema relief following periodontal surgery for crown lengthening. Thirty patients requiring periodontal surgery were randomly assigned to receive one of the following medications: selective COX-2 inhibitor or steroidal anti-inflammatory drug, 60 min before the surgical procedure. To examine patient anxiety, a Corah's dental anxiety scale was applied before surgery. Using a visual analog scale, the extent of pain/discomfort during the trans-operative period and immediately after the surgery was measured. Additionally, intensity of pain/discomfort and edema were examined 4, 8, 12 and 24 h postoperatively. With regard to anxiety, no statistical differences between the groups were observed (p>0.05). With respect to the extent of pain/discomfort during the trans-operative, immediate and late postoperative period, data demonstrated no significant differences (p>0.05) between the COX-2 inhibitor and steroidal groups. With regard to edema, intragroup analysis did not reveal any statistically significant difference (p>0.05) during the 24 h following surgery in either group. In conclusion, both anti-inflammatory drugs presented a similar potential for pain and edema relief following periodontal surgery.

O objetivo do presente estudo foi comparar a utilização pré-emptiva de medicamento inibidor da COX-2 (cicloxigenase-2) com uma droga antinflamatória esteroidal amplamente utilizada, para o controle da dor e edema após cirurgia periodontal para aumento de coroa. Trinta pacientes que necessitavam de cirurgia periodontal foram aleatoriamente designados a receber uma das seguintes medicações: inibidor seletivo da COX-2 ou a droga antinflamatória esteroidal, 60 min antes do procedimento cirúrgico. Para avaliar a ansiedade do paciente, a escala de ansiedade ao tratamento dental de Corah foi aplicada antes da cirurgia. Com a utilização de escala analógica visual a extensão de dor/desconforto durante o período trans-cirúrgico e imediatamente após a cirurgia foi mensurada. Adicionalmente, a intensidade de dor/desconforto e edema foram avaliados no periodo pós-operatório tardio 4, 8, 12 e 24 h após o procedimento cirúrgico. Com relação à ansiedade, não foi observada diferença estatística entre os grupos (p>0,05). Com relação à extensão de dor/desconforto durante os períodos trans-cirúrgico e pós operatório imediato e tardio, os dados não demonstraram diferenças entre o grupo que recebeu o inibidor seletivo da COX-2 e o aintinflamatório esteroidal (p>0,05). A avaliação do edema, intragrupo, não revelou diferença estatística durante as primeiras 24 h em nenhum dos grupos estudados (p>0,05). Em conclusão, ambas as drogas antiinflamatórias utilizadas apresentaram um potencial similar no controle da dor e edema após cirurgia periodontal.

Bone healing after bur and Er:YAG laser ostectomies.

PURPOSE: Ostectomies, performed by different methods, are often necessary in oral and maxillofacial surgery. Rotatory and reciprocating devices are most frequently used but have disadvantages, such as noise, vibration, and the potential for inducing thermal damage. Laser systems are interesting alternatives to these procedures. We analyzed bone healing in a rat model after mandibular ostectomy with a surgical bur or noncontact erbium:yttrium-aluminum-garnet laser using different energy levels. MATERIALS AND METHODS: Four groups of 5 rats each underwent ostectomy of the bone cortical of the mandibular body, with irrigation, using a surgical bur or erbium:yttrium-aluminum-garnet laser with different energy parameters. A metal plate was used for morphologic standardization of the cavities. The samples collected after 7, 14, 45, 60, and 90 days were analyzed by optical microscopy. RESULTS: The ostectomies performed with surgical burs resulted in bone healing from the cortical endosteum and remaining trabecular bone. The cortical endosteum was repaired after 45 days, followed by bone remodeling. After laser irradiation, healing involved bone neoformation from the external cortical surface and endosteum. Surface regions with thermal damage were observed after laser treatment in the 3 conditions used up to day 60, followed by bone remodeling. CONCLUSIONS: Laser ostectomies resulted in a thin layer of thermal damage. Bone healing was faster when surgical burs were used, with similar results reached after 90 days.

Effects of surgical removal of mandibular third molar on the periodontium of the second molar.

