Precision Attachments Research Articles

Investigation of a myxoma in the right ventricular outflow tract

We describe an atypical myxoma in the right ventricular outflow tract of a 12-year old girl. After identification using echocardiography, we assessed its precise location and attachments by magnetic resonance imaging. Subsequent to surgical removal, histology confirmed the myxomatous nature of the tumour.

Removable Partial Prosthesis (RPP) with acrylic resin flange for the mandibular guidance therapy

Patients undergoing hemimandibulectomy suffer from mandibular deviation. The purpose of this article is to describe a new therapeutic possibility for the prosthetic management of these patients using only one device both for physiotherapy and eating. A 56-year-old man's pre-existing mandibular removable partial prosthesis was modified to use as a partial prosthesis as a device to correct mandibular deviation. In fact, two precision attachments patrix were inserted into buccal surface of partial prosthesis base and corresponding matrix were inserted into a transparent acrylic resin guide-flange. In this way the patient can use only one prosthesis both for physiotherapy and eating simply inserting and removing the guide flange. The transparent resin employ is important for the day by day use. This technique permits to use only one device both for mechanical correction of mandibular deviation and masticatory function while literature shows that two different devices are usually used in patients with mandibular deviation to satisfy both these functions.

Interosseous Membrane of the Forearm: An Anatomical Study of Ligament Attachment Locations

The interosseous membrane (IOM) of the forearm is a stout ligamentous complex that reportedly comprises several ligamentous components. The purpose of this cadaveric study was to define all IOM ligaments and to clarify the precise attachment locations. Thirty forearms from 15 embalmed cadavers were used. After dissection, all IOM ligaments were identified, and attachments were measured from the tip of the radial styloid or the ulnar head. Attachment locations were represented as a percentage of total bone length from the distal end of the radius or ulna. The IOM included 5 kinds of ligaments: central band, accessory band, distal oblique bundle, proximal oblique cord, and dorsal oblique accessory cord. The most distal and proximal ends of the radial origin of the central band were 53% and 64% of total radial length from the tip of the radial styloid, whereas those of the ulnar insertion were 29% and 44% of total ulnar length from the ulnar head. The center point of the radial origin and ulnar insertion of the accessory band were 37% and 23%, respectively. The center points of the ulnar origins and radial insertions were 15% and 10% for the distal oblique bundle; 80% and 79% for the proximal oblique cord; and 64% and 62% for the dorsal oblique accessory cord, respectively. The present study clarified precise attachment locations of all representative IOM ligaments. This information will be useful in planning proper graft placement in ligament reconstruction surgery and for future biomechanics research into the function of the IOM ligaments.

Análise do Desgaste de Attachments com Microscopia Electrónica de Varrimento

ObjectivesThe main objectives of this study were the verification and qualitative comparative analysis of superficial wear, resultant of attrition between different precision attachments and distinct metal alloys. Material and methodsThree types of attachments (ANC94 L 110®, Klinat L 90® and ARS 88®) with matrix fused in palladium- gold metal alloy (Degupal G®), two metal bases, chromo-cobalt (Ugirex C®) and chromo-nickel (Rexilium III®), where used. All attachments where submitted to 4400 insertion/disensertion cycles in a stress simulator, under continuous bidistilled water jet. ResultsSuperficial electronic microscope (SEM) scanning analysis of the attachment surfaces, revealed signs of compression, scrapping and erosion, to some degree, in all observed samples. Signs of superficial wear were observed on all surfaces subject to attrition, independent of types of attachment and alloys utilized. As to the patrix, evident signs of superficial wear including scrapping, more or less deep grooving as well as material loss, where observed. ConclusionsNo significant differences in degree of superficial wear were observed, either in relation to type of alloy or components of the three types of attachments under study.

