Case report : vertical preparation protocol for veneers

The biologically oriented preparation technique (BOPT) consists of a vertical preparation of the tooth that involves a reduction to zero of the emergence anatomy, the creation of a new finish area, and immediate temporization, so that the gingiva is supp

Effect of platform switching on the peri-implant bone: a finite element study

Background: There exists a relation between the presence and location of the micro-gap and the loss of peri-implant bone. Several authors have shown that the treatments based on the use of platform switching result in less peri-implant bone loss and an increased tissue stability. The purpose of this study was to analyse the effect of the platform switching on the distribution of stresses on the peri-implant bone using the finite element method. Material and Methods: A realistic 3D full-mandible finite element model representing cortical bone and trabecular bone was used to study the distribution of the stress on the bone induced by an implant of diameter 4.1 mm. Two abutments were modelled. The first one, of diameter 4.1 mm, was used in the reference model to represent a conventional implant. The second one, of diameter 3.2 mm, was used to represent the implant with platform switching. Both models were subjected to axial and oblique masticatory loads. Results: The analyses showed that, although no relevant differences can be found for the trabecular bone, the use of platform switching reduces the maximum stress level in the cortical bone by almost 36% with axial loads and by 40% with oblique loads. Conclusions: The full 3D Finite Element model, that can be used to investigate the influence of other parameters (implant diameter, connection, ...) on the biomechanical behaviour of the implant, showed that this stress reduction can be a biomechanical reasons to explain why the platform switching seems to reduce or eliminate crestal bone resorption after the prosthetic restoratio

Comparison of the retention strengths of three complete denture adhesives : an in vivo study

Statement of problem: One of the main problems posed by complete dentures is retention and stability. In order to solve this problem, dentists and the dental industry for a long time have attempted to improve denture adhesion by developing a range of ?glues? of highly varied composition and efficacy. Purpouse: The present in vivo clinical study evaluates whether the adhesives used to improve complete denture retention are truly effective and able to increase denture adhesion to the mucosa covering the edentulous alveolar ridge of the mandibular dentures. Material and Methods: An in vivo clinical study is made of 30 patients with complete mandibular dentures to evaluate the retention afforded by three commercial complete denture adhesives (Benfix®, Fittydent® and Supercorega®). A spring scale was used to measure retention strength (in grams). The purpose was to determine whether the use of complete denture adhesives is effective, and to establish which commercial brands offer the highest retention strengths. Results and Conclusion:The results obtained indicate that retention is enhanced by the use of such adhesives, and that Fittydent® offers the best retention performance, followed by Benfix® and Supercorega®. Clinical implications: the study of denture adhesives and his efficiency are necessary to improve the edentulous patient satisfaction. More in vivo investigations are necessary in dental literatur

Clinical effect of diode laser on peri-implant tissues during non-surgical peri-implant mucositis therapy : randomized controlled clinical study

The aim of this study is to evaluate the response to the non-surgical treatment of peri-implant mucositis using the diode laser as an adjuvant therapy in patients with implant-supported restorations, in terms of clinical variables, with respect to those patients in whom conventional non-surgical therapy is used. Randomized controlled clinical trial with simple blind 3 months follow-up. Two groups of patients were established, the non-surgical mechanical debridement of the affected implants was performed in the control group (n = 34) and the diode laser therapy was also performed in the test group (n = 34). The implant was considered the study subject; the variables considered were plaque index, bleeding on probing depth, depth of probing and recession of the peri-implant mucosa. The t-Student test was used to establish the intergroup statistical differences and the analysis of variance (ANOVA) was used to measures intragroup differences over time. In the revaluation at 6 weeks, we observed statistically significant differences (p<0.05) between the variables of plaque index and depth of probing between both groups. The test group obtained an average of 0.248 ± 0.3155 in plaque index and 0.833 ± 0.374mm in the depth of probing compared to the results obtained in the control group that was 0.558 ± 0.526 and 1,137 ± 0.222mm respectively. In the 3-month reevaluation, was also obtained great statistical significance between both groups for bleeding on probing (p<0.001), with values of 0.568 ± 0.282 for the control group and 0.480 ± 0.336 for the test group. The use of diode laser as an adjunctive therapy to the conventional treatment of peri-implant mucositis showed promising results, being more effective reducing the inflammation of the peri-implant tissue, positioning itself as a valuable tool for the treatment of peri-implant pathologies

