Ultramorphological assessment of dentin-resin interface after use of simplified adhesives.

This study assessed dentin-resin interface integration in Class I cavities restored with simplified adhesives by using a focused ion-beam milling (FIB) and transmission electron microscope (TEM). Class I cavities (1.5-mm depth with dentin thickness of ∼0.5 mm, 4-mm length, and 2-mm width) were prepared on freshly extracted, sound human molars. Two all-in-one adhesive systems (Scotchbond/Single Bond Universal [SUD] and Xeno-V(+) [X5D]) were used and compared with a two-step etch-and-rinse system (Prime&Bond NT [NTD]). The adhesives were applied according to the manufacturers' guidelines. A universal resin composite (Filtek Z350 XT Universal) was used to restore the cavities in one bulk filling and was irradiated at 550 mW/cm(2) for 40 seconds by a quartz-tungsten-halogen light (Optilux 501). After exposure to liquid nitrogen coolant, the specimens were milled to nanoscale thickness by FIB to view and then assess the area of dentin-resin interface by TEM. Unlike the unfilled X5D, a noticeably smooth transition zone at the dentin-resin interface was shown for the SUD and NTD adhesives. The SUD demonstrated an uneven hybrid layer with clearly demineralized collagen bundles. Ultramorphologically, dispersed needlelike apatite crystals were detected within the partially demineralized dentin or the hybrid layer of both compositionally different all-in-one simplified adhesives. Conversely, these crystals were entirely absent from the hybrid layer of the etch-and-rinse NTD adhesive. In the X5D group, a bright band was noted beneath the hybrid layer. The methacryloxydecyl dihydrogen phosphate monomer containing ultramild self-etch adhesive (SUD) was still validated in terms of its capability in dentin adhesion.

Five-year longitudinal assessment of the prognosis of apical microsurgery.

INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment apical periodontitis. Knowledge of the long-term prognosis is necessary when weighing apical surgery against alternative treatments. This study assessed the 5-year outcome of apical surgery and its predictors in a cohort for which the 1-year outcome was previously reported. METHODS: Apical microsurgery procedures were uniformly performed using SuperEBA (Staident International, Staines, UK) or mineral trioxide aggregate (MTA) (ProRoot MTA; Dentsply Tulsa Dental Specialties, Tulsa, OK) root-end fillings or alternatively Retroplast capping (Retroplast Trading, Rorvig, Denmark). Subjects examined at 1 year (n = 191) were invited for the 5-year clinical and radiographic examination. Based on blinded, independent assessment by 3 calibrated examiners, the dichotomous outcome (healed or nonhealed) was determined and associated with patient-, tooth-, and treatment-related variables using logistic regression. RESULTS: At the 5-year follow-up, 9 of 191 teeth were unavailable, 12 of 191 teeth were extracted, and 170 of 191 teeth were examined (87.6% recall rate). A total of 129 of 170 teeth were healed (75.9%) compared with 83.8% at 1 year, and 85.3% were asymptomatic. Two significant outcome predictors were identified: the mesial-distal bone level at ≤ 3 mm versus >3 mm from the cementoenamel junction (78.2% vs 52.9% healed, respectively; odds ratio = 5.10; confidence interval, 1.67-16.21; P < .02) and root-end fillings with ProRoot MTA versus SuperEBA (86.4% vs. 67.3% healed, respectively; odds ratio = 7.65; confidence interval, 2.60-25.27; P < .004). CONCLUSIONS: This study suggested that the 5-year prognosis after apical microsurgery was 8% poorer than assessed at 1 year. It also suggested that the prognosis was significantly impacted by the interproximal bone levels at the treated tooth and by the type of root-end filling material used.

Comparative assessment of the sealing ability of Nd:YAG laser versus a new desensitizing agent in human dentinal tubules: a pilot study.

Dentinal hypersensitivity is a painful condition that occurs following periodontal treatment. Many treatment alternatives have been considered for this problem, including treatments with laser and dentinal adhesives. This study compared the sealing ability of Nd:YAG laser versus a new resin in scanning electron microscopy (SEM) micrographs. Ten human premolars were sectioned yielding 30 specimens of each premolar, which were randomly divided into three groups. The laser group was irradiated by Nd:YAG laser (1 W, 10 Hz, 60 s), the resin group was treated with the new Seal & Protect resin according to the manufacturer's instructions, and the third group served as the control group and did not receive any interventions. After preparation and gold coating of the samples, they were photographed by SEM at two magnifications (1500× and 4000×). The number and diameter (µm) of the dentinal tubules were recorded in selected fields, and analysis of variance (ANOVA) and Tukey tests were used to determine significant differences between groups. The ANOVA results revealed significant differences in both the mean number (P < 0.001) and diameter (P < 0.05) among the three groups. Further statistical analysis showed a significant difference between the laser group and the resin group in both outcome measures (P < 0.05). Thus, both Nd:YAG laser and the new resin reduced the number and diameter of open dentinal tubules, a result that also explains the desensitization mechanism of these interventions. We further conclude that application of the new resin is more effective than Nd:YAG laser in minimizing the number and diameter of exposed dentinal tubules.

