Evaluation of dentolabial parameters as part of a comprehensive esthetic analysis

Analysis of the facial features and lip movements in relation to teeth, achieved by evaluating the facial, dentolabial, and phonetic parameters, should be the first step in prosthetic rehabilitation. This article focuses on dentolabial analysis, presenting a systematic approach to evaluating the relationship between the teeth and the lips and lower third of the face. The parameters evaluated include tooth exposure, incisal edge position, smile width, labial corridor, interincisal line vs. midline, and occlusal plane vs commissural line. Here two parameters of dentolabial analysis are explored in depth: incisal edge position (with regard to both incisal curve and incisal profile) and orientation of the incisal plane, which is a portion of the occlusal plane. Methods for identifying both parameters are outlined, and their role in the achieving successful esthetic results in prosthetic treatment is discussed.

Increasing occlusal vertical dimension--why, when and how

Cosmetic dentistry has evolved with the advent of more robust porcelain materials and ever-stronger bonding agents. This series of three articles aims to provide a practical overview of what is now possible both functionally and cosmetically from the preparation of a small number of teeth, through a whole smile, to full mouth rehabilitation. A complete diagnosis is the starting point to planning any cosmetic or functional changes. Guidance is given on the techniques used but adequate training must be considered essential before embarking upon modification in occlusal schemes or even minor adjustments in smile design. Understanding vertical dimension and how and when it can be changed has always been a challenging prospect for the general dental practitioner. This article aims to discuss the rationale behind changes in vertical dimension and demonstrate how it can be achieved in general practice assuming adequate hands-on postgraduate training has been completed.

Non carious cervical lesions. A review

Non-carious cervical lesions (NCCL) are characterized by a loss of hard dental tissue near the cement-enamel-junction. Commonly, their shape is like a wedge with the apex pointing inwards. Other times, they appear as regular depressions, like a dome or a cup. Their main characteristic is the presence of hard-mineralized tissue. According to the literature, the prevalence of cervical lesions is 85%, while their incidence is about 18% among permanent teeth. NCCL are currently classified as erosion, abrasion, or abfraction. Their etiology seems to be related to different factors: hexogen and endogen acids, mechanical abrasive action, tooth flexion under axial and non-axial loads. Moreover, it seems that a fundamental role is ascribable to tooth bending phenomena due to the strength components parallel or oblique to the occlusal level, which occur during the normal function as well as during parafunctions. The frequent therapeutic failures are probably due to the same factors causing the onset of the original lesion. Several materials have been proposed to restore NCCL: amalgam (abandoned), glass-ionomer cements, compomers, and composite resins. Early failures of these restorations have often been reported in the literature, probably due to the same factors which originally caused the lesions. Further investigations are required to determine more reliable restorative therapies.

[Bonded porcelain veneers]

Nowadays the porcelain laminate veneer is a frequently prescribed aesthetic restoration for anterior teeth. A substantially reduced tooth preparation is required compared to conventional aesthetic complete crown preparations, in accord with the practice philosophy of minimally invasive dentistry. The long term clinical success of porcelain veneers depends on a careful case selection and diagnostic approach, as well as accurate and appropriate tooth preparation and adhesive bonding procedures. The goal of this paper is to give a reproducible clinical method to the practitioner for the realization of reliable porcelain laminate veneers.

Esthetic noncarious Class V restorations: a case report

When restoring anterior and posterior teeth affected by noncarious cervical lesions, many clinicians overlook the etiologic factors responsible for the lesions' development, resulting in frequent restorative failures. The treatment approach for noncarious cervical lesions must not be based only on restorative procedures since a variety of causative and aggravating factors are related to their formation. This article discusses a treatment protocol and techniques for the restoration of noncarious Class V lesions and presents a clinical case in which esthetic restorations are achieved.

CLINICAL SIGNIFICANCE

Treatment options for noncarious Class V lesions can range from simply eliminating the causative factors of the lesions and regularly monitoring their progression to specific restorative procedures. Resin composites are the best materials for restoring cervical defects owing to their bonding ability, physical properties, and esthetic potential. A straightforward technique for the successful restoration of noncarious Class V lesions is presented.

IPR: intraoral pressure-dependent registration in Cerec application

Cerec 3D software is now able to restore occlusal tooth surfaces safely and reproducibly. With an existing morphology worth adopting and/or by making use of an opposing bite registration, the user can reproduce the central contacts to the opposing jaw with the aid of the correlation mode. However, this assumes that the existing maxillo-mandibular relation is physiological. In prosthetic treatment, it is essential to differentiate between a healthy patient and patients with functional disorders. In the first case, the possibilities of performing an accurate and exact reconstruction of the healthy parameters are given and can be myocentrically controlled and corrected with suitable means. However, in the presence of functional disorders, the pathological situation should not serve at the basis for the reconstruction. Adjustment and, if necessary, stabilization of the function is essential. The following article illustrates by reference to a complex patient case how Cerec restorations can be produced correctly chairside with the aid of the IPR technique even in the case of functional disorders.

