ABSTRACT
Aim: The record of path of insertion on the dental cast is part of the dentist's work authorization to the dental laboratory technician. The path of insertion record enables the dental technician to replace the cast on a surveyor in the same position that the dentist selected. Analysis of factors that influence the path of insertion should determine a path of insertion that will reduce the potential for dislodgement and promote stability of removable partial denture (RPD). Materials and Methods: The recording of the relation of a cast to a dental surveyor and the transfer of this relationship to the dental laboratory may be done by tripodization, by scoring the base of the cast, or by cementing a reference pin on the cast. Conclusion: Recording the established path of insertion can be difficult when the procedure uses a cemented pin and the casts are mounted in an articulator. This article describes a procedure for innovative dowel pin and sleeve device to record the path of insertion of RPDs, which serves the same purpose as the cemented pin but can be easily removed and replaced.
Subject(s)
Dental Health Services , Denture, Partial, Removable/instrumentation , Denture, Partial, Removable/methods , Post and Core Technique/instrumentation , Post and Core Technique/methodsABSTRACT
Aim: Compare the effect of three post designs on the fracture resistance and failure modes of composite core - fiber post - crownless tooth sets. Materials and Methods: Ninety bovine incisors were selected and divided into nine groups of 10 specimens. The teeth were assigned to three groups based on the post design: Cylindrical, tapered, and double-tapered. Each group was subdivided into three subgroups in accordance with the diameter of the post: Small (No.1), medium (No.2), and large (No.3). The Panavia F system was used for post cementation. The specimens were mounted in acrylic resin blocks with a layer of silicone rubber covering the roots. A universal testing machine compressively loaded the specimens from the palatal side at a crosshead speed of 1 mm/min and at an angle of 135Ί to the long axis of the teeth, until failure occurred. The failure mode was determined by a stereomicroscope inspection of all the specimens. Data were analyzed by one-way ANOVA and the Tukey test (P < 0.05). Results: The fracture resistance was affected by the type of post (P < 0.0001). A narrower diameter for all of the post systems allowed for higher resistance. The main failure mode in the large cylindrical group was catastrophic fractures, while the main failures in the other eight groups were favorable. Conclusion: Narrower diameter posts showed higher fracture resistance. The dominant failure pattern was repairable fracture, except for those with large cylindrical groups.
Subject(s)
Animals , Cattle , Crowns , Dental Stress Analysis , Glass , Incisor/physiopathology , Materials Testing , Models, Animal , Post and Core Technique/instrumentation , Post and Core Technique/methods , Tooth Fractures/physiopathologyABSTRACT
Todos los dientes tratados endodónticamente necesitan ser restaurados; en muchos de los casos estará indicada la colocación de un poste, ya sea prefabricado o colado. Crear el espacio para poste requiere eliminar parte de la gutapercha y del cemento sellador, así como manipular el conducto radicular, con lo que se incrementa el riesgo de debilitar o perforar la raíz. El objetivo de la presente revisión es ofrecer un punto de vista de la forma en que la preparación del espacio para un poste intrarradicular puede provocar la filtración coronal de bacterias que conllevarían al fracaso del tratamiento endodóntico realizado
Subject(s)
Tooth Preparation/methods , Root Canal Therapy , Post and Core Technique/methods , Tooth, Nonvital , Cementation/methods , Dental Impression Technique , Dental Pulp Cavity , Dental Restoration Failure , Dental Leakage/etiology , Dental Leakage/physiopathology , Tooth, NonvitalABSTRACT
Post and core treatment is a basic preprosthetic skill in fixed prosthetics and serves as a foundation for many restorative plans. At present it is disturbing for the clinical dentist to read new research statements that traditional methods for restoring pulpless teeth are outmoded. Actually in many cases these promote tooth breakdown. The reality is that the guidelines for post and and core treatment are in controversy. This paper reviews basic concepts for the dentists to consider when making a decision about post and core build up. This will provide an additional aid in making clinical decisions for the restoration of endodontically treated teeth