Telescopic crowns in adult case with lip and palate cleft : update on the etiology and management

Lip and palatal clefts are among the most important congenital craniofacial malformations to be taken into account in general dental practice, due to their high incidence and important repercussions upon the oral cavity. The underlying causes are genetic and fundamentally environmental, and the disorders manifest as early as in the embryonic period. Males are predominantly affected, with a 7:3 ratio versus females. Our patient, a 20-year-old male, presented the most common association, i.e., total unilateral hare lip with palatal cleft. A description is provided of the treatment for his dental problem, together with an update on the etiology and management of adults with malformations of this kind

Med Oral Patol Oral Cir Bucal

Abstract Objective: The purpose of this study was to determine whether the bond of veneering porcelain to a ceramic core in bilayered ceramics was similar to that of the metal ceramic control of well known behaviour. Study design: Six groups of nine specimens each were fabricated, whose dimensions were 15 mm long and 8 mm in diameter at the core, and 2 mm long and 8 mm in diameter for the veneer. The groups were GR. 1 (control group): CrNi alloy/d.SIGN (Ivoclar), GR. 2: IPS e.maxPress/IPS e.maxCeram (Ivoclar), GR. 3: IPS e.maxZirCad/ IPS e.maxZirPress (Ivoclar), GR. 4: IPS e.maxZirCad/IPS e.maxCeram (Ivoclar), GR. 5: Lava Frame (3M ESPE)/ Lava Ceram (3M ESPE) and GR. 6: Lava Frame (3M ESPE)/IPS e.maxCeram (Ivoclar). A shear strength test was used in all samples with a universal testing machine. The chosen crosshead speed was of 0.50 mm/min. The obtained results were analyzed using a one way analysis of variance test (ANOVA) to determine whether significant differences existed between the groups (p&lt;0.05). A Student Newman-Keuls multiple comparisons test was used. Results: GR. 1: 13.45 MPa, GR. 2: 24.20 MPa, GR. 3: 12.70 MPa, GR. 4: 7.86 MPa, GR. 5: 10.20 Mpa and GR. 6: 4.62 Mpa. Conclusions: The bond strength of group 1 (control) was similar to groups 3 and 5. Group 2, whose core and veneer are both porcelains with a similar chemical composition, with silica as their main component, achieved the best adhesive results between both porcelains. The technique on zirconia cores that showed the higher results was the pressed technique. The lowest results were for the group using porcelains from different manufacturers

Estudio mediante elementos finitos del comportamiento biomecánico de diferentes interfases implante-pilar e influencia de la pérdida de hueso periimplantario

Tesis inédita presentada en la Universidad Europea de Madrid. Facultad de Ciencias Biomédicas. Programa de Doctorado en Odontología AvanzadaEl proceso de la osteointegración ha permitido que hoy en día los tratamientos implantológicos sean altamente predecibles. Sin embargo, los estudios en los últimos años se centran, entre otros, en averiguar las causas por las cuáles, una vez integrado el implante en el hueso, se llevan a cabo una serie de procesos que conllevan la pérdida del hueso periimplantario, lo que puede acabar con la pérdida del implante. Hay varias variables que pueden intervenir en dicha pérdida ósea marginal. Se han estudiado algunas de estas variables aplicando el método de los elementos finitos, para observar la distribución de tensiones que se generan con la carga sobre diferentes diseños de interfase implante-pilar y valorar los cambios que se producen tras la pérdida ósea generada por las modificaciones del ancho biológico. Se analizaron varios modelos con diferente diámetro de implante, tipo de plataforma (con y sin platform switching), tipo de conexión (externa o interna) y diferente nivel de hueso respecto al implante, aplicándoles dos cargas, vertical y oblicua. Los resultados se exponen en forma de gráficas de tensiones donde observamos cómo se distribuían las mismas según los diferentes modelos estudiados en cada uno de los elementos analizados independientemente, complejo tornillo-pilar, implante, hueso cortical y hueso trabecular. Tras la discusión de nuestros resultados con los de otros autores llegamos a las conclusiones de nuestra investigación. Así hemos observado que a mayor diámetro del implante obtenemos mejor distribución de tensiones en todos los elementos estudiados. También el empleo del platform switching tiene un efecto beneficioso sobre el hueso cortical y trabecular. Cuando no se utiliza modificación de plataforma, con la conexión interna hay menores valores de tensión sobre hueso cortical que con la conexión externa. Se observa menor despegue en la interfase implante-pilar al utilizar conexión interna con platform switching al compararlo con la conexión externa. La reabsorción ósea previa afecta negativamente a la distribución de tensiones en todos los elementos, salvo en el hueso cortical, siendo la afectación más llamativa a nivel del hueso trabecular. Los resultados de carga oblicua y vertical se dirigen, en general, hacia el mismo sentido. [Resumen Teseo].UE

