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At least 1,531 records · Page 85Linked to original sources
PubMed2004

Indirect bonding: a comprehensive review of the advantages.

Interest in indirect bonding has grown rapidly worldwide and continues to expand. Although the concept began as a specific technique, the literature has shown a number of approaches to the indirect placement of brackets, all of which outline the advantages of indirect bonding. This summary reviews the advantages of indirect bonding in terms of: (1) clinical advantages, (2) technical advantages, and (3) ergonomics and efficiencies.

Dental Bonding↗
PubMed2006

Influence of premolar extractions on tooth size discrepancy. Part two: Analysis of Bolton values.

The purpose of this study is to investigate whether the extraction of four premolars as a requirement of orthodontic therapy is a factor in the creation of tooth size discrepancies (TSD) (Bolton value (BV)), and to determine whether any tooth extraction combinations create more severe discrepancies comparing our result with the results from analogical studies. Hypothetical tooth extractions were performed in all cases by the following combinations: all first premolars, all second premolars, upper first and lower second premolars, and upper second and lower first premolars, estimating extraction influence on TSD frequency and size. 148 pretreatment dental casts were examined. It has been determined that in normal TBI group the smallest discrepancies were created after the second (1.087 mm) and fourth types of combinations have been chosen (1.174 mm). In a low TBI group, the smallest discrepancies occur after first (1.544 mm) and third (1.568 mm) types of removal. In high TBI group the smallest discrepancies appear after type two (3.379 mm) and type four (3.586 mm) have been chosen.

Bicuspid↗
PubMed2006

The effect of disinfection on irreversible hydrocolloid and type III gypsum casts.

Under standardised conditions, 80 impressions were made of a ruled stainless steel die (ISO Specification 1563) using irreversible hydrocolloid (alginate). The alginates were subsequently treated with 3 commercially available disinfectants, Perform-ID, ImpressiVand Dimenol and poured with type III gypsum. The alginates were evaluated for surface detail reproduction and the gypsum for surface detail reproduction and hardness. Disinfection with Perform ID significantly affected the surface detail reproduction of alginate while Dimenol and ImpressiV did not. Perform ID and Dimenol both significantly affect the hardness of poured type III gypsum casts while ImpressiV did not.

Alginates↗
PubMed2006

Indirect bonding technique.

Accurate bracket placement is the key for the successful treatment of an orthodontic case. With indirect bonding, not only is the bracket placement more accurate but this technique also significantly reduces chairtime. In this article, the author explains use of thermal glue in an indirect bonding technique. In cases of constricted arches, a modified rapid maxillary expander can be used along with indirect bonding to reduce overall treatment time.

Adolescent↗
PubMedDate not supplied

[The physical modelling of the process of dental material wear].

The regularities of 12X18H9T corrosion-resistant steel wear were studied in relation to denture movement rate, pressure, and artificial environment characteristics. The factors responsible for steel wear were found to be contact pressure magnitude, the interacting crowns relative movement rate and acceleration, and salivary composition.

Corrosion↗
PubMed1991

The use and fabrication of a self-retaining surgical guide for controlled implant placement: a technical note.

A technique for using a surgical guide construction with a self-retaining feature, which has proven to be a significant improvement for stage 1 surgical procedures, is described. This design is more convenient to use than previously described occlusal extension splints. It maintains the concepts for ideal fixture placement that have proven so valuable in creating both a functionally and esthetically uncompromised prosthesis supported by implants.

Dental Implantation, Endosseous↗
PubMed1991

Predictable seating of the single-unit cast restoration.

Prior to cementation, a cast restoration must be clinically evaluated in a number of critical areas. The proximal contacts and internal surface of the casting, as well as centric and excursive occlusion, require assessment and generally require adjustment before cementation. The time necessary to accomplish these adjustments is not predictable. A technique is presented that permits the majority of these adjustments to be completed in the laboratory, thus minimizing the clinical time required to seat the casting.

Crowns↗
PubMedDate not supplied

[Ergonomy--dentistry--biomechanics].