OBJECTIVE: The effects on periodontal tissues of adjacent second molars after semi-impacted mandibular third molar surgery were evaluated. The influence of flap design was studied. METHODS: Twenty volunteers randomly underwent the three-cornered flap technique (group A) or the distal wedge flap technique (group B). The periodontal probing depth was measured by using a 'Williams'-type probe just prior to surgery and three months post-operatively. Six sites, mesio-buccal, buccal, disto-buccal, disto-lingual, lingual and mesio-lingual, around the second molar were selected for measurement. Kruskal-Wallis test and Dunn test (post hoc) were used. Significance level was set at 5%. RESULTS: There were no complications (oedema, alveolitis, etc.) in any of the patients of the study. The results showed that both methods caused shallow pocket depth (P > 0.05) and there were no statistically significant differences between the flap techniques (P > 0.05). Flap design was not an important factor affecting the periodontal status of the second molar. CONCLUSION: The decision to use any of the various flap designs for access to mandibular third molars should be based on operator preference rather than on the assumption that periodontal health of the adjacent second molar will be improved.

Efeitos da corticotomia alveolar na estrutura óssea e na movimentação ortodôntica / Effect of localized alveolar corticotomies on the alveolar bone structure and orthodontic tooth movement

No presente estudo investigou-se os efeitos de corticotomias alveolares localizadas (CAL) na estrutura do osso alveolar e como a movimentação ortodôntica foi afetada pelo trauma cirúrgico resultante da CAL. No primeiro experimento, dezesseis cães sem raça definida (SRD) adultos e machos foram, aleatoriamente, divididos em quatro grupos. Os animais do grupo controle foram sacrificados antes da cirurgia e os cães dos grupos experimentais G7, G14 e G28, respectivamente aos, 7, 14 e 28 dias após a realização de CAL. Corticotomias alveolares localizadas foram realizadas nas corticais vestibular e lingual, circunscrevendo o terceiro pré-molar inferior direito, com o lado esquerdo servindo como controle intra-animal. A análise da densidade óssea revelou diminuição localizada da densidade do osso alveolar, com redução máxima acontecendo uma semana pós-CAL e recuperação progressiva, porém parcial, dos valores de densidade óssea inicial, duas e quatro semanas, após a realização das cirurgias. Os estudos histomorfométricos e de microscopia eletrônica de varredura mostraram que o osso trabecular, adjacente às áreas traumatizadas pelas CAL, sofreu mudanças fisiológicas e estruturais consistentes com o desenvolvimento de osteopenia (aumento dos espaços trabeculares e diminuição da densidade óssea). No segundo experimento, outros cinco cães SRD tiveram os arcos dentários submetidos, à movimentação ortodôntica, sendo o quadrante inferior direito, imediatamente após a realização de CAL e o esquerdo serviu como controle. Após dez semanas de aplicação de forças ortodônticas, recíprocas e constantes, nos segundos e quartos pré-molares inferiores, maior movimentação dentária e menor perda de ancoragem, foram registradas no lado submetido à CAL. Os resultados demonstraram que a realização de corticotomias alveolares localizadas afetou a estrutura do osso trabecular adjacente, reduzindo a densidade óssea e potencializando a movimentação ortodôntica. Finalmente...

Histologic evaluation of the effect of nicotine administration on bone regeneration: a study in dogs

O objetivo do presente estudo foi avaliar histometricamente a influência da nicotina sobre a regeneração óssea de defeitos criados cirurgicamente em rebordos alveolares edêntulos de cães. Defeitos ósseos foram criados cirurgicamente em um dos lados da mandíbula de dezesseis cães e foram deixados para que curassem espontanea-mente. Os animais foram aleatoriamente designados para um dos seguintes grupos: Grupo 1 - controle (n = 8) e Grupo 2 - administração subcutânea de nicotina (2 mg/kg) duas vezes ao dia durante 4 meses (n = 8). Os animais foram sacrificados, e secções semi-seriadas descalcificadas, obtidas. Os parâmetros histométricos avaliados foram altura, largura, área e densidade do tecido ósseo neoformado. A análise intergrupos (Mann-Whitney "rank sum test") demonstrou que a administração de nicotina não influenciou altura, largura e área de tecido ósseo neoformado (p > 0,05). Entretanto, a administração de nicotina influenciou significativamente a densidade do tecido ósseo neoformado (p < 0,001). Dentro dos limites do presente estudo, pode-se concluir que a nicotina pode afetar, mas não impedir a regeneração de defeitos ósseos criados cirurgicamente em mandíbulas edêntulas de cães.

