ABSTRACT
OBJECTIVE: The shear bond strength of adhesives applied to dentin was investigated after irradiation with an erbium-doped yttrium aluminum garnet (Er:YAG) laser. METHODS: Superficial and deep dentin specimens from human molars were treated either with carbide bur or an Er:YAG laser. Two etch and rinse adhesives (Single Bond and XP Bond) and two self-etch adhesives (Prompt L-Pop and Xeno III) were employed to bond the composite. Shear bond strength (SBS) was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure patterns and modes were analyzed and evaluated using a stereomicroscope. In addition, samples were processed for Scanning Electron Microscopy SEM evaluation. A linear mixed model was used, and pairwise comparisons were made using the Bonferroni test. RESULTS: Results showed significant differences between the levels of dentin treatment (p=.01) in carbide bur-cut dentin and lased dentin, as well as significant interaction effects due to the depth of dentin and the bonding system used. The etch and rinse adhesives bonded less effectively with lased dentin than with carbide bur-cut dentin, while self-etch adhesives bonded equally well with lased and bur-cut superficial dentin but much less effectively with lased deep dentin than with bur-cut deep dentin. SEM revealed a predominantly adhesive failure mode in laser-ablated fractured specimens, while a mixed failure mode was apparent in the bur-cut fractured specimens. CONCLUSIONS: Cavities prepared by laser seem less receptive to adhesive procedures than conventional bur-cut cavities.
ABSTRACT
The agenesis of maxillary lateral incisors is a common developmental anomaly and represents a clinical problem impairing dental esthetics and function from a very young age. Several dental specialties deal with the management of this clinical problem because a multidisciplinary approach can cover the complete dental needs of patients with dental agenesis. There is controversy, however, about whether missing lateral incisor spaces should be orthodontically opened or closed using permanent canines to replace the missing teeth. The article presents a review of the existing literature about the prevalence, etiology, diagnostic evaluation, and treatment strategy of maxillary lateral incisor agenesis. Also, this article aims to present the key determinants leading to selection of space opening or closure and to report professional judgments and layperson perception concerning the available treatment alternatives. The English-language literature associated with this topic was searched via PubMed. The articles retrieved were then reviewed with an attempt to fulfill the aims of this review. Maxillary lateral incisors are one of the most common congenitally missing teeth, and to date, the origin of their agenesis has not been completely identified. Prompt diagnosis and careful evaluation of treatment determinants through a multidisciplinary approach are essential for the proper management of clinical problems. Each of the available means of rehabilitation has its own advantages, disadvantages, indications, and limitations. The configuration of the treatment plan should be devoid of clinician biases, whereas patients' realistic expectations should be taken into account.
