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1.
J Stomatol Oral Maxillofac Surg ; 121(6): 665-671, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32045687

RESUMEN

PURPOSE: The purpose of this study was to evaluate long-term three-dimensional graft resorption following reconstruction of the severely atrophic maxilla with anterior iliac crest bone grafting. METHODS: Twenty-two patients (13 males), who underwent autogenous bone grafting and implant placement to their severely atrophic maxillary alveolar ridges were identified and included in the study. Pre- and postoperative cone-beam computed tomography (CBCT) scans of 40 recipient grafting sites were evaluated to calculate volumetric changes over time. CBCT scans were performed preoperatively (V0) and one week (V1), three months (V2), one year (V3), and three years (V4) following the augmentation operation. RESULTS: The average graft resorption from V1 to V2, V1 to V3, and V1 to V4 was 31.42%, 33.96%, and 37.96%, respectively. Initial graft volume reduction within the first three months was statistically higher compared to other postoperative periods (P<0.013). The rate of resorption reduced slightly from the third month of the surgery (V2) (P>0.013). There was no statistical difference between resorption volume and gender, type of prosthesis, the presence of vestibuloplasty, or patient age (P>0.05). CONCLUSION: The overall success rate of the iliac bone block grafts was found to be high. The volumetric resorption rates associated with the graft were favourable for the reconstruction of the maxilla and for permitting the placement of dental implants three months after augmentation. The highest graft resorption was found at the third postoperative month. Placement and loading of the implants reduced the resorption rate slightly over time.


Asunto(s)
Aumento de la Cresta Alveolar , Implantes Dentales , Trasplante Óseo , Humanos , Ilion/diagnóstico por imagen , Ilion/cirugía , Masculino , Maxilar/diagnóstico por imagen , Maxilar/cirugía
2.
J Craniofac Surg ; 30(4): 1078-1084, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30839463

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the effect of mineralized plasmatic matrix (MPM), comprising a combination of synthetic graft and platelet concentrates, on bone regeneration. METHODS: Critical size defects of 6-mm diameter were created on the tibias of 6 male sheep, with the animals subsequently assigned into 2 groups. Of the 5 bone defects generated per animal, 4 were randomly filled with MPM, beta-tricalcium phosphate graft (ß-TCP), platelet-rich fibrin (PRF) + ß-TCP, and autogenous graft. One defect was left empty as a control group. Animals were killed at 3 weeks (early healing group) and 6 weeks (late healing group). The specimens underwent histologic and histomorphometric analysis to evaluate new bone formation. RESULTS: In both healing periods, new bone formation from autogenous bone was observed significantly more often than from biomaterials or the empty defect. The degree of new bone formation for MPM was significantly higher than that of the control group at all healing periods. In addition, it was significantly higher in both healing periods than that of ß-TCP albeit only in the late healing period than that of the PRF + ß-TCP combination. In all biomaterial groups, residual graft ratios decreased from early to late healing periods. CONCLUSION: The results indicated that MPM, representing growth factors in a fibrin network, increases new bone formation in surgically created defects in sheep tibia as confirmed by histologic assessment.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Fosfatos de Calcio/farmacología , Fibrina Rica en Plaquetas/fisiología , Animales , Autoinjertos , Materiales Biocompatibles/farmacología , Regeneración Ósea/fisiología , Trasplante Óseo , Fosfatos de Calcio/uso terapéutico , Masculino , Modelos Animales , Distribución Aleatoria , Ovinos , Tibia/citología , Tibia/fisiología , Cicatrización de Heridas/efectos de los fármacos
3.
J Oral Maxillofac Surg ; 75(4): 709-722, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27998736

