Quintessence International, 06/2006

In recent years the concept of minimally invasive dentistry has offered a more conservative approach to restoration of teeth with caries lesions. Several techniques have been suggested for treatment of proximal lesions, but their results have been less than ideal. The aim of this article is to present a new technique for ultraconservative restoration of small interproximal caries lesions that avoids the disadvantages of both the tunnel and the proximal slot restorative techniques. Two cases, of patients with high and low caries risk, are presented to illustrate the technique. The proposed technique can be considered the most conservative alternative to conventional Class 2 or slot-cavity treatment approaches. Keywords: caries lesion, caries risk, fluoride, minimally invasive dentistry, proximal lesion, resin composite

Objective: The aim of this in vitro study was to evaluate the effect of human plasma, compared to physiologic saline, on microtensile bond strengths of 5 self-conditioning dentin adhesives when used as a dentin perfusion medium. Method and Materials: One hundred and fifty extracted human third molars were prepared in a special manner allowing the simulation of intrapulpal pressure and dentin perfusion. The specimens were randomly divided into 10 experimental groups. Five groups were perfused with physiologic saline, while the others were perfused with diluted human plasma, each under constant hydrostatic pressure of 30 cm H2O. One saline group and 1 human plasma group was then assigned to each of the following dentin adhesives: Clearfil SE Bond (Kuraray), Clearfil Protect Bond (Kuraray), Xeno 3 (Dentsply), Futurabond NR (Voco), and iBond (Heraeus Kulzer). The microtensile bond strength for each group was evaluated using a Zwick universal testing machine 10 minutes after light curing. Results: Pairwise comparison showed a significant increase of bond strength in all human plasma-perfused subgroups (P < .05, Tukey's test). The influence of the different dentin adhesives was significant (P < .001, analysis of variance). The highest significant values were observed for Futurabond NR and iBond with human plasma (P < .05, closed test procedure). Conclusion: The use of human plasma might be a suitable alternative to imitate perfused dentin conditions in testing devices and might eliminate the discrepancy between different in vitro investigations focusing on bond strength of dentin adhesives. Keywords: dentin, dentin bonding agents, dentin perfusion, human plasma, microtensile bond strength, saline, self-conditioning

Objective: The aim of this study was to document sensory changes in the supraorbital, infraorbital, and mental nerve distributions following acute and chronic maxillary and frontal sinusitis. Method and Materials: Seven patients with a total of 14 infected sinuses were included in the study. Neurosensory function was evaluated by measuring the electrical detection threshold for large myelinated nerve fibers and heat detection thresholds for the assessment of the thin unmyelinated nerve fibers. The sensory tests were conducted in the infraorbital, supraorbital, and mental dermatomes. Patient evaluation included clinical examination and computerized tomographic imaging of the sinuses. Sinusitis symptoms of 1 month or less were considered acute, and symptoms that persisted for more than 3 months were considered chronic. Detection thresholds in 8 healthy volunteers served as controls. Results: Eight acute and 6 chronic sinusitis cases were diagnosed. Acute sinusitis produced bilateral large myelinated fiber hypersensitiv-ity (electrical) relative to healthy controls, with no significant change in the thin unmyelinated nerve fiber detection threshold (thermal). Chronic sinusitis resulted in large myelinated fiber hyposensitivity and thin myelinated fiber bilateral hyposensitivity, as compared to healthy controls. Conclusions: This study concurs with previous studies in finding that early inflammatory neuritis can produce large myelinated nerve fiber hypersensitivity, while long-lasting processes, presumably accompanied with early nerve damage, may result in hyposensitivity. Keywords: neuritis, neuropathic pain, quantitative sensory testing, sinusitis

Fiber-reinforced resin composites (FRCs) have been used to make frameworks to support particulate resin composite veneers in the replacement of missing teeth. Both prosthetic laboratory-fabricated and chairside-fabricated approaches have been used with varying degrees of success. The chairside FRC fixed partial denture has been mainly used for anterior tooth replacement where the emphasis is on esthetics rather than withstanding occlusal load. This article focuses on the use of this technology in the chairside replacement of premolars. The concept of using a prefabricated framework is described in detail. This approach allows for the efficient delivery of a consistently made chairside prosthesis. This is in contrast with the time-consuming and less consistent result of FRC framework fabrication directly in the mouth. The goal for this concept is to use a premade framework finalized by the provider at chairside to provide medium- to long-term posterior tooth replacement, with minimal abutment tooth reduction. Keywords: direct fixed partial denture, fiber-reinforced composite, particulate resin composite, prefabricated framework