Effect of simulating static magnetic field of magnetic attachment on osteoblastic morphology and surface ultrastructure

To investigate effects of the static magnetic field (SMF) generated by dental magnetic attachment on osteoblastic morphology and surface ultrastructure. The in vitro cultured rat osteoblasts were exposed continuously to 12.5 mT, 125 mT, and 250 mT static magnetic fields for 1, 3, 5, and 7 days. After exposed in SMF, osteoblasts were observed under a phase contrast microscope, and then HE stained and observed under a light microscope. In addition, the cells were observed under a scanning electron microscope (SEM). By continuous exposure, the different intensities of SMF exposure did not change the vital osteoblast growth pattern or distribution. The SEM photos showed that there were certain changes in cellular microstructures for osteoblasts after exposed to 12.5 mT for 5 to 7 days, as well as 125 mT and 250 mT for 3 to 7 days. The more exposure time increased, the more microvesicles on the surfaces of cells were observed. Continuous SMF-stimulation could not affect the shape, distribution, and growth pattern of osteoblasts. The SMF of magnetic attachments could lead to certain changes in surface ultrastructures of osteoblasts in this study.

Site-selective glycosylation of proteins: creating synthetic glycoproteins

In higher organisms, the functions of many proteins are modulated by post-translational modifications (PTMs). Glycosylation is by far the most diverse of the PTM processes. Natural protein production methods typically produce PTM or glycoform mixtures within which function is difficult to dissect or control. Chemical tagging methods allow the precise attachment of multiple glycosylation modifications to bacterially expressed (bare) protein scaffolds, allowing reconstitution of functionally effective mimics of glycoproteins in higher organisms. In this way combining chemical control of PTM with readily available protein scaffolds provides a systematic platform for creating probes of protein-PTM interactions. This protocol describes the modification of Cys residues in proteins using glycomethanethiosulfonates and glycoselenenylsulfides and the modification of azidohomoalanine residues, introduced by Met replacement using auxotrophic Met(-) Escherichia coli strains, with glycoalkynes and the combination of these techniques for the creation of dual-tagged proteins. Each glycosylation procedure outlined in this protocol can be achieved in half a day.

Heightened Telescopic Copings in Cleft Palate Rehabilitation: A Case Report

To increase retention of overdentures in cleft palate patients by means of heightened telescopic copings with a newly designed attachment. In this study, a "precision attachment" is described to develop the stability and retention of telescopic overdentures. A cleft palate patient was treated with a newly designed overdenture. Intraoral examination revealed poor tooth structure and retention. Therefore, a new semiprecision attachment was designed in order to increase retention and stabilization. The patient's tolerance was increased with the new overdenture.

O25 Use of precision attachments to enhance the retention of the maxillofacial prosthetic obturator

O25 Use of precision attachments to enhance the retention of the maxillofacial prosthetic obturator

Nursing points about using the polysiloxane impression material in the repair of the precise attachment

目的 探讨硅橡胶印模材料在精密附着义齿修复中的应用价值.方法使用Rapid硅橡胶印模材料为33例患者制取37副工作印模,使用藻酸盐印模材料制取29副非工作印模.结果37副工作印模均一次操作完成,符合临床要求,29副非工作印模中有4例通过二次印模才达到要求.结论Rapid硅橡胶印模材料在精密附着体修复中应用效果好,具有体积稳定性好、操作简便的特点。

