Conventional extraction vs. enucleation in anterior maxillary sites: a pilot study in humans

Abstract: Background: Surgical extraction of ankylosed roots may cause severe defects of the alveolar crest. The aim of the present study was to determine the effects of flapless enucleation on the frequency of osteotomy and the maintenance of the alveolar crest width. Method: Ten patients (3 m, 7 f) requiring extractions in the anterior maxil- lary zone were included and randomly treated with conventional extraction and flapless microsurgical enucleation; osteotomy served as rescue technique in both groups. Socket preservation was performed using in situ hardening TCP bone substitute. Results: In the extraction group, 4/10 patients required osteotomy, in the enucleation group 0/10 (P<0.05, chi-square test). The alveolar widths 3 mm below the gingiva before surgery, at 3 and 6 months were 11.50, 8.98, and 9.50 mm in the extraction group and 12.25, 11.35, and 11.25 mm in the enucleation group, re- spectively. Two of 10 control sites and 0 of 10 test sites required augmentation for implant placement. Conclusion: Flapless enucleation combined with socket preservation appears to provide adequate maintenance of alveolar structures for implant placement and may be an alternative for surgical extraction in ankylosed anterior maxillary sites.Fil: Decco, Oscar Alfredo. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; ArgentinaFil: Zuchuat, Jésica Itatí. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Entre Ríos. Universidad Nacional de Entre Ríos. Centro de Investigaciones y Transferencia de Entre Ríos; ArgentinaFil: Cura, Andrea Cecilia. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Entre Ríos. Universidad Nacional de Entre Ríos. Centro de Investigaciones y Transferencia de Entre Ríos; ArgentinaFil: Decco, Jorgelina Andrea. Universidad Nacional de Rosario. Facultad de Odontologia; ArgentinaFil: Engelke, Wilfried. Universität Göttingen; Alemani

Image-based analysis of trabecular bone in osteoporotic rabbits: Correlation of morphological features and bone mineral density profile

Objective: To analyse a set of morphological features from digital radiographs (RX) and bone mineral density (BMD) values estimated from quantitative computerized tomography scans (QCT scans) of the knee joint of an osteoporotic rabbits, and to determine the relationship and correlation of these variables to be considered as an alternative diagnosis method. Methods: The knee joint of rabbits (N = 9 ovariectomized and injected with of methylprednisolone sodium succinate (OVX + MPSS) and 3 sham operated healthy controls) were subjected to radiographic examination before the beginning of the study and after 6 weeks; after sacrifice, they were immediately scanned with a 64-channel CT. A set of morphological features was extracted from RX images and then subjected to Principal Component Analysis (PCA); BMD-values were calculated at different depths from the articular surface of the femur and the tibia. The selected morphological variables and the BMD values were correlated in order to determine useful information in medical diagnostics. Results: Ten morphological variables explained 80.39% of the total variability, but only some of them demonstrated significant differences between baseline and OVX + SSMP states and between OVX + SSMP and control. Spearman analysis showed higher positive and negative correlation of these parameters among them (r = 0.67, 0.81, 0.83 and 1); and a moderate correlation with the BMD values (r = 0.50, 0.52, 0.52 and 0.55) during the progression of osteoporosis (OP). Conclusion: The Spearman's rank test supported the overall significant correlation between both, the morphological features and BMD values, making them as a reliable alternative option to the diagnosis of osteoporosis.Fil: Zuchuat, Jésica Itatí. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Manzano, Adriana Silvina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Decco, Oscar Alfredo. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; Argentin

Minimally Invasive Technique For Transalveolar Sinus Floor Elevation with A Diamond Burr Used in Skull Base Surgery: A Case Series

When alveolar ridges lack the appropriate bone volume for implant placement, additional surgicalprocedures are necessary. In the posterior maxilla, the pneumatization of the maxillary sinus reduces theresidual crestal height, and to perform implant placement, several sinus floor elevation techniques have beendeveloped. These techniques involve specific instruments that require some experience, especially whenperforming sinus membrane lifting because of its importance for surgery success. A minimally invasivetransalveolar sinus floor elevation technique is presented, in which a diamond burr used in cranial base surgeryis employed. Surgery was performed on 10 patients. Panoramic radiographs and computerized tomography(CT) scans were taken before surgery and 1 month and 2 years after surgery, and they were used to measurebone height. The achieved augmentation heights were between 2.18 and 5.93 mm. All of the surgical procedureswere conducted without complications. No Schneiderian membrane was perforated, and a verticalaugmentation for allowing implant placement was achieved. It represent a good technique for minimallyinvasive sinus floor elevation.Fil: Decco, Oscar Alfredo. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; ArgentinaFil: Zuchuat, Jésica Itatí. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; ArgentinaFil: Maldonado, Ysai. Sanatorio Adventista del Plata; Argentin

Improvement of Cr-Co-Mo membrane surface used as barrier for bone regeneration through UV photofunctionalization: An in vitro study