RESUMEN

PURPOSE: To evaluate the rate of graft resorption in autogenous iliac bone grafting (IBG) and guided bone regeneration (GBR) in patients with atrophic maxillae. MATERIALS AND METHODS: We performed a retrospective study involving patients requiring implant placement who underwent IBG or GBR. Volumetric changes of the graft sites were evaluated by imaging studies. The primary predictor and outcome variables were augmentation technique and rate of volumetric resorption, respectively. Secondary outcome variables included bone gain, success of grafting, insertion torque of implants, and requirement for vestibuloplasty. RESULTS: The sample comprised 39 patients (21 with GBR and 18 with IBG). One patient in the IBG group had temporary sensory disturbance at the donor site, and one patient in the GBR group had late exposure of the nonresorbable membrane. The average values of percent volume reduction in the GBR and IBG groups were 12.26% ± 2.35% and 35.94% ± 7.94%, respectively, after healing and 15.87% ± 1.99% and 41.62% ± 6.97%, respectively, at last follow-up. The IBG group exhibited a significantly higher reduction in bone volume than the GBR group at both time points (P = .001). The mean values of horizontal and vertical bone gain after healing in the IBG group were significantly higher than those in the GBR group (P = .006 and P = .001, respectively). The mean implant torque during implant placement in the GBR group was significantly higher than that in the IBG group (P = .024). There was no significant difference in the requirement for vestibuloplasty between the two groups (P > .05). CONCLUSIONS: Although both hard tissue augmentation approaches provide an adequate volume of bone graft for implant insertion, IBG results in greater graft resorption at maxillary augmented sites than GBR. Clinicians should consider the differences in the extent of graft resorption between the two methods while choosing the treatment approach.


Asunto(s)
Aumento de la Cresta Alveolar/métodos , Regeneración Ósea/fisiología , Resorción Ósea/patología , Trasplante Óseo/métodos , Regeneración Tisular Dirigida , Ilion/trasplante , Imagenología Tridimensional , Maxilar/diagnóstico por imagen , Maxilar/patología , Maxilar/cirugía , Adulto , Anciano , Colágeno/farmacología , Implantación Dental Endoósea , Femenino , Humanos , Masculino , Membranas Artificiales , Persona de Mediana Edad , Politetrafluoroetileno/farmacología , Estudios Retrospectivos , Resultado del Tratamiento
4.
Biomed Res Int ; 2016: 4987437, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27847815

RESUMEN

Purpose. Bone atrophy after tooth loss may leave insufficient bone for implant placement. We compared volumetric changes after autogenous ramus block bone grafting (RBG) or guided bone regeneration (GBR) in horizontally deficient maxilla before implant placement. Materials and Methods. In this retrospective study, volumetric changes at RBG or GBR graft sites were evaluated using cone-beam computed tomography. The primary outcome variable was the volumetric resorption rate. Secondary outcomes were bone gain, graft success, and implant insertion torque. Results. Twenty-four patients (28 grafted sites) were included (GBR, 15; RBG, 13). One patient (RBG) suffered mucosal dehiscence at the recipient site 6 weeks after surgery, which healed spontaneously. Mean volume reduction in the GBR and RBG groups was 12.48 ± 2.67% and 7.20 ± 1.40%, respectively. GBR resulted in significantly more bone resorption than RBG (P < 0.001). Mean horizontal bone gain and width after healing were significantly greater in the GBR than in the RBG group (P = 0.002 and 0.005, resp.). Implant torque was similar between groups (P > 0.05). Conclusions. Both RBG and GBR hard-tissue augmentation techniques provide adequate bone graft volume and stability for implant insertion. However, GBR causes greater resorption at maxillary augmented sites than RBG, which clinicians should consider during treatment planning.


Asunto(s)
Aumento de la Cresta Alveolar/métodos , Regeneración Ósea , Resorción Ósea/patología , Trasplante Óseo , Regeneración Tisular Dirigida/métodos , Maxilar/cirugía , Procedimientos de Cirugía Plástica/métodos , Regeneración Ósea/efectos de los fármacos , Colágeno/farmacología , Femenino , Humanos , Modelos Lineales , Masculino , Maxilar/efectos de los fármacos , Persona de Mediana Edad , Resultado del Tratamiento
5.
Biomed Res Int ; 2016: 9695389, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27660765

RESUMEN

Purpose. To compare marginal bone loss between subgingivally placed short-collar implants with machined collars and those with machined and laser-microtextured collars. Materials and Methods. The investigators used a retrospective study design and included patients who needed missing posterior teeth replaced with implants. Short-collar implants with identical geometries were divided into two groups: an M group, machined collar; and an L group, machined and laser-microtextured collar. Implants were evaluated according to marginal bone loss, implant success, and probing depth (PD) at 3 years of follow-up. Results. Sixty-two patients received 103 implants (56 in the M group and 47 in the L group). The cumulative survival rate was 100%. All implants showed clinically acceptable marginal bone loss, although bone resorption was lower in the L group (0.49 mm) than in the M group (1.38 mm) at 3 years (p < 0.01). A significantly shallower PD was found for the implants in the L group during follow-up (p < 0.01). Conclusions. Our results suggest predictable outcomes with regard to bone loss for both groups; however, bone resorption was less in the L group than in the M group before and after loading. The laser-microtextured collar implant may provide a shallower PD than the machined collar implant.

