Eighty extracted, noncarious premolars were restored with one of 20 different combinations of restorative materials: a high- or low-copper amalgam, unlined or lined with one of five bases, and varnished or unvarnished. The teeth were aged in 1% NaCl and after 3 months and 1 year the seal material deposited on the cut tooth cavity surface and the surface of the amalgam restoration was analyzed by use of energy dispersive x-ray analysis. Atomic weight percentages of marginal seal elements were statistically examined with ANOVA and Tukey's test with significance set at p < 0.05. The results indicated that only one type of seal was formed centered around tin. More marginal seal material was present in the 1-year specimens. Restoration materials used affected the deposition rate of marginal seal material. Low-copper amalgam-restored teeth formed more seal material with significantly greater amounts of chlorine and tin. Less marginal seal material was found in varnished cavities. A calcium hydroxide base produced a thick marginal seal with a significantly different composition of elements compared with the unlined and zinc-based specimens. Tin in Poly-F Plus polycarboxylate cement did not significantly increase the tin content of the marginal seal. Base materials can play a role in determining crevice pH. The findings have bearing on improved longevity of amalgam restorations.
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http://dx.doi.org/10.1016/s0022-3913(05)80208-2 | DOI Listing |
Dent J (Basel)
January 2025
Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.
: The success of treatment and prevention for secondary caries hinges significantly on the techniques employed in Class II composite restoration. Additionally, the location of the restored tooth within the oral cavity has emerged as a potential factor determining the quality of the restoration. A comprehensive understanding of these interrelated variables is crucial for advancing the efficacy and durability of dental composite restorations.
View Article and Find Full Text PDFContemp Clin Dent
December 2024
Department of Pediatric and Preventive Dentistry, K.M. Shah Dental College and Hospital, Sumandeep Vidyapeeth (Deemed to be University), Vadodara, Gujarat, India.
Background: Preventive dental procedures are cornerstones of caries management.
Introduction: This research aims to analyze the clinical effectiveness of pit and fissure sealants when applied to etched enamel pretreated with solvents compared to the conventional etch and seal technique.
Subjects And Methods: Children and adolescents with clinically healthy occlusal surfaces or noncavitated occlusal carious lesions on permanent first and/or second molars in all four quadrants were randomly allocated into four groups.
BMC Oral Health
January 2025
Department of Endodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Objectives: This study aimed to compare the marginal adaptation of a cold ceramic (CC) sealer with the single-cone obturation technique with that of an AH-26 sealer with the lateral compaction technique in single-canal teeth.
Materials And Methods: In this in vitro experimental study, the root canals of 24 extracted single-rooted single-canal teeth were instrumented to F3 files by the crown-down technique and randomly assigned to 2 groups (n = 12). The root canals were obturated with a CC sealer and single-cone obturation technique with 4% gutta-percha in group 1 and with an AH-26 sealer and lateral compaction technique with 2% gutta-percha in group 2.
Sci Rep
January 2025
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, 02134, USA.
Many aquatic organisms utilize suction-based organs to adhere to diverse substrates in unpredictable environments. For multiple fish species, these adhesive discs include a softer disc margin consisting of surface structures called papillae, which stabilize and seal on variable substrates. The size, arrangement, and density of these papillae are quite diverse among different species, generating complex disc patterns produced by these structures.
View Article and Find Full Text PDFLangenbecks Arch Surg
December 2024
Department of General Surgery, Huashan Hospital, Fudan University, No. 12 Middle Urumqi Road, Shanghai, 200040, China.
Background: Laparoscopic total gastrectomy (LTG) is still limited because intracorporeal oesophagojejunostomy is technically demanding and difficult in laparoscopic gastrectomy. Circular-stapled anastomosis is considered the "gold standard" method for oesophagojejunostomy in open total gastrectomy. A purse-string suture instrument is used to create a purse-string suture along the distal oesophagus as a standard technique for classic circular-stapled oesophagojejunostomy in the open total gastrectomy.
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