Elucidation of N-Glycosylation Sites on Human Platelet Proteins

Among known platelet proteins, a prominent and functionally important group is represented by glycoprotein isoforms. They account e.g. for secretory proteins and plasma membrane receptors including integrins and glycoprotein VI as well as intracellular components of cytosol and organelles including storage proteins (multimerin 1 etc.). Although many of those proteins have been studied for some time with regard to their function, little attention has been paid with respect to their glycosylation sites. Here we report the analysis of N-glycosylation sites of human platelet proteins. For the enrichment of glycopeptides, lectin affinity chromatography as well as chemical trapping of protein bound oligosaccharides was used. Therefore, concanavalin A was used for specific interaction with carbohydrate species along with periodic acid oxidation and hydrazide bead trapping of glycosylated proteins. Derivatization by peptide:N-glycosidase F yielded deglycosylated peptides, which provided the basis for the elucidation of proteins and their sites of modification. Using both methods in combination with nano-LC-ESI-MS/MS analysis 70 different glycosylation sites within 41 different proteins were identified. Comparison with the Swiss-Prot database established that the majority of these 70 sites have not been specifically determined by previous research projects. With this approach including hydrazide bead affinity trapping, the immunoglobulin receptor G6f, which is known to couple to the Ras-mitogen-activated protein kinase pathway in the immune system, was shown here for the first time to be present in human platelets.

Ross Procedure in a Quadricuspid Aortic Valve

A quadricuspid aortic valve is a rare congenital cardiovascular abnormality, and when present, it is associated with aortic valve regurgitation. If aortic valve replacement is required, mechanical or biological prostheses are used. We report the case of a patient with a severely regurgitant quadricuspid aortic valve in whom a Ross procedure was performed.

Connecting Rigidities of Various Precision Attachments Compared with the Conical Crown Retained Telescope

The purpose of this investigation was to observe the connecting rigidity of various precision attachments and to compare their connecting rigidities with the conical crown retained telescope (CCT). The connecting rigidity of a retainer was assessed using the flexibility test to measure the mesial and distal end displacements. Four precision attachments were analyzed: the dovetail slide attachment beyeler, cylindrical slide attachment, Spang Stabilex and Mini SG. The CCT was used as the control. Although there were many statistically significant differences between the displacements with the various attachments, displacements when vertically loaded were very small: all mesial end displacements were within 3 microm and distal end displacements were 21.4 microm. The largest of the mesial end displacements when horizontally loaded was as large as 44.5 microm (dovetail slide beyeler), while the others were all below 16.5 microm. The same phenomena occurred with the distal end displacements when horizontally loaded: the largest was seen with the dovetail slide beyeler, followed sequentially by the Spang Stabilex, CCT, cylindrical slide, and the Mini SG. The distal displacement with the dovetail slide beyeler was as large as 75.2 microm; those with the others were all below 31.2 microm, with numerous statistically significant differences between the displacements with the various attachments. Thus, connecting rigidities of rigid precision attachments are very similar to CCT, and only the dovetail slide beyeler attachment is too weak to resist horizontal displacement force.

Combined prosthodontic and orthodontic treatment of a patient with a Class III skeletal malocclusion: a clinical report

This clinical report describes a multidisciplinary approach for the treatment of a patient with Angle Class III skeletal malocclusion and decreased occlusal vertical dimension. An overlay removable partial denture (ORPD) was used to reestablish the occlusal vertical dimension (OVD). After the trial and adjustment period, the reduced lower anterior dentofacial height was orthodontically increased and the negative horizontal overlap was corrected. A maxillary precision attachment RPD and a mandibular fixed partial denture and metal ceramic crowns were fabricated to satisfy esthetic and functional requirements.

Distal implants to modify the Kennedy classification of a removable partial denture: a clinical report

Dental implants or precision attachments can be used to resolve the bilateral distal extension removable partial denture (RPD) dilemma. This report describes the fabrication of a mandibular implant-supported chromium-cobalt RPD with a combination of bilateral single molar implants and metal ceramic crowns using the principles of the channel-shoulder-pin system. The maxillary arch was restored with splinted metal crowns and a conventional RPD retained by extracoronal precision attachments.

An impression technique for optimal positioning of precision attachments for removable partial dentures

Precision attachments such as the Dalbo attachment (Cendres & Métaux SA, Biel-Bienne, Switzerland) soldered to a post and core, significantly enhance the retention of removable partial dentures.1 Their use eliminates the need for visible retentive and support components, especially in esthetic areas.2 Optimal positioning of the attachment should be in harmony with the path of insertion of the planned prosthesis.2 An impression technique that facilitates optimal location of the attachment is described.