6.
Biomed Res Int ; 2016: 4085079, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27517044

RESUMEN

Introduction. The bone volume of the posterior maxilla may not be appropriate for implant placement, due to factors such as pneumatized maxillary sinus. The purpose of this study was to evaluate the percentage of graft volume reduction following sinus floor elevation (SFE), with either slow resorbable bone substitute only or a composite of slow and fast resorbable bone substitutes, using cone beam computed tomography (CBCT). Materials and Methods. In this retrospective study, CBCT scans of SFE procedures were evaluated to determine the volume of grafted sinus with either deproteinized bovine bone (DBB) or a 2 : 1 mixture of biphasic calcium sulfate (CS) and DBB, as a composite. The volumetric changes of sinus augmentations were measured 2 weeks (V-I) and 6 months (V-II) after operation. Results. Thirty-three patients were included in this study. The average percentage volume reduction was 9.39 ± 3.01% and 17.65 ± 4.15% for DBB and composite grafts, respectively. A significant graft volume reduction was observed between V-I and V-II for both groups (p < 0.01). The DBB group exhibited significantly less volume reduction than the composite group (p < 0.01). Conclusions. Augmented sinus volume may change before implant placement. DBB offers greater volume stability during healing than composite grafts.


Asunto(s)
Sustitutos de Huesos/uso terapéutico , Imagenología Tridimensional/métodos , Seno Maxilar/diagnóstico por imagen , Seno Maxilar/cirugía , Elevación del Piso del Seno Maxilar/métodos , Tomografía Computarizada por Rayos X/métodos , Implantes Absorbibles , Femenino , Humanos , Masculino , Tamaño de los Órganos , Estudios Retrospectivos , Resultado del Tratamiento
7.
Case Rep Dent ; 2016: 1902089, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27429810

RESUMEN

Mandibular third molars are the most common impacted teeth. Mandibular first and second molars do not share the same frequency of occurrence. In rare cases the occlusal surfaces of impacted molars are united by the same follicular space and the roots pointing in opposite direction; these are called kissing molars. In some cases, a supernumerary fourth molar can be seen as unerupted and, in this case, such a supernumerary, deeply impacted fourth molar is seen neighboring kissing molars. The extraction of deeply impacted wisdom molars from the mandible may necessitate excessive bone removal and it causes complications such as damage to the inferior alveolar nerve and iatrogenic fractures of the mandible. This case report describes the use of the sagittal split osteotomy technique to avoid extensive bone removal and protect the inferior alveolar nerve during surgical extruction of multiple impacted teeth.

8.
J Oral Maxillofac Surg ; 74(12): 2370-2377, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27400145

RESUMEN

PURPOSE: To evaluate the morbidity of iliac block bone grafting performed under general anesthesia (GA) or combined spinal epidural anesthesia (CSEA). MATERIALS AND METHODS: We implemented a retrospective study including patients who underwent anterior iliac block bone grafting for deficient maxillary alveolar ridges. The anesthetic technique (GA or CSEA) was the primary predictor variable. The outcome variables were pain, gait disturbance, neurosensory disturbance (0 to 5 weeks), vomiting tendency (0 to 7 days), and postoperative hospitalization period (0 to 2 days). RESULTS: The sample comprised 22 patients, with 10 in the GA group and 12 in the CSEA group. No surgical complications except sensory disturbance in 2 patients were observed during the study period. Pain during initial healing (P < .001), the gait disturbance rate at 3 weeks after surgery (P = .003), and the vomiting tendency on the day of surgery (P < .001) were significantly higher in the GA group than in the CSEA group; all variables showed significant improvement with time in both groups. The postoperative hospitalization period was also significantly longer for the GA group than for the CSEA group (P < .001). No significant difference was observed between groups with regard to neurosensory disturbance. CONCLUSIONS: Iliac block bone grafting for deficient maxillary ridges can be successful under both GA and CSEA, although CSEA results in less pain and vomiting and early recovery, thus increasing patient comfort.