The pregnant or breast-feeding patient presents a number of unique management problems for oral health care providers. Clinicians are responsible for providing safe and effective care for the mother, while also considering the safety of the fetus or newborn. They must consider the effects of medications, which may be distributed from the maternal plasma through the placenta to the fetus, or to breast milk, exposing the nursing infant to potentially dangerous concentrations. In addition, a number of maternal oral changes, requiring the attention of oral health care providers, may be observed as a consequence of the multiple physiologic changes associated with pregnancy. In view of the dual responsibility that oral health care providers face in treating the pregnant or breast-feeding patient, understanding the physiology of pregnancy, fetal development, potential oral complications of pregnancy, and the effects that dental intervention may have on the woman, her fetus, or her neonate are imperative. Keywords: oral hygiene, periodontitis, pregnancy, pregnancy gingivitis, pregnancy tumor, dental care/management, drugs

Objectives: The purpose was to measure the interstitial fluid pressure generated from tissue resistance during administration of local anesthetic solution at 4 anatomic locations within the oral cavity and to determine whether differences in soft tissue density affect interstitial fluid pressure when anesthetic solution is administered at a fixed flow rate. Method and Materials: A computer-controlled local anesthetic delivery device (CompuFlo, Milestone Scientific) that records and stores pressure data during a subcutaneous injection was used. Subjects consisted of adult patients seeking routine dental care that required local anesthesia. A total of 200 injections were administered and fluid pressure readings recorded. Injections were divided into 4 groups of 50: group 1-intraligamentary injections (PDL); group 2-palatal injection, anterior middle superior alveolar nerve block; group 3-supraperiosteal buccal infiltrations, and group 4-inferior alveolar nerve blocks. For all injections 1 cartridge (1.8 mL) of lidocaine containing 1:100,000 concentration of epinephrine was administered at a fixed flow rate of 0.005 mL/sec. Results: One-way analysis of variance (ANOVA) revealed that the data were statistically significant (P < .001), with corresponding mean values as follows: group 1, 293.98 psi; group 2, 68.16 psi; group 3, 11.50 psi, and group 4, 9.76 psi (F-ratio of 2371.933). Groups 1 and 2 were different from all other groups; groups 3 and 4 were not statistically different from each other. Conclusion: Interstitial resistance to fluid pressure can be measured during administration of 4 different local anesthetic injections used in dentistry. Based on fluid pressure and tissue resistance characteristics, a soft tissue density classification was defined. Keywords: computer-controlled drug delivery system, computer-controlled local anesthetic delivery system, dental, injection pressure, local anesthesia, local anesthetic technique, tissue pressure

Objective: The purpose of this in vitro study was to investigate fracture resistance in teeth restored with cast posts and cores with and without ferrule and using 2 different luting cements. Method and Materials: Forty intact extracted maxillary premolars were endodontically treated after their crowns were removed 2 mm from the cementoenamel junction. Specimens were embedded in acrylic resin blocks, in aluminum cylinders, 2.00 mm apical to the cementoenamel junction. Twenty specimens were ferruled. Within this group, half of the posts and cores were cemented with zinc phosphate cement, while the other half were cemented with resin cement. The same procedures were followed for the nonferruled group. The posts and cores were cast in gold alloy. Specimens were placed in a universal testing machine, and loads were applied at an angle of 45 degrees and a rate of 1 mm/min until the teeth fractured. Analysis of variance and Tukey tests were used for statistical analysis; level of significance was established at 5%. Results: There was no association between type of cement and cervical ferrule; ferruled specimens showed greater resistance than nonferruled ones, regardless of the cement used. Conclusion: A 2-mm cervical ferrule improves fracture resistance of restored teeth, but the type of luting cement used does not seem to affect resistance. Keywords: cementation, cements, posts and cores, post-and-core design, prosthesis, tooth fracture resistance

Space closure from distal to mesial is one of the most difficult orthodontic tasks. Tooth-borne anchorage limits the scale of tooth movement. Extraoral or intraoral appliances are used especially for unilateral space closure. As an alternative to conventional mesialization appliances, osseointegrated implants may be used for maximum anchorage in orthodontic treatment. Temporary implants inserted in the palatal suture are most common in maxillary treatment. In the case presented, temporary implants were placed in the palatal bone of a 17-year-old male patient with hypodontia of the mandibular central incisors and second premolars and the maxillary left second premolar for mesialization of the molars. Slight irritations of the tongue were registered in the first 2 weeks of use of the palatal implant. There were no other effects during treatment. Keywords: anchorage, intraoral appliance, mesialization, orthodontic implants