Stress distribution of abutments and base displacement with precision attachment- and telescopic crown-retained removable partial dentures.

Five types of removable partial dentures (two attachment dentures, two telescopic dentures and one clasp denture) were designed. The two attachment dentures were retained by the rigid-precision attachments with or without a stabilizing arm, and the two telescope dentures were retained with cone telescope crowns with or without cross-arch stabilization. The stresses acting on abutment teeth and denture bases and the movements of denture bases were investigated, and the influences of denture design were clarified. The stress acting on a terminal abutment tooth retained by a rigid-precision attachment or cone telescopic crown was larger than that acting on a terminal abutment tooth retained by a clasp. The attachment dentures tended to concentrate more stress at the terminal abutment tooth than did the telescopic dentures. The stress of denture base of an attachment denture and a telescopic denture was less than that of a clasp denture. There was no difference between the stresses of attachment and telescopic dentures. The displacement of the denture base tended to be less when the denture was designed with a rigid connection for the retainer and with cross-arch stabilization.

Immediate Loading

I should begin by differentiating this concept from Immediate Placement (non-exact osteotomy with bone regenerative techniques) in conjunction with Immediate Loading. Immediate load as discussed in this essay refers to an interim or temporary restoration on a “just placed” implant fixture. While attending a formal oral implantology fellowship at the University of Pittsburgh in 1986, we were taught to understand and appreciate the efforts and accomplishments of those pioneers dedicated to the desire to help those patients whom conventional dental education and techniques could not satisfy. We hear how history has a way of repeating itself (that’s why it should be studied) and that few ideas are actually new. This is one of those ideas. Turning a two-stage protocol, as we understand it, into a one-stage technique is just turning the clock back from 1982 to 1972 and presenting this idea in 2002! This history, along with the evolution of implant materials and better bone physiology understanding, bring the need for, and practicality of, immediate loading to the forefront. The desire and demand for implant restorations have grown tremendously. Single-tooth restorative dentistry, often achieved via dental implants, is more predictable and successful than complex and advanced restorative dentistry requiring multiple abutments, pontics, and precision attachments. With the concept of interceptive prosthodontics, immediate load protocol is our most current challenge. This challenge must be approached with a scientific basis and understanding to be resolved. Applied research as it relates to a predictable outcome for our patients must be a science that applies to all clinicians, not a skill that can be mastered by only a few. We must separate our desire to help our patients from the actual bone physiology of healing. The big question is whether we are able to handle any prosthetic issues during healing (ie, occlusion, esthetics, function, etc.) without compromising the bone’s ability to stabilize the implant fixture as it osseointegrates. For predictable clinical dentistry we must calculate risks and minimize errors. In private practice communities, who will be responsible for the added failures? If we accept a 5 to 10% failure rate with immediate implant loading, when we are accustomed to a 1% failure rate with conventional two-stage implant protocol, then who explains and absorbs the costs of money and time? Private dental practice is not a research situation that is grant-based or state subsidized, but is patient-based relying on the judgment and expertise of the dental implant team. Who will place, reline, and adjust the interim prosthesis at the time of surgery before closure? By immediately loading the implant, are we evolving away from the team concept to a one-stop shop concept? Are we potentially disillusioning patients by presenting a possible “immediate gratification” that may prove to diminish the long-term quality of the treatment outcome? Immediate load concepts are further limited in implant overdenture prosthetics as the support bar is either prefabricated or designed by connecting the implants over the existing ridge. With a two-stage approach, the implant bar is created to develop a “new ridge” that can support the intended tooth position. With this approach, the implant bar can be fabricated in the proper buccolingual, anterioposterior, and vertical location to properly support the prosthesis. Prosthetic techniques used with immediate loading may give patients “teeth in a day,” but isn’t the profession more directed toward benefits for a lifetime? Patients are paying higher fees for less time and receiving less than desired results. The philosophy of a two-stage dental implant protocol has provided a predictable, scientifically based method for patient care and brought implant dentistry out of the “dark ages.” It has provided the opportunity to change the philosophy of restorative dentistry. It has given patients and practitioners new hope with excellent results. Studies have shown that primary bone stabilization of the implant fixture may occur 2 months after initial placement. I present that as a first step toward reaching immediate loading. We should first look at indexing of the implant at the time of first stage surgery, then place a provisional restoration at uncovery 2 months later. I believe we must be comfortable with this approach initially, doing it routinely and achieving excellent results. This technique allows everyone in the implant team to develop their skills, improve their communication, decrease risks, and evaluate their results. Currently, I feel that possible indications for using immediate dental implant loading (with associated risks) are as follows: Teeth receiving minimal load (eg, maxillary lateral incisors, teeth with no opposing occlusion, etc.). The ability to temporarily splint the provisional implant restoration to adjacent teeth or integrated implants. Dense Type II bone. I look forward to and believe that Immediate Loading will continue to evolve and mature and that scientific research will clarify its predictability in our implant treatment plans. ** John P. Davliakos, DMD

