Quintessence International, 07/2000

Objective: The purpose of this study was to evaluate the feasibility and performance of tunnel restorations placed in routine public dental service. Method and materials: A total of 420 small approximal lesions received tunnel restorations 12 general practitioners. Three hundred two restorations in 179 patients were available for evaluation after a minimum period of 24 months. The restorations were evaluated by modified US Public Health Service criteria. Results: After service periods up to 54 months, 57% of the restorations were found to be clinically and radiographically acceptable. The remainder had already been replaced or were assessed as unacceptable. High levels of carious activity and internal-type preparations resulted in the poorest prognosis. The success rates varied considerably among the operators, but these differences did not reach statistical significance. Conclusion: The indications for use of the tunnel restoration technique for the treatment of primary approximal lesions seem to be limited at present. Partial tunnel restorations may have a somewhat better prognosis than the internal tunnels, but high carious activity has a detrimental effect. Tunnel restorations may be considered for particularly cooperative patients with a low caries rate as a semipermanent treatment for small lesions.

The purpose of this article is to introduce an objective method for quantifying cervical dentin hypersensitivity. Air emissions from a standard air-water syringe or a syringe with a Fluid Control Block are directed toward the cervices of teeth at a 45-degree angle to the long axis of test teeth from a distance of 0.5 cm for 0.5 to 1.0 second. An air indexing method has been developed to quantify threshold patient response values for individual teeth to this defined air stimulus. The air indexing method, using the Fluid Control Block, offers the clinician objective information to compare cervical dentin hypersensitivity before and after treatment for this common, painful condition. Keywords: abfractive lesion (abfraction), air index mapping, air indexing method, cervical dentin hypersensitivity, Fluid Conlrol Block, hydrodynamic theory, threshold patient response

Objective: The purpose of this retrospective study was to evaluate the association between cervical dentin hypersensitivity and the presence of abfractive lesions. Method and materials: Written records and study casts for 250 active-care patients, selected alphabetically, were analyzed for the clinical detection of abfractive lesions and cervical dentin hypersensitivity from 1979 until 1996. Clinical diagnosis of abfractive lesions was made according to existing literature descriptions of these hard tissue lesions. Cervical dentin hypersensitivity was diagnosed when a verified positive threshold patient response was found during tooth evaluation by the air indexing method. Patient groups I and II were formed solely on the basis of the presence or absence, respectively, of a verified positive threshold patient response of cervical dentin to air. Results: A significant association was found between air-indexed cervical hypersensitivity and the presence of abfractive lesions. The primary locations for both cervical hypersensitivity and abfractive lesions were the buccal surfaces of posterior teeth. Conclusion: This long-term retrospective study found a positive association between cervical dentin hypersensitivity and abfractive lesions. The correlative nature of this study suggests the need for further investigation. Keywords: abfractive lesion, air indexing method, Fluid Control Block, verified positive threshold patient response

An alternative hypothesis to abrasion and erosion for the pathogenesis of noncarious cervical lesions was put forward in 1984; the so-called occlusal theory suggested that tensile stresses from occlusal overload could be involved in the pathogenesis of noncarious cervical lesions and that bending stresses applied to teeth could cause disruption of the surface enamel, resulting in increased susceptibility to dissolution and abrasion at the affected sites and in the development of wedge-shaped lesions. This theory has gained increased acceptance in recent years, although absolute scientific evidence has been scant. These lesions also occur in animals, in particular, the domestic cat, in which they are called feline odontoclastic resorptive lesions. A variety of theories about pathogenesis of these lesions have been put forward, but there is some evidence that occlusal overload may be a contributory factor in the development of an inflammatory response in the periodontal membrane and the presence of enzymes associated with resorption in the gingival crevice. Further investigation may help define a common etiology between the pathogenesis of feline odontoclastic resorptive lesions and noncarious cervical lesions.

Along with osseointegration and restoration of function, the patient's subjective satisfaction with the esthetic result is a touchstone of the success of implant therapy. Although esthetic restoration of natural teeth can be achieved routinely through appropriate tooth preparation and a natural-looking design on the part of the dental laboratory, the road to success is much more complicated with implants, because of atrophy of bone and mucosa. Surgical techniques, paths of incision, and useful instruments for implant therapy are described, from implant placement to exposure. These methods help to provide durable, functional, and esthetic results.

Objective: This study was undertaken to determine the relative shear bond strengths and microleakage of 4 bonding agents to dentin and amalgam and to investigate the bonding to dentin through confocal laser scanning microscopy. Method and materials: Sixty noncarious molars were restored with 1 of 4 different systems, and the shear bond strengths were determined. For the microleakage study, Class V amalgam restorations were placed in 60 noncarious teeth. The specimens were thermocycled, the teeth were sectioned, and dye penetration was assessed. For confocal examinations, the first component of the bonding adhesives was labeled with rhodamine B. Each of the adhesives was applied to 3 dentin specimens, which were examined under a confocal laser scanning microscope. Results: Of the 4 restorative systems tested, AmalgamBond Plus + HPA and Prime & Bond 2.1/base-catalyst showed significantly higher shear bond strengths. Prime & Bond 2.1/base-catalyst had the lowest microleakage value, which was significantly lower than that of AmalgamBond Plus + HPA and AmalgamBond Plus. AmalgamBond Plus + HPA had the highest variation in both the bond strength and microleakage values. Confocal laser scanning microscopy revealed tag formation, penetration of the bonding agents deep into the tubules, and hybrid layer formation for all 4 bonding systems. Conclusion: The 2 best systems, Prime & Bond 2.1/base-catalyst and, to a lesser extent, AmalgamBond Plus + HPA, utilized a supplemental bonding agent.