In this paper the authors present with scientifically--critically looking, ergonomicas--in interdisciplinary group of applied sciences, show the outstanding possibilities of complete analysis and improvement of "man--machine--environment system". With a scientific approach and use of the latest principles of modern ergonomics, the term of dental ergonomics is introduced in dental medicine. It particularly refers to the creation of different models of dental equipment, instruments and working areas, as well as to the investigation of the harmful factors and the effects of working environment on the dentist's health, especially, on the locomotor system which is mostly affected within the "dentist/patient/--equipment--environment system". In conclusion the authors pointed to the fact that there are still so many uninvestigated questions and problems related to dental ergonomics.

Dental Equipment↗
PubMed1990

[The study on surface porosity of die stone. Influence of vinyl polysiloxane impression materials].

In this study, the authors have attempted to discover optimum conditions for eliminating all porosity, except what is caused by manual error, in the surfaces of Die Stone. Five vinyl-porisiloxane impression materials, two other kinds rubber impression materials, and two kinds of die materials were used. Die materials were poured at intervals of 0, 15, 30, 60, and 120 minutes after the impression had been removed. Cast-surface porosity was measured by means of SPICCA II. Results 1. Practically surface porosities were not scarcely observed in casts made from any of the impression materials except vinyl silicone rubber. Among the five vinyl-polysiloxane impression materials, Hydrophilic Exaflex produced the least porosity. 2. Porosity in casts made with Provil tended to decrease definitely as pouring time progressed. This tendency occurred with no other materials. 3. When the die material was mixed at a low water-powder ratio, cast-surface porosity was reduced in the case of all materials except President. 4. Concentration of hydrogen gas, which was released from all vinyl-polysiloxane impression materials, decreased with the passing of time. 5. In the case of Provil, a correlation existed between hydrogen-gas concentration and the degree of cast-surface porosity. But no similar correlation was observed in the case of any other vinyl-polysiloxane impression materials.

Dental Impression Materials↗
PubMed1990

[The physical properties of silicone impression materials with hydrophilicity and hydrophobicity. Wetting, water absorption, surface structure of dental stone and dimensional change on stone dies].

In order to compare the physical properties of the silicone impression materials with regard to their hydrophilicity and hydrophobicity, wetting and water absorption, the surface structure and dimensional changes of stone dies were investigated. The evaluation of wetting was performed on one kind of addition-type material with hydrophilicity, five kinds of addition-type materials with hydrophobicity and one kind of condensation-type silicone impression material. One kind of addition-type silicone impression material with hydrophilicity and hydrophobicity was used in other research. Wetting was assessed by measuring the contact angle between water and the impression materials. Water absorption was assessed by the change in weight of the impression materials after immersion in water. The surface structure of the dental stone was observed by SEM. The dimensional changes of stone dies were measured by means of an apparatus designed in this department. The results were as follows: 1. Wetting: The addition-type impression material with hydrophilicity had a 51.4 +/- 1.3 degree contact angle, and other impression materials varied from 84.6 +/- 6.1 degrees to 97.7 +/- 4.4 degrees. 2. Water absorption: The amount of water absorption of the hydrophilic type was greater than that of the hydrophobic type. 3. The surface structure of dental stone: In the case of Vermix stone, which was poured into water-immersed hydrophilic type material, the stone crystals became large, but Fujirock showed no change. 4. The dimensional change on stone dies: No difference was apparent between the hydrophilic type and the hydrophobicity type. 5. Hydrophilicity may affect the surface structure of the dental stone slightly but this is possible within the permissible clinical limits.

Absorption↗
PubMedDate not supplied

Effect of reheating on the accuracy of polysulfide impressions.

Polysulfide impressions were made at 37 degrees C in two cylindrical trays of a truncated cone-shaped chromium-steel die. One tray size was used to obtain impressions with 1 mm thickness from tray to the gingival margin of the preparation, while the second tray permitted a thickness of 4 mm. Stone dies were made from impressions after (1) cooling to 22 degrees C for 10 min or (2) cooling to 22 degrees C for 10 min and reheating to 37 degrees C for 30 min. Results revealed that reheating impressions to mouth temperature before pouring the dies improved their accuracy.

Dental Impression Materials↗