Polarized Infrared External Reflection Spectroscopy of a Uniaxial Monolayer at the Air/Water Interface

A theory on polarized infrared external reflection spectroscopy (ERS) of a uniaxial monolayer at the air/water interface was described. Some aspects of this theory, such as the optimal incidence angle, the orientation-frequency correlation, and the surface selection rule were addressed. The most important theme is to obtain the anisotropic complex refractive indexes of the monolayer. A monolayer of F(CF 2 ) 4 -(CH 2 ) 2 2 COOH at the interface of air and the aqueous Cd 2 + subphase was chosen as an example. The Langmuir-Blodgett (LB) technique was applied to deposit the monolayer onto solid substrates. The anisotropic complex refractive indexes were obtained from infrared measurements of the monolayer on the solid substrates. By use of these optical constants, the polarized ERS spectrum of the monolayer on the aqueous Cd 2 + subphase was simulated and compared to the experimental one. The comparison sorted out artifacts associated with the LB transfer process and unambiguously predicted the molecular orientation at the air/water interface. It is concluded that at the optimal incidence angle of 80°, the p-polarized ERS method can achieve an accuracy of ′1° in locating the average orientation angle of a transition dipole moment (TDM). This case happens when the TDM is oriented near the vanishing angle. The TDM orientation angle of the CH 2 antisymmetric stretching vibration along the -(CH 2 ) 2 2 - chain was determined to be 56° ′ 1° on the aqueous Cd 2 + subphase at 283 K and 20 mN/m. On the other hand, the best accuracy of the s-polarized ERS method can achieve is ′2°. The validity of the polarized ERS theory was checked by comparing the present orientation angles with previous ones obtained from polarization-modulated ERS measurements. Finally, a high precision attachment for the water surface measurement was employed, guaranteeing the quantitative aspect of the ERS spectra.

Custom precision attachment housings for removable partial dentures

<h2>Abstract</h2> Limited space for extracoronal attachments is a serious complication in the design and fabrication of a precision attachment removable partial denture. A custom metal-ceramic housing joined to the partial framework with laser welding offers strength and improved esthetics while requiring minimal space. This article presents the technical aspects of custom housing construction. <b>(J Prosthet Dent 2002;88:100-2.)</b>

Custom precision attachment housings for removable partial dentures

Limited space for extracoronal attachments is a serious complication in the design and fabrication of a precision attachment removable partial denture. A custom metal-ceramic housing joined to the partial framework with laser welding offers strength and improved esthetics while requiring minimal space. This article presents the technical aspects of custom housing construction. (J Prosthet Dent 2002;88:100-2.)