Qualitative and quantitative radiographic assessment of sealed carious dentin: a 10-year prospective study.

OBJECTIVE: The objective of this study was to assess radiographic outcomes after partial carious dentin removal performed in deep caries lesions over a 10-year period. STUDY DESIGN: Baseline image was compared to 3 follow-up radiographs (at 6-7 months, 3 years, and 10 years). Tertiary dentin deposition and lesion depth were qualitatively assessed. Radiographic density changes in the radiolucent zone (RZ) beneath the restoration were quantitatively compared to the control areas (CA) using digital subtraction radiography (Friedman repeated-measures analysis of variance). RESULTS: A total of 13 teeth were evaluated. In most cases, lesion depth remained unchanged or decreased (12/13) and tertiary dentin formation was observed (10/13) after the 10-year follow-up. Differences between RZ and CA at the 6- to 7-month and 3-year follow-up periods were similar but significantly lower than those at the 10-year assessment. CONCLUSIONS: Sealing of carious dentin arrested the caries process, promoted deposition of tertiary dentin, and induced mineral gain in the radiolucent zone.

An audit of dentine hypersensitivity treatments in six general dental practices in Scotland.

AIMS: This investigation sought to: (a) determine the agents used by nine dentists to treat dentine hypersensitivity and measure their effectiveness; (b) evaluate the adoptive ease and apparent success of the most effective treatment when used by all nine dentists; and (c) validate a novel categorical ranking score for dentine hypersensitivity. METHODS: A clinical audit methodology was used in the setting of general dental practice. In the initial data-collection round, patients presenting with dentine hypersensitivity were treated using the dentist's favoured regimen. Evaluation of agent effectiveness was made by patient completion of a pre- and post-treatment visual analogue scale (VAS) for the frequency (f) and severity (s) of hypersensitivity. A four-point categorical ranking scale (CRS) was also used to assess the impact of hypersensitivity upon lifestyle (L) (1=No sensitivity/effect on what I eat/drink; 2=Sometimes sensitive, rarely interfering with what I eat/drink; 3=Sometimes sensitive, occasionally interfering with what I eat/drink; 4=Always sensitive, always interfering with what I eat/drink). The most successful treatment was determined and used by all participating dentists. Its effectiveness was then assessed using the same criteria. RESULTS: Four agents were routinely used to treat hypersensitivity: (Duraphat (D) (Colgate), Duraphat & Sensodyne (DS) (GlaxoSmithKline), Sensodyne (S) (GlaxoSmithKline), Seal & Protect (SP) (De Trey, Dentsply). All produced statistically significant (P<0.001) reductions in VAS (Tukey) and CRS (Kruskal-Wallis) scores, except for DS and S. Of these, the greatest percentage reduction was seen for SP (f=72.01%, s=71.19%, L=45.98%). When SP was applied by all dentists, similar percentage reductions were seen (f=68.74%, s=75.85%, L=38.33%). The CRS, in both data-collection rounds, correlated well with the corresponding VAS scores (Spearman R for f=0.77 (P<0.001) and for s=0.80 (P<0.001). CONCLUSION: For the dentists in this audit, the use of SP was found to be reliable and predictable. The CRS provided a simple and reliable measure of dentine hypersensitivity. Subject to validation in a larger study, this could be used in a future audit as an alternative to multiple VAS scores.

Green Or preparation in dentin hypersensitivity treatment.

The effectiveness of Green Or preparation in the treatment of cervical dental hypersensitivity was evaluated. This problem is difficult for patients and for dentists because of dual and unknown methods of treatment. The preparation was used in 30 patients between the ages of 20 and 70 years on 240 teeth with exposed and hypersensitive necks. The obtained results are acceptable, as total elimination of hypersensitivity was attained in 85% of cases, partial reduction of hypersensitivity in 15% cases.

Sealants and preventive restorations: review of effectiveness and clinical changes for improvement.

Sealants are effective caries-preventive agents to the extent they remain bonded to teeth. Preventive resin restorations (PRR) have a proven record, but are susceptible to failure as the overlying sealant fails. Careful analyses of studies reveal a measurable failure rate of sealants (5-10% per year) that must be addressed. Even under the best of circumstances, sealants fail. Therefore, dentistry (as well as third-party systems) must accept that sealants need vigilant recall and proper preventive maintenance. In addition, it is clear that cost-effective use of sealants will involve selective application on teeth with the greatest caries risk. Caries risk analysis of the patient as well as the tooth is an essential step in the treatment planning process. To improve sealant success, new material advances are suggested. Data from studies using an intermediate layer of dentin bonding agent between etched enamel and sealant show dramatic reduction of failure for sealants, particularly in instances of molars judged difficult to seal due to early stage of eruption.