Asunto(s)
Injerto de Hueso Alveolar , Pérdida de Hueso Alveolar/cirugía , Anestesia Epidural , Anestesia General , Anestesia Raquidea , Trasplante Óseo , Ilion/trasplante , Adulto , Anciano , Injerto de Hueso Alveolar/métodos , Proceso Alveolar/cirugía , Trasplante Óseo/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Enfermedades Maxilares/cirugía , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Estudios Retrospectivos , Resultado del Tratamiento
9.
J Craniofac Surg ; 27(3): 805-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27092911

RESUMEN

Efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor-BB (rhPDGF-BB) delivered via absorbable collagen sponge (ACS) on bone formation was evaluated in guinea pig tibias. Three-millimeter-circular bone tibia defects were created in 24 guinea pigs assigned randomly to 4 groups according to the following defect filling materials: ACS only, rhBMP-2+ACS, rhPDGF-BB+ACS, or empty. New bone formation was evaluated histologically and histomorphometrically at 15 (early healing) and 45 days (late healing). Mean new bone per total defect area ratio was 0.73, 0.57, 0.43, and 0.42 in rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at early healing, respectively. During early healing, significantly more new bone formation was observed in rhBMP-2+ACS and rhPDGF-BB+ACS groups than in the control groups. New bone formation was significantly higher with rhBMP-2+ACS than with rhPDGF-BB+ACS. Mean new bone per total defect area ratio was 0.81, 0.86, 0.74, and 0.75 in the rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at late healing, respectively. During late healing, new bone formation was significantly higher in the rhPDGF-BB+ACS group relative to both control groups, but the results did not differ significantly from those in the rhBMP-2+ACS group. New bone formation in the rhBMP-2+ACS group did not change significantly between the healing periods. In the rhPDGF-BB+ACS group, however, new bone formation was significantly higher in the late healing period. Both growth factors accelerated new bone formation in the early healing period. Although rhBMP-2 was more effective in the early healing period, the effects of rhPDGF-BB were longer lasting.


Asunto(s)
Proteína Morfogenética Ósea 2/farmacología , Proteínas Proto-Oncogénicas c-sis/farmacología , Factor de Crecimiento Transformador beta/farmacología , Administración Tópica , Animales , Becaplermina , Trasplante Óseo , Colágeno , Cobayas , Proteínas Recombinantes/farmacología , Tibia/efectos de los fármacos , Tibia/patología , Tibia/cirugía , Cicatrización de Heridas
10.
J Craniofac Surg ; 27(2): e144-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26890457

RESUMEN

Extensive alveolar bone resorption because of pneumatized maxillary sinus is a common problem that limits dental implant placement. Maxillary sinus floor augmentation (MSFA) is an accepted treatment protocol that provides sufficient bone volume. The aim of this study was to evaluate the percentage of graft volume reduction following MSFA using cone beam computed tomography. In this retrospective study, cone beam computed tomography scans of MSFA were measured to evaluate the volume of the grafted sinus with deproteinized bovine bone (DBB), mineralized allograft (MA), or a mixture of MA and demineralized allograft as a composite. The volumetric changes in sinus augmentation between 2 weeks (T-I) and 6 months (T-II) after operation were analyzed. Thirty-nine patients were included in this study. The average percent volume reduction was 8.14 ±â€Š3.76%, 19.38 ±â€Š9.22%, and 24.66 ±â€Š4.68% for DBB, MA, and composite graft, respectively. A significant graft volume reduction was found between T-I and T-II for all groups (P < 0.01). The DBB group showed the least volume reduction (P < 0.01). Biomaterials can influence the bone graft volume change before implant placement. Deproteinized bovine bone may offer greater volume stability during healing than mineralized and composite allografts.


Asunto(s)
Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Materiales Biocompatibles , Trasplante Óseo/métodos , Tomografía Computarizada de Haz Cónico , Implantación Dental Endoósea/métodos , Imagenología Tridimensional , Seno Maxilar/diagnóstico por imagen , Seno Maxilar/cirugía , Elevación del Piso del Seno Maxilar/métodos , Adulto , Anciano , Femenino , Estudios de Seguimiento , Glicerol , Humanos , Masculino , Persona de Mediana Edad , Minerales , Estudios Retrospectivos
11.
J Istanb Univ Fac Dent ; 50(3): 21-31, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28955572

RESUMEN

PURPOSE: The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture. MATERIALS AND METHODS: This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group), while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group). All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ) values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible). RESULTS: In total, 103 implants (47 L, 56 M) were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively). There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001) and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks) at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points. CONCLUSION: Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