Although there are several studies of the ultraviolet (UV) light-mediated photofunctionalization of titanium for use as implant material, the underlying mechanism is not fully understood. However, the results of in vitro and in vivo studies are very encouraging. The use of UV photofunctionalization as a surface treatment on other implant materials, as the Cr-Co-Mo alloy, has not been explored in depth. Using sandblasted Cr-Co-Mo discs, the surface photofunctionalization was studied for ultraviolet A (UVA, 365 nm) and ultraviolet C (UVC, 254 nm), and the surfaces were evaluated for their ability to sustain hydroxyapatite crystal growth through incubation in simulated body fluid for a seven-day period. The variation of the pre- and post-irradiation contact angle and surface composition was determined through the quantification of the weight percentage of Ca and P crystals by the EDAX ZAF method (EDS). Statistically significant differences (p < 0.05) were found for samples irradiated with UVA over 48 h, corresponding with hydrophilic surfaces, and the same result was found for samples exposed to 3 h of UVC. Superhydrophilic surfaces were found in samples irradiated for 12, 24 and 48 h with UVC. The decrease in the carbon content is related with the increase in the surface content of Ca and P, and vice versa over the Cr-Co-Mo surfaces.Fil: Decco, Oscar Alfredo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Zuchuat, Jésica Itatí. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Farkas, Nicolás. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentin

In vivo effect of UV-photofunctionalization of CoCrMo in processes of guided bone regeneration and tissue engineering

Photofunctionalization of implant materials with ultraviolet (UV) radiation have been subject of study in the last two decades, and previous research on CoCrMo discs have showed good results in terms of bioactivity and the findings of apatite-like crystals in vitro. In the current study, CoCrMo domes were photofunctionalized with UV radiation of 254 nm on their internal faces during 24 hr; they were implanted in rabbit tibia and remained for 3, 4, and 6 weeks. The potential to induce bone formation beneath the dome-shaped membranes was evaluated through morphometric, histologic, and density measurements; and the results were compared with those obtained under control untreated domes. Higher density values were observed for irradiated domes at 3 weeks, whereas higher volumes were obtained under photofunctionalized domes for longer periods (4 and 6 weeks). Histologically, woven bone was formed by endochondral ossification in all cases; differences in the architecture and size of the trabeculae and in the number of osteoblasts were noted between irradiated and non-irradiated samples. The UV radiation of 254 nm generated a larger bone volume fraction compared to that found in the absence of UVC radiation and induced an increase of density in the early stages of healing, leading to a better initial bone quality and improved osseointegration.Fil: Zuchuat, Jésica Itatí. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Maldonado, Ysaí. Sanatorio Adventista Del Plata; ArgentinaFil: Botteri, Julián. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Decco, Oscar Alfredo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentin

Sandblasted, acid etched and UV irradiated titanium surface for dental implants: In vitro and in vivo analysis

In the implant dentistry field, rehabilitation through osseointegrated implants have been a huge advance, leading to excellent outcomes. Biomaterial integration to bone tissue determines the implant clinical success and the recovery of lost functionality, depending on clinical and engineering factors and patient whole health. Because of this, it is important the development of new strategies to achieve higher success rates and to decrease the healing period of osseointegrated implants. The present study addresses the UV irradiation effect on superficial characteristics of sandblasted and acid etched titanium discs. Furthermore, the irradiation protocol with the best outcomes was selected and applied to titanium implants placed in vivo in order to study the influence of the UV irradiation over the surrounding tissue. The results showed that UVC, but not UVA, enhanced surface hydrophilicity significantly. After 24 h of exposure to UVC, a superhydrophilic surface was obtained, with higher protein adsorption capability. New bone formation occurred for all the implants considered, with no detriment of surrounding tissue density and removal torque for UVC irradiated group. Further studies are needed to assess whether this improved surface promotes the growth of bone tissue around the implant.Fil: Cura, Andrea Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: Zuchuat, Jésica Itatí. Universidad Nacional de Entre Ríos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tribbia, Liliana Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: Taravini, Irene Rita Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: Decco, Oscar Alfredo. Universidad Nacional de Entre Ríos; Argentin

Displacement of dental implants in trabecular bone under a static lateral load in fresh bovine bone

Aim: The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion torque was determined at intervals of 10, 20, and 30 Ncm. Implants were loaded horizontally with 10, 20, and 30 N for 2 seconds. An indicator strip was attached to the implant abutment to allow direct observation of implant movement relative to the bone surface. Horizontal displacement was assessed with an accuracy of measurement of 10 µm. Seven implants got lost by visible loosening. Degree of displacement was subject to evaluation with all others. Those implants showed a mean displacement of 59 µm for 10 N (n = 100), 173 µm for 20 N (n = 99), and 211 µm for 30 N (n = 93). The mean displacement of 15-mm implants (16, 37, 51 µm) was significantly lower compared with 8.5-mm implants (103, 311, 396 µm) corresponding to 10, 20, and 30 N as lateral loads. Conclusions: Displacement of screw implants in trabecular bone can be detected and visualized using commercially available endoscopes with a high magnification. A lateral load of 20 N indicates a mean displacement of over 100 µm and therefore results in a critical displacement.Fil: Engelke, Wilfried. Universität Göttingen; AlemaniaFil: Müller, Alois. Private practice: dentist and oral surgeon; AlemaniaFil: Decco, Oscar Alfredo. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; ArgentinaFil: Rau, María J.. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería; ArgentinaFil: Cura, Andrea Cecilia. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruscio, Mara L.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Knösel, Michael. Universität Göttingen; Alemani