Effect of platform switching on the peri-implant bone: A finite element study

There exists a relation between the presence and location of the micro-gap and the loss of peri implant bone. Several authors have shown that the treatments based on the use of platform switching result in less peri-implant bone loss and an increased tissue stability. The purpose of this study was to analyse the effect of the platform switching on the distribution of stresses on the peri-implant bone using the finite element method. A realistic 3D full-mandible finite element model representing cortical bone and trabecular bone was used to study the distribution of the stress on the bone induced by an implant of diameter 4.1 mm. Two abutments were modelled. The first one, of diameter 4.1 mm, was used in the reference model to represent a conventional implant. The second one, of diameter 3.2 mm, was used to represent the implant with platform switching. Both models were subjected to axial and oblique masticatory loads. The analyses showed that, although no relevant differences can be found for the trabecular bone, the use of platform switching reduces the maximum stress level in the cortical bone by almost 36% with axial loads and by 40% with oblique loads. The full 3D Finite Element model, that can be used to investigate the influence of other parameters (implant diameter, connexion type, …) on the biomechanical behaviour of the implant, showed that this stress reduction can be a biomechanical reasons to explain why the platform switching seems to reduce or eliminate crestal bone resorption after the prosthetic restoration.Sin financiaciónNo data (2016)UE

Bond strength evaluation of the veneering-ceramics bonds

Objective: The purpose of this study was to determine whether the bond of veneering porcelain to a ceramic core in bilayered ceramics was similar to that of the metal ceramic control of well known behaviour. Study design: Six groups of nine specimens each were fabricated, whose dimensions were 15 mm long and 8 mm in diameter at the core, and 2 mm long and 8 mm in diameter for the veneer. The groups were GR. 1 (control group): CrNi alloy/d.SIGN (Ivoclar), GR. 2: IPS e.maxPress/IPS e.maxCeram (Ivoclar), GR. 3: IPS e.maxZirCad/ IPS e.maxZirPress (Ivoclar), GR. 4: IPS e.maxZirCad/IPS e.maxCeram (Ivoclar), GR. 5: Lava Frame (3M ESPE)/ Lava Ceram (3M ESPE) and GR. 6: Lava Frame (3M ESPE)/IPS e.maxCeram (Ivoclar). A shear strength test was used in all samples with a universal testing machine. The chosen crosshead speed was of 0.50 mm/min. The obtained results were analyzed using a one way analysis of variance test (ANOVA) to determine whether significant differences existed between the groups (p<0.05). A Student Newman-Keuls multiple comparisons test was used. Results: GR. 1: 13.45 MPa, GR. 2: 24.20 MPa, GR. 3: 12.70 MPa, GR. 4: 7.86 MPa, GR. 5: 10.20 Mpa and GR. 6: 4.62 Mpa. Conclusions: The bond strength of group 1 (control) was similar to groups 3 and 5. Group 2, whose core and veneer are both porcelains with a similar chemical composition, with silica as their main component, achieved the best adhesive results between both porcelains. The technique on zirconia cores that showed the higher results was the pressed technique. The lowest results were for the group using porcelains from different manufacturers