12.
Ir J Med Sci ; 184(2): 499-503, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24908058

RESUMEN

AIM: The aim of this study was to assess the relationship between the maternal superior mesenteric artery Doppler, pancreatic size and gestational diabetes mellitus (GDM). METHODS: Two hundred and fifty-eight consecutive, pregnant women between 20 and 22 weeks of gestation underwent routine fetal anomaly screening. All subjects underwent maternal superior mesenteric artery Doppler and pancreatic size measurement of head, corpus and tail during screening. Screening was done with 50 g glucose challenge test (GCT) at gestational age 24-28 weeks. The patients who were having an abnormal GCT were subjected to 100 g GCT. Subjects were divided into two groups such as pregnancies with gestational diabetes and normal pregnancies. Relationship between Doppler and pancreatic measurements with GDM was analyzed. RESULTS: Out of 258 screened pregnancies, 28 (10.9 %) were diagnosed as GDM. There were significant differences between GDM positive and negative cases in terms of pancreatic body size (17.5 vs. 14.4 mm, p = 0.05), superior mesenteric artery Doppler systolic/diastolic ratio (S/D) (4.2 vs. 3.4) and resistance index (RI) (0.72 vs. 0.68) values. Superior mesenteric artery Doppler S/D (AUC = 0.761, p < 0.001) and RI (AUC = 0.762, p < 0.001) indices were significant predictors for GDM. CONCLUSION: Superior mesenteric artery Doppler and pancreatic size evaluation may be utilized to detect abnormal glucose metabolism during pregnancy care.


Asunto(s)
Diabetes Gestacional/diagnóstico , Arteria Mesentérica Superior/diagnóstico por imagen , Páncreas/anatomía & histología , Adulto , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Tamaño de los Órganos , Páncreas/diagnóstico por imagen , Valor Predictivo de las Pruebas , Embarazo , Ultrasonografía Doppler , Resistencia Vascular , Adulto Joven
13.
Implant Dent ; 22(4): 406-13, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23823738

RESUMEN

PURPOSE: To assess the influence of different crown-implant (C/I) ratios and implant dimensions on periimplant stress in the partially edentulous posterior mandible by 3-dimensional finite element analysis (FEA). MATERIALS AND METHODS: Two implants were placed in the second premolar and first molar regions of the mandibular model. The implants were then splinted with a 2-unit fixed bridge. The influence of 3 parameters (C/I ratio, implant length, and implant diameter) on periimplant bone stress was then analyzed by using FEA. RESULTS: C/I ratios showed a direct relationship with periimplant bone stress, but the absolute height of the clinical crown had a much more significant influence. The implant length had less influence on the periimplant bone stress than the implant diameter. Lower stress values were detected in wide-diameter implants, even in scenarios involving long crowns. CONCLUSIONS: Crown height is a more important factor affecting the periimplant bone stress than the C/I ratio for splinted implant-supported crowns. Two-unit fixed restorations with high C/I ratios may be successfully used with wide-diameter implants in the posterior mandible.


Asunto(s)
Coronas , Implantes Dentales , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Dentadura Parcial Fija , Análisis de Elementos Finitos , Silicatos de Aluminio/química , Diente Premolar , Fenómenos Biomecánicos , Aleaciones de Cromo/química , Simulación por Computador , Diseño de Implante Dental-Pilar , Porcelana Dental/química , Módulo de Elasticidad , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Arcada Parcialmente Edéntula/fisiopatología , Mandíbula/fisiopatología , Modelos Biológicos , Diente Molar , Compuestos de Potasio/química , Estrés Mecánico , Propiedades de Superficie
14.
Int J Oral Maxillofac Implants ; 28(3): 815-23, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23748314

RESUMEN

PURPOSE: The aim of this prospective clinical trial was to compare the three-dimensional marginal bone level, implant stability, and peri-implant health of two types of submerged dental implants that were restored with matching or platform-switched abutments. MATERIALS AND METHODS: Twenty-five subjects were recruited (test group: 43 implants with internal conical connection and back-tapered collar carrying a platform-switched abutment; control group: 50 implants carrying a matched-platform abutment). Implant uncovering and conventional loading were performed after 3 months of healing, and the total observation time was 15 months. Marginal bone levels, resonance frequency analysis, insertion torque, and peri-implant health indices were recorded and analyzed statistically. RESULTS: The cumulative implant survival rate was 100%. At the second-stage surgery, bone levels were similar between groups. One year after loading, mean crestal bone loss was 0.35 ± 0.13 mm for test implants and 0.83 ± 0.16 mm for control implants, a significant difference. Primary stability was significantly higher in the test group than in the control group, but this difference disappeared after 3 months of healing prior to loading. Between-group differences for peri-implant health indices were negligible. CONCLUSIONS: Both implant systems had the same survival rates. Implants with a built-in platform switch and conical connection with back-tapered collar design achieved higher primary stability at insertion and less bone resorption after 15 months.


