A resin-modified glass ionomer restorative: three-year clinical results

Resin modified glass ionomer (RMGI) restorative materials have gained popularity in recent years. Their use is most often indicated in Class III and Class V cavities in adults and in numerous applications in children. This popularity in use has taken place in the absence of scientific knowledge of the RMGI materials. Lacking are adequate clinical trials to validate the proposed indications. The purpose of this study was to examine a representative RMGI in cervical abrasions and root caries in adults. Patients were recalled up to three years to evaluate standard clinical criteria. Results found the RMGI to be inferior to conventional composite resin in similar applications. The most noted deficiencies were in color stability and anatomic form, or wear of the RMGI. The results of this prospective clinical trial would suggest a limited longevity for RMGI compared to traditional restorative materials. This study also reinforces the need for evidence of clinical performance prior to making decisions regarding material selections.

Fixed prostheses in the treatment of tooth wear

The restorative implications of tooth wear are often complicated by the age of the patient, the destructive nature and aesthetic compromise of conventional fixed restorations and the lack of inter-occlusal space. This paper focuses on the fixed prosthetic treatment options for such patients and the utilisation of fixed restorations to create inter-occlusal space.

Restorative dental treatments of abraded canine teeth in a Sumatran tiger (Panthera tigris sumatrae)

A Sumatran tiger had developed severely abraded canine teeth by biting on cage-bars. This resulted in weakening and marked sensitivity of the teeth. Indications for, techniques of and complications of restorative dental treatments are described. The outcome of different restorative dental treatments indicates that endodontic treatment should be carried out first if the fracture of a weakened tooth is anticipated. To improve retention, the acid-etch technique is preferred in combination with macroretentive preparations. In this case, amalgam was used successfully in combination with composite resin to restore function to a canine tooth with a large distal defect.

Management of the short clinical crown by indirect restorations

This paper describes the acute and chronic causes of short clinical crowns and their management. Fracture or trauma are common causes of acute failures whilst toothwear is the most common cause for chronic causes. There are many methods of restoring teeth using conventional indirect techniques, which may alter the existing occlusal vertical dimension (such as orthodontic Dahl appliances), or conserving the vertical dimension by increasing the length of the teeth. These methods are described and illustrated to assist the practitioner choose the most appropriate restoration.

The role of removable prostheses and implants in the restoration of the worn dentition

A variety of removable prostheses is available to restore the dentition which exhibits wear and extensive loss of teeth from the arch. Such treatment may be either interceptive or transitional in order to stabilise the occlusion or definitive as part of rehabilitation. Tooth surface loss may necessitate crowning with the provision of conventional removable partial dentures or decoronation and the use of overdentures. Extensive loading generated by parafunction is often considered to risk the failure of restorations stabilised by implants and so may contra-indicate treatment. Screening out unsuitable cases appears to result in few incidents of implant failure and new designs may further reduce the risk.

Esthetic recontouring. A team approach

The presence of irregular incisal edges, a worn or abraded dentition, and imbalances in tooth morphology compromise a harmonious esthetic smile. A team approach is indicated after extensive orthodontic or prosthetic treatment to reach a final cosmetic result. Intentional changes in tooth form by recontouring provide an improved outcome. This article presents the components of a harmonious smile, evaluation, guidelines and a stepwise approach for the esthetic recontouring of anterior teeth. Two cases illustrate the effects that are achieved with this methodology.

The prevalence, etiology and management of tooth wear in the United Kingdom

STATEMENT OF PROBLEM

Recent epidemiologic evidence suggests that tooth wear is now a significant problem in both children and adults. There is growing evidence that a major cause of severe wear in patients is regurgitation erosion due to a variety of factors including gastroesophageal reflux disease.

PURPOSE

The purpose of this article is to discuss the prevalence of tooth wear in the United Kingdom. Emphasis in management should be on accurate diagnosis, and in some patients, long-term monitoring before embarking on any irreversible, interventive treatment. Even when treatment is necessary, a period of monitoring is helpful to assess the rate of progress of the wear, the effectiveness of preventive measures, and therefore the extent of the treatment necessary.