Tooth wear as a result of pica

This paper reports a case of tooth surface loss as a result of the eating disorder pica. Background to the condition is discussed and the clinical findings and treatment of the patient outlined. The case illustrates a rare cause of wear which should be considered when patients present with an unusual pattern of tooth surface loss.

Direct restoration of worn maxillary anterior teeth with a combination of composite resin materials: a case report

Tooth loss, alterations on tooth structure, and reduced vertical dimension are known to severely compromise the stomatognathic system. This case report describes the treatment of a patient who presented with an extremely worn maxillary anterior dentition with a loss of posterior support owing to the loss of almost all the posterior teeth, except the mandibular premolars. Provisional removable partial dentures were used to create an optimum maxillomandibular relationship and to provide restorative space prior to the restoration of the remaining teeth. This restoration was accomplished with a combination of layered hybrid and microfilled composite materials, which restored the maxillary anterior teeth to optimum esthetics and function.

Retention of a resin-modified glass ionomer adhesive in non-carious cervical lesions. A 6-year follow-up

OBJECTIVES

The purpose of this study was to evaluate the clinical retention of a new resin-modified glass ionomer cement based adhesive combined with a hybrid resin composite or a poly-acid modified resin composite in non-carious cervical lesions during a 6-year period.

METHODS

The resin-modified glass ionomer adhesive (Fuji Bond LC), was placed in 73 cervical lesions, 36 with a universal hybrid resin composite (Tetric Ceram) and 37 with a poly-acid modified resin composite (Hytac). Fifty-one in lesions with sclerotic dentin and 22 in non-sclerotic ones. Of the sclerotic lesions 38 were slightly roughened with a diamond bur before conditioning. The restorations were evaluated with slightly modified USPHS criteria every six months during a 6-year period.

RESULTS

All except six restorations were evaluated during the 6 years. Twelve (17.9%) were lost, four Tetric Ceram (11.8%) and eight Hytac (24.2%) (p<0.05). Four were found in non-sclerotic lesions (20.0%) and eight in sclerotic lesions (17.0%). The differences between the sclerotic and non-sclerotic and the roughened and non-roughened lesions were not significant.

CONCLUSIONS

The resin-modified glass adhesive showed a superior clinical retention combined with the resin composite material, with an annual failure rate of 2%.

Eighteen-month clinical performance of a self-etching primer in unprepared class V resin restorations

This study evaluated the clinical performance of unprepared Class V resin composites, placed using a self-etching primer and a single-bottle adhesive, over a period of 18 months. Thirty-eight pairs of restorations of Renew hybrid resin composite (BISCO, Inc) were placed using adhesives from the same manufacturer in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 76% of these lesions was considered to be sclerotic. The restorations were placed without abrasion of tooth surfaces, except for cleaning with plain pumice. One of each pair was placed using Tyrian, a self-etching primer and the other was placed using One-Step, a single-bottle adhesive placed after acid etching. Both the etchant and self-etching primer were applied for 20 seconds. The restorations were clinically evaluated at baseline, 6, 12 and 18 months, using modified Ryge/USPHS criteria. For both adhesives, very low retention of 50% to 56% of the restorations was observed over 18 months, leading to the conclusion that tooth surfaces must receive some additional treatment prior to restoration with these adhesives. No statistically significant difference (p=0.75) between the two adhesives was observed in overall performance, and dentinal sclerosis and axial depth did not appear to be important factors in the study.

Reviewing the concept of Dahl

Toothwear may have a multifactorial aetiology but is often localized to the upper anterior teeth. This is normally accompanied by a loss of interocclusal space. This paper aims to outline the management of localized anterior toothwear. It discusses several options available to create space for anterior restoration, with particular reference to the use of the 'Dahl' technique. Dahl described a non-invasive technique to create increased interocclusal space. The increased space eliminates the need for further occlusal reduction during crown preparation which is ideal in the worn dentition. This paper illustrates and describes the clinical applications of Dahl's original technique.

Crown lengthening: basic principles, indications, techniques and clinical case reports

Sometimes, in order to properly restore teeth, surgical intervention in the form of a crown-lengthening procedure is required. Crown lengthening is a periodontal resective procedure, aimed at removing supporting periodontal structures to gain sound tooth structure above the alveolar crest level. Periodontal health is of paramount importance for all teeth, both sound and restored. For the restorative dentist to utilize crown lengthening, it is important to understand the concept of biologic width, indications, techniques and other principles. This article reviews these basic concepts of clinical crown lengthening and presents four clinical cases utilizing crown lengthening as an integral part of treatments, to restore teeth and their surrounding tissues to health.

Enamel mineralization by calcium-containing-bicarbonate toothpastes: assessment by various techniques

Surface defects such as scratching, acidic erosion, and natural dimpling of the tooth enamel can significantly affect its cosmetic appearance. There are many analytical techniques that can be used to view the surface of enamel and to assess the effect of surface treatments. Light microscopy, scanning electron microscopy (SEM), profilometry, and atomic force microscopy (AFM) can usefully be applied to viewing mineral surfaces and obtaining information about surface morphology and smoothness. Energy-dispersive x-ray fluorescence and other surface-ionizing techniques can give information about surface chemistry. Microhardness instrumentation can be used to determine surface hardness, while gloss meters and reflectometry can provide measurements of gloss and whiteness. In this study, four sets of in vitro experiments were performed, which illustrate the value of three of these techniques. Specially formulated calcium-containing toothpastes, designed to fill in surface defects in tooth enamel, were evaluated in four experiments for their ability to effect cosmetic improvements in etched tooth enamel: (1) two calcium-containing, sodium-bicarbonate-based toothpaste formulations were shown by SEM to smooth tooth enamel without introducing new scratches. In contrast, a commercial whitening toothpaste removed similar scratches but also created new ones; (2) calcium-containing dentifrices were shown by SEM and hardness measurements to put mineral onto the surface of enamel and to harden it. The effects of uneven dispensing of the two-phase, bicarbonate-based, calcium-containing formulation were shown to be small; (3) a number of different calcium-containing toothpastes were shown by SEM to deliver mineral onto the etched enamel surfaces, whereas a conventional fluoride toothpaste did not; and (4) AFM was used to follow the smoothing of an etched enamel surface after serial treatments with a calcium-containing, bicarbonate-based toothpaste. After 15 in vitro cycles, surface roughness was reduced by more than 50% and peak height was reduced by about two thirds. The results illustrate the effectiveness of the three analytical techniques and show that the calcium-containing toothpastes can deposit mineral into enamel surface deformities under a wide variety of conditions and from a wide variety of formulas.

Intraoral evaluation of mineralization of cosmetic defects by a toothpaste containing calcium, fluoride, and sodium bicarbonate

New dual-phase fluoride toothpastes that contain soluble calcium, phosphate, and baking soda have recently been introduced into the market. These toothpastes are designed to fill in small surface defects in tooth enamel and thereby enhance tooth esthetics such as gloss. This two-part study was designed to assess these superficial mineralizing effects from using one of these products compared with an experimental calcium-containing, bicarbonate-free formulation and a conventional fluoride toothpaste using an intraoral model. Enamel specimens with 4 types of defects were mounted into an intraoral appliance and placed in the mouths of volunteers for 1 month. The four types of defects were whitening toothpaste abrasion, coarse abrasion, natural dimpling, and acid etching. Before and after intraoral exposure, scanning electron microscope photographs of the specimens were made. The surface microhardness of the acid-etched specimens also was determined. The volunteers brushed their specimens twice daily with one of three randomly assigned toothpastes. The toothpastes were a two-phase, calcium-containing, bicarbonate-based toothpaste; an experimental, two-phase, calcium-containing, bicarbonate-free toothpaste; and a conventional toothpaste. Only the calcium-containing toothpastes showed unequivocal signs of mineral deposition into surface defects, leading to smoothing of the enamel. All three products significantly increased the hardness of the etched enamel, presumably because of fluoride. However, only the two calcium-containing toothpastes gave significantly greater hardness increases than the conventional toothpaste; the specimens treated with a conventional toothpaste were indistinguishable from those treated with saliva.

A randomized, controlled trial evaluating the three-year clinical effectiveness of two etch & rinse adhesives in cervical lesions

A three-year randomized, controlled prospective study evaluated the clinical performance of two three-step etch & rinse adhesives (OptiBond FL, Kerr: O-FL; PermaQuick, Ultradent: PMQ) in Class V cervical erosion-abrasion lesions. The latter adhesive was also tested with two restorative composites with contrasting stiffness in order to evaluate the effect composite stiffness might have on the clinical longevity of cervical restorations. A total of 150 lesions were randomly restored in pairs of the three adhesive/composite combinations (PMQ combined with Amelogen Hybrid: PMQ/A-Hy, Ultradent; PMQ combined with Amelogen Microfill: PMQ/A-Mi, Ultradent; O-FL combined with Prodigy: O-FLJPro, Kerr) per patient and evaluated at baseline, after six months, one year, two years and three years of clinical service. After three years, the retention rate was 100% for O-FL/Pro and 98% for both PMQ/A-Hy and PMQ/A-Mi, thereby, satisfying the "full acceptance" guidelines specified by the American Dental Association. A pairwise comparison showed no significant difference in adhesive performance between restorations made using the microfilled and hybrid composite for any evaluation criteria (p>0.05).

[Clinical using and observation of occlusion splint of RPD]

PURPOSE

This article describes the design and restoration for 180 cases diagnosed with dentition defect accompanied with medium to severe abrasion and attrition. The purpose of this study is to discuss the rehabilitation of vertical dimension, the balance of occlusion and the whole occlusion system.

METHODS

Before clinical preparation of the 180 clinical cases, diagnostic casts were made. Entire restoration treatment plan was adopted to make removable partial dentures with full crown restorations along with occlusion splints. The clinical effect were evaluated at 2nd week, 4th week and 9th week.

RESULTS

Of the 180 cases, 148 patients (82.2%) adapted to the denture in 2-3 weeks, 24 patients (13.3%) in 4-5 weeks, 8 patients (14.5%) in 5-6 weeks. The further observation were evaluated over 10-15 years with clinical satisfaction.

CONCLUSION

This method not only reserves the tooth structure, but also restores configuration and function of the lost tissues. It's really a constantly effective remedy.

A three-year clinical evaluation of two dentin bonding agents

BACKGROUND

A new restorative called a "giomer composite" has been introduced. The authors conducted a study to determine retention, anatomical form, caries, staining, marginal discoloration, marginal adaptation, surface roughness and sensitivity of giomer compared with those of a microfilled composite.

METHODS

The authors placed 40 sets of restorations randomly in canines and premolars in vivo. They used a giomer composite and a microfilled composite in erosion/abrasion/abfraction Class V lesions that were not altered with rotary instruments. They placed the restorations according to manufacturer's recommendations, and two calibrated examiners evaluated the restorations independently using modified U.S. Public Health Service criteria at baseline and at six, 18 and 36 months. The lesions receiving the restorations did not differ from each other in the amount of circumferential enamel present, the percentage of the surface area of dentin or lesion type.

RESULTS

There were no differences in the restorations at baseline, an evaluation made two weeks after placement. At 36 months, the giomer and microfilled composite restorations were not significantly different from one another in any of the eight criteria evaluated. The percentage agreement between examiners was at least 83 percent for each criterion in each evaluation period.

CONCLUSIONS

Both the giomer and the microfilled composite used in this study meet the clinical portion of the Acceptance Program Guidelines for Dentin and Enamel Adhesives Materials established by the American Dental Association.

CLINICAL IMPLICATIONS

Both the giomer and the microfilled composite used in this study can be used with confidence in Class V lesions.

A Technique for Simple and Aesthetic Treatment of Anterior Toothwear

This article describes a technique for treating anterior toothwear. The technique allows the placement of direct composite on the palatal surface of upper anterior teeth in an efficient and accurate manner. The advantages of an indirect wax-up technique and a direct intra-oral approach are combined to give an aesthetic and conservative result.

Clinical performance of a resin-modified glass-ionomer and two polyacid-modified resin composites in cervical lesions restorations: 1-year follow-up

The aim of this study was to assess the clinical performance of a resin-modified glass-ionomer cement (Vitremer) and two polyacid-modified resin composites (F2000 and Freedom) over 1 year. Nineteen patients with at least three cervical lesions were selected, providing an initial sample size of 87 restorations (29 per material), being 78 to non-carious and nine to carious lesions. Restorations were evaluated at baseline, 6 months and 1 year after placement, using modified US Public Health Service criteria: colour match, marginal discoloration, caries, anatomical form, marginal integrity and surface texture. At baseline, restorations were considered as acceptable for all criteria. At 1-year recall, 21 restorations per material were re-examined. Freedom was rated Bravo or Charlie for all the examined criteria and Vitremer earned an Alfa rating solely for the criterion caries. On the contrary, F2000 showed the best overall results, although presenting significant alteration in colour match. Statistical analysis of data was performed using chi-square and Mc Nemar tests. As to the evaluated periods, significant difference was observed solely between baseline and 1-year recall. Freedom and Vitremer were statistically different (P < 0.01) as to anatomical form and surface texture. For F2000, significant difference (P < 0.05) was noticed as to colour match and anatomical form. After 1-year follow-up, F2000 showed the most acceptable results as to the analysed criteria.