Asunto(s)
Pérdida de Hueso Alveolar/etiología , Diseño de Implante Dental-Pilar/métodos , Implantación Dental Endoósea/métodos , Implantes Dentales , Adulto , Pérdida de Hueso Alveolar/patología , Pilares Dentales , Diseño de Prótesis Dental , Fracaso de la Restauración Dental/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Torque , Adulto Joven
15.
J Prosthodont ; 22(2): 112-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23387964

RESUMEN

PURPOSE: To measure and compare the retentive strength of cements specifically formulated for luting restorations onto implant abutments and to investigate the effect of varying cement gap on retention strength of implant-supported crowns. MATERIALS AND METHODS: Standard titanium abutments were scanned by means of a 3D digital laser scanner. One hundred and sixty standard metal copings were designed by a Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) system with two cement gap values (20 and 40 µm). The copings were cemented to the abutments using the following eight cements with one being the control, zinc oxide temporary cement, while the other seven were specifically formulated implant cements (n = 10): Premier Implant Cement, ImProv, Multilink Implant, EsTemp Implant, Cem-Implant, ImplaTemp, MIS Crown Set, and TempBond NE. The specimens were placed in 100% humidity for 24 hours, and subjected to a pull-out test using a universal testing machine at a 0.5 mm/min crosshead speed. The test results were analyzed with two-way ANOVA, one-way ANOVA, post hoc Tamhane' s T2, and student's t-tests at a significance level of 0.05. RESULTS: Statistical analysis revealed significant differences in retention strength across the cement groups (p < 0.01). Resin-based cements showed significantly higher decementation loads than a noneugenol zinc oxide provisional cement (TempBond NE) (p < 0.01), with the highest tensile resistance seen with Multilink Implant, followed by Cem-Implant, MIS Crown Set, ImProv, Premier Implant Cement, EsTemp Implant, and ImplaTemp. Increasing the cement gap from 20 to 40 µm improved retention significantly for the higher strength cements: Multilink Implant, Premier Implant Cement, ImProv, Cem-Implant, and MIS Crown Set (p < 0.01), while it had no significant effect on retention for the lower strength cements: EsTemp Implant, ImplaTemp, and TempBond NE (p > 0.05). CONCLUSIONS: Resin cements specifically formulated for implant-supported restorations demonstrated significant differences in retention strength. The ranking of cements presented in the study is meant to be an arbitrary guide for the clinician in deciding the appropriate cement selection for CAD/CAM-fabricated metal copings onto implant abutments with different luting space settings.


Asunto(s)
Coronas , Cementos Dentales/química , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Resinas Acrílicas/química , Diseño Asistido por Computadora , Pilares Dentales , Aleaciones Dentales/química , Materiales Dentales/química , Retención de Prótesis Dentales , Análisis del Estrés Dental/instrumentación , Humanos , Humedad , Imagenología Tridimensional/métodos , Rayos Láser , Cementos de Resina/química , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción , Factores de Tiempo , Titanio/química , Uretano/química , Óxido de Zinc/química
16.
Implant Dent ; 19(6): 498-508, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21119354

