摘要:

In this retrospective study 516 teeth restored with a cast post and core build‐up were followed from 1970 till 1990. The data was derived from the dental records of 283 dental clinic patients treated by senior students. The survival rate was found to be 82% after 10 years for post and cores in the anterior region. The most frequent failure characteristic was recementation (46%), followed by rerestoration (32%). The solitary provisions in posterior teeth showed a relative high survival rate, compared with other tooth‐types and locati

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01631.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Most reports of the prevalence and severity of tooth wear in contemporary Western populations claim that advanced wear is uncommon by comparison with certain non‐Western populations. Differing methods of wear evaluation in the various studies, however, preclude accurate comparisons from being made. This study records mean total and segmental wear indices obtained from the casts of a selected Swedish patient population sample, and age‐ and sex‐matched Saudi high‐wear and random samples. The wear experience of the Saudi random sample compared favourably with that of the Swedish selected one, while the wear of the Saudi high‐wear sample was significantly higher than that of the Swedish sample (P<0.01). The findings from a questionnaire revealed certain significant correlations between aetiological factors and wear, most notably, the relatively greater presence of bruxism (P<0.01), absence of biting habits and minimal cola consumption (P<0.01) in the Swedish sample. Harsh environmental and climatic conditions probably account for the Saudi experience of

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01632.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The long‐term effects were studied of a full arch maxillary plane occlusal splint on chronic signs and symptoms of craniomandibular disorders (CMD) in 31 patients with nocturnal bruxism. The results revealed that the score and intensity of signs and symptoms in this type of patient fluctuate from day to day and even within a single day. In spite of continuation of nocturnal bruxism, the symptoms of CMD were cured or improved with the long‐term use of the occlusal splint. However, in general, the symptoms recurred after discontinuation of splint therapy. The therapeutic mechanisms of the splint during sleep are discus

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01633.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Effects of materials and techniques on the accuracy of models used to make indirect restorations was measured using a 4‐unit posterior model containing a MOD and full crown preparation. Improved stone and fast setting epoxy dies backed with either improved stone or a thermoplastic hot melt stone were made from single‐viscosity addition silicone impressions. Technique variations included heating or not heating the impression, cooling and pouring dies and placement of the hot melt stone on set or unset epoxy. The dimensions of the MOD (L, W, H) and of the crown (W, H) dies were measured at 1 and 24 h. No clinically significant changes occurred between 1 and 24 h. The stone control reproduced the dimensions of the master die best, and models made by pouring epoxy into the impression followed by immediate pouring of the hot melt stone gave the poorest reproduction. Other variations in technique using epoxy for the anatomical portion gave no practical differences in accuracy. Of the epoxy dies, those prepared from a previously heated impression with hot melt poured after the epoxy set had the best values; however, epoxy dies were smaller than stone dies. The fast set epoxy was noteworthy for rapid processing and sharp detail, however, negative changes for W and H of the crown and H and L of the MOD showed that a die spacer would be essential in the preparation of indirect restorati

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01634.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Salivary flow rates were monitored in two patients, treated with acupuncture for post‐radiotherapy xerostomia. The flow rates improved after acupuncture and the effect persisted during the 2‐year observation per

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01635.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Post‐operative pain has been associated with composite polymerization shrinkage. This study aimed to quantify the cuspal deflection resulting from the initial shrinkage and the subsequent hygroscopic expansion of a standard posterior composite resin.Thirty hydrated permanent molars were marked on the buccal and lingual cusp tips. Standardized conventional Class II preparations were made and restorations with composite resin were placed and: (A) polymerized as one complete unit; (B) polymerized in gingivo‐occlusal increments; (C) polymerized in buccolingual increments. Ten untreated teeth were marked and acted as controls. All specimens were placed in water. Pre‐operative, post‐operative and 6‐month photographs were projected on a digitizer pad and measured by two independent investigators. The mean cuspal deflection (μm) immediately post‐operatively and 6 months respectively, was: (A) 22.4, 8.7; (B) 12.4, 5.3; (C) 9.8, 3.0. The percentage of natural tooth dimensional recovery, following hygroscopic expansion was: (A) 97.5%; (B) 98.6%; (C) 99.4%. Buccolingual incremental polymerization led to significantly less initial cuspal deflection and the most cuspal recovery after hygroscopic expansion. The technique of resin placement therefore may provide a decrease in post‐operati

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01636.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

A radiographical study has been performed to evaluate the movement of the disc posterior band over the condylar head during mandibular opening. Six formal free embalmed subjects were selected as ‘normal’. Micro stainless steel balls were used as landmarks both into the bone and into the disc for X‐ray identification. The data was processed at each phase of movement in selected planes. The true coordinates of each disc landmark gave the potential to calculate the linear length of their path and any distance change between them. It can be concluded that there is a 5% width reduction during the opening movement and it also suggests strongly that a fair amount of translation movement between the disc and the condyle occurs in the lower compar

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01637.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The bases of occlusal rims and trial dentures may sorb water during disinfection procedures, adjustment in the mouth and rinsing and cooling under running water. Such sorped water may adversely affect the properties of the baseplate materials. The room temperature water sorption of sheets of grey and pink shellac and cold cure acrylic resin was determined over 10 weeks by weighing. The Wallace surface hardness, linear dimension and transverse strength were also measured each week. Specimens were reweighed each week as they dried at room temperature. At the conclusion of the tests, the materials showed a change after soaking in weight, hardness, linear dimension and transverse strength, and change after drying relative to original mass for grey shellac of +1.5%, ‐48%, +0.7%, ‐58%, +0.33%; for pink shellac of +2.0%, ‐56%, +0.9%, ‐65%, +0.4%; and for acrylic resin of +1.2%, +10%, +0.4%, ‐30%, ‐2.1% respectively. The acrylic resin material was thus less affected by water sorption than the grey and pink shella

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01638.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

A new portable system for measuring nocturnal tooth contacts has been devised. This system was suitable for patients to take home and record tooth contacts by themselves. A micro photo sensor using optical fibres was applied to detect tooth contacts. The sensor and the target were accurately fixed to opposed molars, respectively on the same side, with removable metal attachments. Patients were instructed to set the attachment to their tooth each experimental night. In the present study, data was assembled for four or five nights in three subjects who were free of masticatory pain and dysfunction. Each subject showed an individual tooth contact pattern. It is suggested that this new system is useful and convenient for measuring nocturnal tooth contacts.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01639.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

This study was aimed at clarifying the effects of two different silane compounds on the adhesion between the different fibres and acrylic resin. The fibres used as reinforcement in the acrylic resin test specimens were glass, carbon and aramid fibres and the silane treated and untreated versions of each type of the fibres were tested. The fracture resistance of the test specimens were assessed and the fibres were studied by a scanning electron microscope (SEM) to establish the adhesion between the fibres and acrylic resin. The results showed that silanization of glass and aramid fibres enhances the adhesion between the fibres and acrylic resin. The findings were confirmed by the SEM photographs taken. The use of a scanning electron microscope proved to be useful for the investigation of the adhesive properties of the materials used.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1993.tb01640.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY