Esthetic Crown Lengthening Surgery - A 30-Year Retrospective and Lessons Learned.

Esthetic crown lengthening (ECL) surgery has been available to our profession for more than 30 years. The objective of this article is to discuss the author's evolution in the techniques associated with ECL surgery. Several technical modifications related to initial incision, ostectomy, and tissue placement will be discussed. In addition, reasons for tissue rebound will be discussed.

Tensile bond strength of dental adhesives to dentin and enamel.

This study compared the tensile bond strengths of an unfilled resin bonding agent and four proprietary dentin bonding agents to dentin and acid-etched enamel. Forty-eight hours after bonding, 10 dentin-bonded teeth and 10 enamel-bonded teeth for each material were loaded in tension in an Instron Universal Testing Machine until bond failure. The remaining specimens were stored in a water bath for six months and then tested in a similar manner. At the end of six months, Universal Bond and Tenure (3-step) had bond strengths significantly greater than those of the other agents. All bonding agents, except Tenure (3-step), showed a significant decrease in tensile bond strength to both dentin and enamel after six months (p less than 0.0001).

Clinical crown length changes from age 12-19 years: a longitudinal study.

OBJECTIVE: The objective of this study was to investigate the relationship between age, gender and clinical crown length using a longitudinal study design. METHOD: Four hundred and fifty-six sets of study models initially obtained for a large prospective longitudinal cohort study of orthodontic needs were examined. Each set of models corresponded to subjects at three different ages: 11-12, 14-15 and 18-19years old. The clinical crown height of the maxillary right central incisor (11), maxillary right canine (13), maxillary left lateral incisor (22) and mandibular left central incisor (31) was measured from gingival crest to the incisal edge using digital calipers. RESULTS: Analysis revealed a significant (p<0.0001) age effect on crown length for all four teeth investigated. A significant gender effect was found in relation to the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor. Pairwise comparisons of the means for each age group for the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor revealed significant (p<0. 0001) increases in clinical crown length between each assessment period. CONCLUSION: The findings of the present study indicate that, the process of passive eruption, resulting in increased clinical crown length appears to continue throughout the teenage years. This finding is considered to be of importance to the clinician making treatment decisions for teenagers and young adults requiring treatment in the anterior segments of the mouth.

Guidelines for the restoration of endodontically treated teeth.

Much confusion exists in the dental community regarding the restoration of endodontically treated teeth; few review articles present succinct guidelines for the restoration of these teeth. This article reviews the literature and presents guidelines for restoration of endodontically treated teeth.

The placement of bases beneath amalgam restorations: review of literature and recommendations for use.

On the basis of the literature, it can be concluded that there are no absolute rules regarding the placement of bases under amalgam restorations. The following recommendations are offered: A base should not be used unless its use is indicated clearly. When a base is indicated, it should be used with the minimum thickness necessary to achieve the desired result. Lost dentin should not be replaced with a base in an attempt to simulate an ideal preparation. A stronger base should not be placed over a weaker base, for strength. The entire base is only as strong as the weakest component. Covering the entire pulpal floor with a base should be avoided. Sound dentin surrounding the base should be left so that the amalgam restoration is supported by dentin as much as possible.

Success of overdentures and prevention of failure.

Placement of dentures over selected retained teeth has become a commonly used treatment in dentistry. The relationship between the overdenture and the areas of periodontal, endodontic, restorative, and prosthodontic diagnosis and treatment has been discussed. Within each area, aspects of treatment that are crucial to success of the overdenture have been identified. It is suggested that the two most important concerns are adequate diagnosis and maintenance. The combination of a properly diagnosed case and a motivated patient, along with extreme attention to detail during treatment, will enhance the prospect of success.

Symmetrical widening of the periodontal ligament space in a patient with multiple systemic problems.

Progressive systemic sclerosis is an uncommon disease that affects the collagen in multiple organ systems. Characteristic oral manifestations that may complicate dental treatment include limited opening, TMJ dysfunction, mucogingival problems, xerostomia, and pathological resorption of the mandible.

Retention and resistance features for complex amalgam restorations.

Although not absolute, there are indications for each of the retention and resistance features described. Amalgapins and circumferential slots have their greatest indication in teeth with short clinical crowns and in cusps that have been reduced 2-3 mm for coverage with amalgam. In these situations, slots provide more resistance than amalgapins and amalgam inserts. When amalgapins or slots are used as the only retention and resistance features, the restoration is susceptible to early fracture during matrix removal. When the technical requirements for placement of vertical pins can be met, they provide excellent retention and resistance form. Vertical pins should be placed at least 0.5 mm inside the dentinoenamel junction, at a depth of approximately 2 mm, and should protrude from the tooth approximately 2 mm. However, there are inherent risks involved with pin placement; these include crazing of tooth structure, perforation into the pulp or periodontium, and weakening of the amalgam restoration over the pins. The use of both vertical and horizontal pins may be limited by inadequate access; in these cases, alternate devices should be used. When a cusp has been reduced and increased resistance is needed, a ledge or peripheral step may be indicated. It must be remembered that this feature will result in a greater display of amalgam and may be esthetically unacceptable on a facial cusp. If esthetic appearance is a factor, horizontal pins may be used to reinforce a remaining facial cusp. Horizontal pins may also be used to splint or tie a remaining cusp to the restoration.(ABSTRACT TRUNCATED AT 250 WORDS)

The performance of bonded vs. pin-retained complex amalgam restorations: a five-year clinical evaluation.

BACKGROUND: The authors compared the clinical performance of complex amalgam restorations, replacing at least one cusp--retained either mechanically with self-threading pins or bonded--with a filled, 4-methacryloxyethyl trimellitate anhydride, or 4-META-based resin designed for amalgam bonding. METHODS: The authors placed 60 amalgam restorations (28 pin-retained and 32 bonded), each restoration replacing at least one cusp. They used self-threading stainless steel pins in the pin-retained group and a filled, 4-META-based bonding resin in the bonded group. For both groups, the authors left in place any retention form remaining after removal of an old restoration but did not enhance it. RESULTS: At four years, six restorations had failed. At five years, of the 40 restorations available for evaluation, three had failed, for a total of nine failed restorations; seven of those were pin-retained and two were bonded. Using the Fisher exact test to compare the groups at five years, the authors found no significant difference in failure rate, marginal adaptation, marginal discoloration, secondary caries, tooth sensitivity or tooth vitality. CONCLUSIONS: At five years, there was no difference in the performance of pin-retained amalgam restorations and bonded amalgam restorations. This study will be continued for at least a sixth year. CLINICAL IMPLICATIONS: Bonding with a filled, 4-META-based bonding resin appears to be a satisfactory method of retaining large amalgam restorations replacing cusps.

Intraoral repair of the fractured porcelain restoration.

Until recently, there was no predictable technique for repairing the fractured porcelain restoration. However, with the advent of many new products related to bonding porcelain, there are techniques available today to repair fractured porcelain with moderate expectations of success.

Fracture resistance of reinforced glass ionomer as a buildup material.

This study in vitro investigated the fracture resistance of two reinforced glass ionomers and amalgam when used as core-buildup materials. Four-pin buildups using the three materials were placed in human molar teeth and prepared for gold crowns. The crowns were cemented and the teeth were compressed at 45 degrees to failure. There was no significant difference found in the fracture resistance of the three materials.

In vitro comparison of filled and unfilled universal bonding agents of amalgam to dentin.

In this study, four different adhesive amalgam systems were compared(Amalgambond Plus, Amalgambond Plus with HPA, All-Bond 2, and All-Bond 2 with Liner-F) regarding their ability to bond amalgam to freshly prepared dentinal surfaces. The two groups that yielded the highest mean bond strengths, Amalgambond Plus with HPA and All-Bond 2 with Liner-F, were the only two groups in comparison that were not statistically different (P > 0.05). The use of the filled resin bonding agents created significantly higher bond strengths between tooth and freshly triturated amalgam than the unfilled resin bonding agents. Further study is required to determine: a) the exact nature and mechanism of the bonds, and b) clinical in vivo presence and longevity of the bonds.

Effect of distribution of resistance features in complex amalgam restorations.

This study measured fracture resistance of complex amalgam restorations when pins or amalgapins were either distributed around the preparation or concentrated in one area of the preparation. The occlusal surfaces of 80 extracted molars were ground flat to 2 mm occlusal to the cementoenamel junction (CEJ). Roots were notched and embedded. Teeth were sized and distributed equally into eight groups (n = 10). Resistance features, four TMS stainless steel Regular pins or four amalgapin channels, were inserted into each molar. Resistance features were either distributed at the four line angles of each molar or clustered at two line angles. Matrices were applied, and amalgam was mechanically condensed into the matrices. Restorations were adjusted to a 4 mm vertical height and flat occlusal surfaces. A load was applied to each restoration at either a 45 degrees or a 90 degrees angle to the long axis of the tooth. Distributed pins provided significantly more resistance than clustered pins in groups tested at 90 degrees. Resistance to fracture in all groups loaded at 45 degrees and in amalgapin groups was not significantly affected by distribution of resistance features. Pins provided significantly more resistance than amalgapins at both angles of testing.

Repair bond strength of glass-ionomer restoratives.

The repair bond strength of three different brands of glass-ionomer restorative was tested over time. In this laboratory study, immediate repair of glass ionomer was possible with all three brands; however, over time the repair bond strengths decreased at different rates for the different materials.

Shear bond strength of composite resin to microetched metal with five newer-generation bonding agents.

The purpose of this study was to determine the shear bond strength of a hybrid composite resin to a nickel-chrome-beryllium (Ni-Cr-Be) alloy, using five of the newer-generation bonding agents: Optibond, All-Bond 2, Prisma Universal Bond 3, Restobond 4, and Amalgambond Plus with HPA. For each bonding system 10 samples of metal were microetched with 50-micron aluminum oxide prior to the placement of the bonding agent and resin. The shear bond strength was tested, and the results showed that Amalgambond Plus with HPA developed the strongest bond at 18.81 +/- 3.924 MPa, followed by All-Bond 2 at 14.33 +/- 3.408, Optibond at 13.97 +/- 1.508, Prisma Universal Bond 3 at 12.51 +/- 1.845, and Restobond 4 at 10.29 +/- 1.407.

Fracture resistance of endodontically-treated cuspids.

The purpose of this in vitro study was to determine the optimum method for treating an endodontically treated cuspid prior to placement of a crown. Sixty extracted human maxillary and mandibular cuspid teeth were divided into groups of 10. In groups A and B, the crowns were removed at the CEJ and post amalgam cores were placed with #5 Paraposts (Group A) and #120 tapered Ticonium Endowels (Group B). The remaining groups received the following treatments: Group C--gutta percha endodontic fillings, Group D--bonded composite (Fluoro-Core) in the access preparations, Group E--#100 Ticonium Endowels, and Group F--untreated control group. All teeth were prepared for and received cemented gold crowns, were mounted in methyl methacrylate and were stressed at 45 degrees to failure in an Instron machine. Mean fracture strengths (Newtons) were: Group A--500, Group B--530, Group C--520, Group D--510, Group E--680, Group F--580. Results indicated that when the coronal tooth structure was removed, there was no statistical difference (P < 0.05) between the Parapost and Endowel core buildup groups. Although Group E (intact crowns+Endowel posts) displayed higher mean fracture resistance than all other groups, there was no statistical difference (P < 0.05) due to the large range.

Esthetic gingival recontouring--a plea for honesty.

There continues to be a tremendous amount of confusion in the dental literature and among practitioners regarding the diagnosis and treatment of gingival discontinuities. The purpose of this article is to present a rationale for gingival recontouring, illustrated by a case report. A patient requested gingival recontouring. Because the preoperative evaluation was inadequate, a simple gingivectomy procedure was performed. After healing, the tissue had rebounded to its preoperative levels. The patient was then evaluated more comprehensively, and gingival recontouring was accomplished with a mucoperiosteal flap and osseous recontouring. The tissue subsequently healed at the correct position and remained stable. To reliably perform gingival recontouring procedures, the dentist must have a clear understanding of the biologic width. By using diagnostic bone sounding, the practitioner can determine the appropriate surgical procedure that will ensure an esthetic and stable postoperative result.

Color characterization of porcelain veneers.

Porcelain veneers have become a popular treatment modality in recent years. A common problem associated with these restorations is the inability of the dentist to reproduce the polychromatic appearance of a natural tooth with a porcelain veneer. It is the purpose of this article to describe several methods that may be used to transform a monochromatic porcelain veneer into a polychromatic restoration that approaches the beauty of a natural tooth.

Altered passive eruption: an etiology of short clinical crowns.

The gingival complex plays a vital role in the overall beauty of a smile. To predictably achieve a successful esthetic and functional result, the dentist must be able to precisely predict the treatment outcome based on biologic determinants. In this article, the biologic requirements for gingival health are discussed. In addition, a differential diagnosis for excess gingival display and treatment options for this condition are discussed.

Clinical evaluation of a dentinal adhesive system: three-year results.

The dentinal adhesive Scotchbond 2 was evaluated with the microfilled composite resin Silux in cervical and root caries lesions for up to 3 years. Clinical criteria evaluated included retention, marginal integrity, marginal discoloration, color match, anatomic form, recurrent caries, gingival response, and postoperative sensitivity. Overall, the adhesive demonstrated improved performance over earlier dentinal adhesive systems. Retention was greatest at 3 years when available enamel margins had been etched (93%) and when root caries lesions (97%) had been restored. Other criteria were reported as generally favorable. Early findings suggest that the level of development of sclerotic dentin may influence behavior of the adhesive. The greatest difficulty was noted in lesions presenting with heavy sclerotic dentin.