RESUMEN

PURPOSE: This finite element analysis was conducted to determine changes in stress concentration in relation to different alveolar arch shapes of the maxilla. MATERIALS AND METHODS: Five different maxillary alveolar arch shape measurements coded as shortest ellipsoid shape and medium width, longest ellipsoid shape and narrow, U-shaped long and narrow, U-shaped short and wide, and U-shaped medium length and medium width were obtained, and 5 different implant distribution strategies coded on the basis of a tooth number as 3,4,5; 2,3,4; 1,3,5; and 2,4,5 (total of 6 implants) and 2,3,4,5 (total of 8 implants) were plotted in each of the 5 maxillary arch models. The implants were assumed to support a 12-unit bridge with first molars region being the cantilever area. Combination of 5 different arch shapes, 5 different implant distributions, and 2 different loading points (anterior and posterior) led to 50 different simulated scenarios that are all solved and compared. RESULTS: In case of either anterior or posterior loading, the most favorable implant distribution strategies for the arch models are as follows: 2,4,5 and 2,3,4,5 for longest ellipsoid shape and narrow; 2,4,5 and 2,3,4,5 for shortest ellipsoid shape and medium width; 1,3,5 and 2,3,4,5 for U-shaped long and narrow; 2,3,4,5 and 2,4,5 for U-shaped medium length and medium width; and 1,3,5 and 2,3,4,5 for U-shaped short and wide. CONCLUSIONS: Distribution of implants in 2,4,5 order seemed to be fairly favorable for ideal stress distribution in all simulated models.


Asunto(s)
Arco Dental/anatomía & histología , Implantación Dental Endoósea , Prótesis Dental de Soporte Implantado , Análisis del Estrés Dental , Arcada Edéntula/fisiopatología , Fenómenos Biomecánicos , Fuerza de la Mordida , Simulación por Computador , Implantación Dental Endoósea/métodos , Diseño de Prótesis Dental , Análisis del Estrés Dental/métodos , Análisis de Elementos Finitos , Humanos , Maxilar/fisiopatología , Modelos Dentales
17.
Transplant Proc ; 40(1): 255-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18261601

RESUMEN

OBJECTIVE: The surgical techniques was first described by Lower and Shumway for cardiac transplantation have not changed for many years; they are still being commonly used worldwide despite recently presented alternatives. We sought to evaluate the surgical complications among our cardiac transplantation patients in whom we performed the standard technique. PATIENTS AND METHODS: The standard biatrial anastomosis technique was used in 13 patients who have a mean follow-up of 18.6 (1 to 38) months. During the follow-up, echocardiographic assessment was performed to evaluate left and right atrial diameters, tricuspid and mitral valve regurgitation, interatrial septum, and suture lines. Elecotrocardiograms were evaluated for arryhthmia and pacemaker requirements in the midterm. RESULTS: The mean left and right atrial diameters were measured as 40.5 (32 to 57) x 66.6 (48 to 78) and 37.9 (32 to 43) x 56.3 (48 to 69) mm, respectively. The jet area was calculated at less than 5 cm(2) for mitral and tricuspid valve regurgitation, which can be defined as "mild" regurgitation. There was no increase in the degree of regurgitation of both atrioventricular valves during the follow-up period. In one patient, a thrombus was detected in the suture line; there was a nonsignificant left to right shunt in another patient. A temporary pacemaker was indicated in two patients. Atrial fibrillation was detected in three patients, who responded to medical therapy. During the follow-up atrial fibrillation developed in one patient. CONCLUSION: The cardiac transplantation operation using the standard technique may result in atrial dysfuntion due to deformation of atrial integrity and geometry. However, when we evaluated our results, we concluded that the standard surgical technique was a safe, simple, effective, and feasible method.


Asunto(s)
Trasplante de Corazón/efectos adversos , Complicaciones Posoperatorias/epidemiología , Adolescente , Adulto , Niño , Estudios de Seguimiento , Trasplante de Corazón/métodos , Humanos , Tiempo de Internación , Persona de Mediana Edad , Complicaciones Posoperatorias/clasificación , Factores de Tiempo
18.
Transplant Proc ; 40(1): 259-62, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18261602

RESUMEN

OBJECTIVE: Cardiac transplantation is an important treatment option that increases the survival and decreases the limitations in effort capacity among patients with end-stage heart disease. In this study we have presented the midterm results of 13 patients who underwent cardiac transplantation between 2003 and 2007. PATIENTS AND METHODS: There were 10 male and three female patients of mean age of 32 +/- 13.27 years (12 to 54). In one patient, we performed combined cardiac and renal transplantation. Ischemic cardiac disease was present in six patients and cardiomyopathy in seven patients. The mean age of the donors was 23.3 +/- 11.8 years (12 to 46). Corticosteroids, cyclosporine, and mycophenolate mofetil were used for immunosuppression. Sirolimus was employed in five cases due to impaired renal function. Patients were followed by echocardiography, endomyocardial biopsy, and dobutamine stress echocardiography. RESULTS: The mean follow-up was 18.6 +/- 13.4 (1 to 38) months. In four patients, there was grade IIIA (II-R) rejection. In five patients, tacrolimus or cyclosporine was replaced with sirolimus due to elevated creatinine levels. Dobutamine stress echocardiography was positive in one patient, who displayed a severe left main coronary artery lesion. There was no operative mortality. There was only one hospital mortality (7.6%). Two patients died in the midterm. The overall mortality on follow-up was 3 (23.1%). The survival rates in the first, second, and third years were 92%, 88%, and 75%, respectively. Ejection fraction were more than 50%; all of posttransplant survivors showed good effort capacity. CONCLUSION: Cardiac transplantation is a definitive, safe, and effective treatment for patients with end-stage heart failure.