The clinical evolution of the 'Dahl Principle'

The restorative management of patients with localised tooth wear is a major challenge to the dental profession. There is rarely adequate interocclusal space available to place restorations without the need for extensive tooth preparation or the involvement of many unaffected teeth. In 1975, a method was described which created interocclusal space by the use of a partial coverage appliance made of cobalt chromium alloy. The technique reduced the need for more invasive palatal reduction. This paper, with the aid of clinical case examples, highlights the development and evolution of the original removable appliance. However, there remains a need for further clinical studies to evaluate fully these techniques.

Guidelines for the restoration of Class V lesions

Approximately 18 percent of all permanent teeth have Class V lesions. In addition, the prolonged retention of teeth in an increasingly older population is expected to increase the prevalence of Class V lesions. Much has been written about the merits of various techniques for restoring such lesions, but little information is available comparing and contrasting all the material and procedural options available to the general dentist. Etiologies, indications for treatment, and restorative materials are discussed to provide guidance in planning treatment. A diagnostic decision tree is proposed for this dynamic area of restorative dentistry.

In vivo changes in roughness of resin-modified glass ionomer materials

OBJECTIVES

The clinical changes in roughness of resin-modified glass ionomer materials is relatively unknown. This study examined the in vivo wear of these materials using surface roughness as an indicator of wear patterns.

METHODS

Ten patients with four cervical abrasion lesions each were selected. The four cavities in each patient were restored with Fuji II LC (GC Corp., Japan), Vitremer (3M Dental, USA), Photac-Fil (ESPE, Germany) and Fuji Cap II (GC Corp., Japan). After light-curing, the restorations were polished and left uncoated. Silicone impressions were made of the surface of each restoration after polishing, and then at 3 monthly intervals up to 24 mon after restoration placement. Gold-coated resin replicas were made from the impressions for surface wear evaluation. Quantitative assessment of wear was performed by measuring surface roughness with a confocal microscope for topographical reconstruction of the specimen surface. The effect of material at each time period was analyzed using the Kruskal-Wallis test with exact non-parametric inference. Rugosity, as determined by the center line average, was determined by image analysis. SEM images of the same surfaces provided the qualitative analysis.

RESULTS

All restorations showed a cyclic distribution of rugosity with time as demonstrated by lowess plots. There were significant differences between materials at 6, 9 and 18 mon. The rugosity curves appeared to converge at 24 mon.

SIGNIFICANCE

It was concluded that the in vivo surface changes in roughness of resin-modified glass ionomer materials is cyclic in nature over the first 2 y.

[Tooth wear. Classification and terminology]

Tooth wear rarely occurs as a result of one factor alone. Non-carious loss of tooth tissue can be subdivided into attrition, demastication, abrasion, fractionation, and erosion. Clinically, the tooth tissue loss may result from any combination of these types of wear. The first essential principle in the management of tooth wear is, as far as possible, to remove the cause. Secondly, restoration may be indicated.

Clinical evaluation of hybrid ionomer restoratives in Class V abrasion lesions: two-year results

Eighty Class V abrasion cavities were selected, and 20 cavities were restored with one of three resin-modified glass-ionomer materials (Fuji II LC, Photac-Fil, and Vitremer) or a polyacid-modified resin composite (Dyract). The restorations were clinically evaluated after 1 and 2 years with the US Public Health Service criteria. The results revealed a statistically significant difference in the percentage of restorations rated Alfa for color match at 2 years. No statistically significant difference was found in the percentage of alfa rating for anatomic form. Restorations of all materials showed some marginal discrepancies that were not statistically significant.

Guidelines for managing the orthodontic-restorative patient

Occasionally, patients require restorative treatment during or after orthodontic therapy. Patients with worn or abraded teeth, peg-shaped lateral incisors, fractured teeth, multiple edentulous spaces, or other restorative needs may require tooth positioning that is slightly different from a nonrestored, nonabraded, completely dentulous adolescent. Generally, orthodontists are not accustomed to dealing with patients who require restorative intervention. Should the objectives of orthodontic treatment differ for the restorative patient compared with the nonrestorative patient? How should the teeth be positioned during orthodontic therapy to facilitate specific restorations? Should teeth be restored before, during, or perhaps after orthodontics? The answers to these and other important questions are vital to the successful treatment of some orthodontic patients. This article will provide a series of eight guidelines to help the interdisciplinary team manage treatment for the orthodontic-restorative patient.