Transurgical restoration in the absence of attached gingiva. A case report.

A 45-year-old woman needing a Class V restoration in a mandibular molar without attached gingiva is presented. In an interdisciplinary intervention, transurgical restoration was accomplished, including flap surgery with a slight ostectomy and restoration with a bonding system and a resin composite. A 1-year clinical evaluation showed satisfactory marginal adaptation and restoration contour associated to gingival tissue health.

Histologic evaluation of the effect of nicotine administration on bone regeneration. A study in dogs.

The objective of this study was to investigate the histometric impact of nicotine on bone regeneration of surgically created alveolar ridge defects in dogs. Sixteen mongrel dogs were used. One defect was surgically created unilaterally in the mandible, and left to heal spontaneously. The animals were randomly assigned to one of the following groups: Group 1--control (n = 8) and Group 2--subcutaneous nicotine administration (2 mg/kg) twice a day (n = 8). After 4 months, the animals were sacrificed and the specimens routinely processed for semi-serial decalcified sections. Bone height (BH), bone width (BW), bone density (BD), and bone area (BA) of the newly-formed bone were evaluated. Intergroup analysis (Mann-Whitney rank sum test) showed that regardless of the presence of nicotine, no significant differences were observed regarding bone width (BW), bone area (BA) and bone height (BH) (p > 0.05). On the other hand, it was demonstrated that nicotine administration significantly influenced the proportion of mineralized tissue within the limits of the newly-formed bone (BD) (p < 0.001). Within the limits of the present study, it can be concluded that nicotine might affect but not prevent bone healing in defects left to heal spontaneously.

Surface characteristics of implants influence their bone integration after simultaneous placement of implant and GBR membrane.

The purpose of this study was to evaluate the influence of titanium surface characteristics on bone integration of implants, and to describe the pattern of peri-implant tissue healing after simultaneous implant placement and guided bone regeneration. In four healthy mongrel dogs mandibular premolars were extracted. Two weeks following full mouth prophylaxis and 4 months after extractions, simultaneous membrane and implant surgeries were performed. Efforts were made to produce bony defects with dimensions of 7 x 7 x 7 mm. Into these, 24 standard ITI implants (diameter = 4.1 mm; length = 8 mm) with either a titanium plasma-sprayed (TPS) or a machined surface (MS) were placed. Although implants were inserted 4 mm into cancellous bone, difficulties in achieving optimal primary stability were encountered. All dogs were maintained on a soft diet. Chlorhexidine rinses were performed three times a week. Full mouth prophylaxis was performed every 2 weeks. In the case of membrane exposure, the membranes were removed prematurely (4-6 or 14-15 weeks after surgery). Two dogs were sacrificed at 16 weeks and two at 24 weeks after surgery. Nondecalcified histologic sections were processed and histometric analyses were carried out. When membranes were removed after 4-6 weeks, a vertical bone growth (VB) of 45-61% of the original defect was noted. After membrane removal at 14-15 weeks, similar VB was observed. However, if membranes were left in situ for 24 weeks, VB was between 79% and 96%. In this group of sites, the VB was 66% at 16 weeks and 86% at 24 weeks. Osseointegration in the regenerated bone area ranged from 12% to 32% for the TPS and from 0.0% to 3.6% for the MS implants at 16 and 24 weeks combined. Osseointegration in the pristine host bone area ranged from 16% to 35% for the TPS and from 0.0% to 11% for the MS sites at 16 and 24 weeks. In conclusion, the fraction of implant-bone integration was much higher in the pristine bone compared to that in the regenerated bone. TPS surfaces positively influenced the fraction of osseointegration in comparison to MS surfaces for both regenerated and pristine bone. Furthermore, early membrane removal negatively affected the fraction of bone defect fill.

Reattachment of an autogenous tooth fragment in a fracture with biologic width violation: a case report.

An 11-year-old patient that fractured her maxillary left central incisor is presented. The fracture involved two thirds of the crown, compromising the pulp, and extended subgingivally on the palatal aspect, invading the biologic width. The procedure used to repair the fracture included flap surgery with a slight ostectomy and endodontic treatment. The reattachment of the tooth fragment and the restoration were performed with a bonding system and a resin composite. Examination 6 months after treatment revealed periodontal health, good esthetics, and normal function.

Preprosthetic periodontal surgery in the interproximal area with modification of the COL area: anatomic and histologic study in dogs.

BACKGROUND: Due to its concave morphology, a COL creates difficulties for proper oral hygiene. When this characteristic is accentuated by tooth position or caries and when restorations are necessary, they should be corrected by preprosthetic surgery. However, there are no data proving the efficacy of the procedures. The purpose of this study was to evaluate tissue response to preprosthetic surgery to modify COL morphology. METHODS: Five mongrel dogs received apically positioned flaps, osteotomy/plasty, and RAI (restorative alveolar interface technique) on the maxillary right third bicuspid and first molar; on the same teeth on the left side, a large tissue excision similar to gingivectomy and RAI were performed. Histologic specimens stained with hematoxylin and eosin and Mallory were evaluated at hour 0 and 1, 2, 3, and 4 weeks under light microscopy. RESULTS: At hour 0, hemorrhage in the remaining interproximal tissue on the left side, and denuded bone modified by the osteotomy on the right side, were observed. At 1 week, both sides showed the presence of granulation tissue and the beginning of reepithelialization and fiber formation. At 2 weeks, the papillae were rebuilt and epithelialized, with fewer inflammatory cells and dilated blood vessels, with a convex morphology. At 3 weeks, the papillae were convex and saddle shaped, with thicker epithelium and denser connective tissue. The general aspect was similar to attached gingiva. However, on the right side, the total extension of the interproximal tissues was longer and had a less accentuated convex curvature. At 4 weeks, the tissues were more mature, but the morphologic and histological findings were similar to 3 weeks. CONCLUSION: Both techniques modified the COL morphology, suggesting that the RAI technique was effective; but the apically positioned flap with osteotomy and RAI created a more extensive convex surface and more interproximal space for the prosthesis. It is recommended that this technique be considered for use in humans.

Ridge augmentation following implantation of recombinant human bone morphogenetic protein-2 in the dog.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) carrier induces bone for reconstruction of skeletal defects. The rhBMP-2/ACS implant is prepared by administering a rhBMP-2 solution to dry ACS. Once prepared, rhBMP-2/ACS forms a moldable, cohesive, and adhesive implant. However, rhBMP-2/ACS does not have sufficient structural strength to withstand soft tissue compression at specific anatomic sites. To more fully understand the mechanisms that affect bone induction by rhBMP-2/ACS in the presence of soft tissue compression, it would be useful to have a preclinical model that appropriately simulates such circumstances in patients. This pilot study evaluated one such potential model. METHODS: Bilateral, Class III alveolar defects were surgically produced in 4 adult mongrel dogs following extraction of the mandibular fourth premolars and reduction of the alveolar ridge. After an 8-week healing interval, mucoperiosteal flaps were elevated and rhBMP-2/ACS or rhBMP-2/ACS combined with hydroxyapatite (HA) was implanted into contralateral defects. The animals were euthanized at 12 weeks post-augmentation and block biopsies processed for histologic evaluation. RESULTS: Limited augmentation followed implantation of rhBMP-2/ACS (0.7 +/- 0.6 mm). In contrast, sites receiving rhBMP-2/ACS/HA exhibited clinically relevant ridge augmentation (5.5 +/- 1.6 mm). Defects implanted with rhBMP-2/ACS exhibited dense trabeculation within the corpus of the reduced alveolar process. The cortices appeared intact without evidence of expansion into the defect area. Three defects receiving rhBMP-2/ACS/HA exhibited sparse bone trabeculae amidst HA particles, fibrovascular tissue, and marrow. Commonly, the HA particles were encapsulated by fibrous tissue. Some particles were observed in contact with bone. CONCLUSIONS: The results suggests that rhBMP-2/ACS has limited effect alone in this augmentation model of Class III alveolar ridge defects. Inclusion of HA into the rhBMP-2 construct results in clinically relevant augmentation, however, the quality of bone is compromised.

Peripheral ameloblastoma.

A case of peripheral ameloblastoma in a 57-years-old woman is presented, along with a discussion of the clinical and histological characteristics of the lesion. After clinical and radiographic examinations, and with a differential diagnosis of pyogenic granuloma, an excisional biopsy was performed and the material collected was sent for histological examination. On the basis of the histopathological diagnosis, a second operation was performed with a wide safety margin, including bone tissue, which did not show any involvement with the odontogenic neoplasm.