Asunto(s)
Trasplante de Corazón/fisiología , Adolescente , Adulto , Niño , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Cardiopatías/clasificación , Cardiopatías/cirugía , Trasplante de Corazón/inmunología , Trasplante de Corazón/mortalidad , Humanos , Inmunosupresores/uso terapéutico , Tiempo de Internación , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
19.
Transplant Proc ; 40(1): 263-6, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18261603

RESUMEN

BACKGROUND: Graft coronary artery disease, a serious problem after orthotopic heart transplantation (OHT), has multifactorial etiologies with dyslipidemia as one of the major risk factors. In this study we examined lipid profiles and drug therapy of our patients before and after OHT. METHODS: Thirteen patients who underwent OHT at our center were enrolled in the study. We noted the patients' clinical and demographic data and current medications as well as pre- and postoperative lipid values. RESULTS: The mean age of the study group was 32.0 +/- 13.2 years with three women. Compared to the preoperative values, significant increases were detected in the mean levels of low-density lipoprotein (LDL) (81.3 +/- 29.1 vs 103.5 +/- 22.2 mg/dL; P = .03) and total cholesterol (142.0 +/- 58.5 vs 184.0 +/- 37.8 mg/dL; P = .02), while triglyceride (113.5 +/- 67.3 vs 137.0 +/- 69.9 mg/dL; P = .1) and high-density lipoprotein (42.7 +/- 10.2 vs 48.7 +/- 14.4 mg/dL; P = .2) levels did not change significantly at 2 to 3 months postoperatively. On follow-up eight patients were prescribed a statin (atorvastatin in all), one of whom was on ezetimibe in addition to statin and one, fenofibrate. The patients tolerated lipid-lowering agents well; no significant side effect was noted. CONCLUSION: These findings demonstrated increased lipid values, mainly in total cholesterol and LDL levels, after OHT. Regarding the importance of dyslipidemia as a major atherosclerotic risk factor, we believe that statins in the absence of a contraindication should be part of the treatment protocol in patients with a transplanted heart.


Asunto(s)
Trasplante de Corazón , Lípidos/sangre , Adulto , Colesterol/sangre , Creatina Quinasa/sangre , Dislipidemias/epidemiología , Femenino , Enfermedad Injerto contra Huésped/epidemiología , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Cuidados Preoperatorios
20.
Transplant Proc ; 40(1): 324-5, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18261619

RESUMEN

BACKGROUND: The use of hearts for cardiac transplantation from donors with brain death due to exposure to high concentrations of carbon monoxide is still under discussion. In this short report we have presented a patient who underwent a successful cardiac transplantation from a brain-dead donor who had cardiopulmonary resuscitation after carbon monoxide intoxication. METHOD: A standard biatrial anastomosis technique was used in our patient. The transplantation was uneventful with donor ischemic time of 180 minutes. The patient was treated with mechanical ventilation for 72 hours. The donor liver biopsy during harvesting did not reveal irreversible changes. Although the donor had a history of cardiopulmonary resuscitation, the left ventricular ejection fraction was 55% and the echocardiographic evaluation revealed normal cardiac contractions with acceptable hemodynamic parameters. Positive inotropic support was needed in the early postoperative period. We did not observe any changes related to intoxication in the endomyocardial biopsy. CONCLUSIONS: We concluded that successful heart transplantation can be performed using hearts from patients succumbing to carbon monoxide poisoning in the presence of adequate cardiac functional parameters. This group will increase the number of cardiac transplantations and decrease the incidence of deaths among patients on transplantation lists.


Asunto(s)
Intoxicación por Monóxido de Carbono , Cardiomiopatía Dilatada/cirugía , Trasplante de Corazón , Donantes de Tejidos , Adulto , Muerte Encefálica , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
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