Treatment of localized anterior toothwear with composite restorations at an increased occlusal vertical dimension

Patients may present with localized anterior toothwear, complaining of poor appearance or sensitivity, or both. Restoration of these teeth continues to cause problems, especially if interocclusal space has been lost. Conventional treatment to satisfy the patient's aesthetic and functional demands is time consuming and requires careful maintenance. This paper describes the use of chairside composite resin restorations in the treatment of localized anterior toothwear. Interoccusal space is provided by placing the restorations at an increased vertical dimension of occlusion. It enables the presenting complaint to be resolved while restoring structure, function and appearance.

[The principles of designing stump pin inserts in pathological tooth abrasion]

A total of 278 patients aged 40 to 67 with pathological abrasion of hard dental tissues were treated. Decreased occlusion height was diagnosed in 152 (54.67%) of these. In 146 patients abutment teeth under permanent dentures were fixed with cast stump pin insertions. Complications occurred in 9.6% cases: perforation of the wall of the root canal (1.14%), failure of cementing (3.98%), fracture of the root (1.14%), breaking of a fragment of the root at the neck of the tooth (2.84%), and inflammations of the marginal periodontium (0.57%). In order to prevent these complications and improve the fixation of cast stump pin insertion, we used our modifications of cast stump pin insertions (n = 394) for anterior and lateral teeth. The incidence of complications decreased more than 5 times. Follow-up of 2 to 8 years showed 1.78% of complications.

[Periodontal tissue status in shortening of the interalveolar distance]

A total of 186 patients aged 40 to 65 with short interalveolar distance were treated. 65.5% of them developed pathological changes in the marginal periodontal tissues (inflammation, periodontal and osseous pouches, resorption of bone tissue of the maxillary alveolar process). Patients with involvement of the marginal periodontal tissue were treated by therapeutic, surgical, and orthodontic methods. Good results were attained in 95.1% of patients.

[Occlusion-building with tooth-colored restoration materials]

Severe localized or generalized tooth wear will result in loss of vertical dimension. Rehabilitation of the dimensional height is often required. A causal approach is the choice of preference to prevent progression of destructive processes. However, the etiology of pathological wear is not yet clarified, so reversible and non-destructive tooth saving restorative procedures are essential. For adjustment and stabilization of the occlusion of CMD problems the philosophy and treatment approach are similar. Tooth coloured adhesive restorations can be fabricated in different manners, directly and indirectly. In this article treatment objectives for occlusal rehabilitation are described and two cases presented where tooth coloured restorations are used.

Three-year clinical effectiveness of four total-etch dentinal adhesive systems in cervical lesions

A 3-year follow-up clinical trial of two experimental Bayer total-etch adhesive systems and two commercial total-etch systems. Clearfil Liner Bond System and Scotchbond Multi-Purpose, was conducted to evaluate their clinical effectiveness in Class V cervical lesions. Four hundred twenty abrasion-erosion lesions were restored randomly using the four adhesive systems. There were two experimental cavity designs, in which the adjacent enamel margins either were or were not beveled and acid etched. Clearfil Liner Bond System and Scotchbond Multi-Purpose demonstrated high retention rates in both types of cavity design at 3 years. The two experimental Bayer systems scored much lower retention rates in both cavity designs at 3 years. None of the systems guaranteed margins free of microleakage for a long time. At 3 years, superficial, localized marginal discolorations were observed, the least for Clearfil Liner Bond System, followed by Scotchbond Multi-Purpose and the two experimental systems. Small marginal defects were recorded at the cervical dentin and the incisal enamel margin. Retention of Clearfil Liner Bond and Scotchbond Multi-Purpose appears to be clearly improved over earlier systems, but marginal sealing remains problematic. The two Bayer systems were found to be clinically unreliable.

Clinical performance of two dentine adhesives: 2-year results

Scotchbond MP and ART Bond were used without intentional enamel etching to bond a total of 43 resin composite restorations in Class V 'abrasion/ erosion' lesions. The cumulative loss rates after 6 months, 1 year, and 2 years, respectively, were Scotchbond MP: 9, 14, 27 per cent; and ART Bond: 0, 5, 5 per cent. These data were not compared because each material was used on different patients. The results support the higher bond strength to dentine in the laboratory of Scotchbond MP compared with its predecessor Scotchbond 2. There was a slight but clinically insignificant amount of enamel marginal staining for both products after 2 years, confirming the necessity to etch the enamel for effective marginal sealing.