Trans-Cinnamaldehyde-Fighting Streptococcus mutans Using Nature.

Streptococcus mutans (S. mutans) is the main cariogenic bacterium with acidophilic properties, in part due to its acid-producing and -resistant properties. As a result of this activity, hard tooth structures may demineralize and form caries. Trans-cinnamaldehyde (TC) is a phytochemical from the cinnamon plant that has established antibacterial properties for Gram-positive and -negative bacteria. This research sought to assess the antibacterial and antibiofilm effects of trans-cinnamaldehyde on S. mutans. TC was diluted to a concentration range of 156.25-5000 µg/mL in dimethyl sulfoxide (DMSO) 0.03-1%, an organic solvent. Antibacterial activity was monitored by testing the range of TC concentrations on 24 h planktonic growth compared with untreated S. mutans. The subminimal bactericidal concentrations (MBCs) were used to evaluate the bacterial distribution and morphology in the biofilms. Our in vitro data established a TC MBC of 2500 µg/mL against planktonic S. mutans using a microplate spectrophotometer. Furthermore, the DMSO-only controls showed no antibacterial effect against planktonic S. mutans. Next, the sub-MBC doses exhibited antibiofilm action at TC doses of ≥625 µg/mL on hydroxyapatite discs, as demonstrated through biofilm analysis using spinning-disk confocal microscopy (SDCM) and high-resolution scanning electron microscopy (HR-SEM). Our findings show that TC possesses potent antibacterial and antibiofilm properties against S. mutans. Our data insinuate that the most effective sub-MBC of TC to bestow these activities is 625 µg/mL.

Number of consecutive procedures after endodontic treatment to extraction: A 28-year retrospective study.

STATEMENT OF PROBLEM: After endodontic treatment, teeth may require additional treatment. Data regarding the number of treatments up to extraction after endodontic treatment are lacking. PURPOSE: The purpose of this retrospective study was to evaluate the number of consecutive restorative procedures performed on a specific tooth starting from endodontic treatment up to extraction. A comparison was made between crowned and uncrowned teeth. MATERIAL AND METHODS: A retrospective study was conducted using 28 years of data from a private clinic. The total number of patients was 18 082 and included 88 388 treated teeth. The data were collected for permanent teeth that received at least 2 consecutive retreatments. The data included tooth number, procedure type, date of procedure, total number of procedures conducted during the study period, extraction date, time from endodontic treatment to extraction, and whether the tooth had been crowned or not. Endodontically treated teeth were divided into 2 groups: extracted and nonextracted. In each group, a comparison was made between crowned and uncrowned teeth and between anterior and posterior teeth by using the Student t test (α=.05). RESULTS: In the non extracted group, teeth that were crowned required significantly (P<.05) fewer restorative treatments (mean ±standard deviation 2.9 ±2.1) than uncrowned teeth (5.01 ±2.98). For extracted teeth, the mean time from endodontic treatment until extraction was 10.39 years. Crowned teeth were extracted after a mean of 11.06 years and 3.98 treatments, while uncrowned teeth were extracted after a mean of 9.96 years and 7.22 treatments (P<.05). CONCLUSIONS: Endodontically treated teeth that were crowned required significantly fewer subsequent restorative procedures than uncrowned teeth and exhibited higher survival rates up to extraction.

Guided Implant Placement in Fully Edentulous Patients. The Full Retraction Protocol: Registration Technique to Improve Treatment Outcome.

Preoperative planning and implant placement can be optimized using implant planning software followed by the creation of an individual surgical guide. Alongside clinical advantages of using guided surgery, a variability in the accuracy of implant position has been reported. This variability is even more substantial in fully edentulous patients and attributed to errors from intrinsic and extrinsic sources. The aim of this paper is to discuss the potential process errors and present two digital data registration protocols to be implemented in fully edentulous patients. The suggested protocols are aimed to improve accuracy of data acquisition, data superimposition on planning software, and therefore treatment outcome as well.

Next generation of dentists moving to amalgam-free dentistry: Survey of posterior restorations teaching in North America.

OBJECTIVES: The dental field is gradually reducing the use of amalgam and moving towards adhesive restoration. This change is in accordance with the advancement and improvement of composite resin materials and adhesion systems. Consequently, posterior cavity preparations teaching should be re-examined to determine whether dental schools are adapting their curriculum to fit the current trends in dentistry and what rationale supports their decisions. METHODS: An online questionnaire was constructed to assess the time dedicated to teaching composite materials and amalgam, in addition to the principles of posterior preparations, for composite restorations in North American dental schools. RESULTS: A total 33 schools responded to the questionnaire. A large variation was found in teaching methods and techniques of posterior restorations. The reasoning for teaching amalgam restorations was diverse as were the principles of composite resin preparation taught. CONCLUSION: No agreed principles of cavity preparation for resin composite restorations were found, as opposed to explicit agreement on amalgam cavity preparations. The results demonstrate a lack of clear guidelines for cavity preparation of resin composite restorations. Dental schools may benefit when a consensus on this topic is achieved.

Antibacterial Orthodontic Cements and Adhesives: A Possible Solution to Streptococcus mutans Outgrowth Adjacent to Orthodontic Appliances.

PURPOSE: To assess the antibacterial effect of orthodontic cements containing 1% insoluble antibacterial polycat-ionic nanoparticles against Streptococcus mutans. MATERIALS AND METHODS: Polycationic polyethyleneimine (PEI)-based nanoparticles were incorporated into GC Fuji Ortho LC (GC), CX-plus (Shofu) orthodontic cements and in Neobond Transbond plus (Denstply) and Transbond XT (3M) orthodontic adhesives. The samples were evaluated immediately after setting, as well as after two weeks and one month of aging. The antibacterial effect against S. mutans was evaluated with the direct contact test and the agar diffusion test. In addition, the antibacterial properties of the eluate from the examined materials was tested. Four-way ANOVA followed by Tukey's test was used to determine bacterial growth rates. RESULTS: S. mutans outgrowth was substantially reduced (p < 0.05) following direct contact with the surface of Neobond adhesives (95%, i.e. 5-6 log reduction) and GC Fuji Ortho LC cement samples (97% reduction) containing PEI nanoparticles. CX-plus cement, Transbond plus and Transbond XT adhesives with and without PEI showed no antibacterial effect, and S. mutans outgrowth was similar to that of the controls. CONCLUSIONS: Neobond adhesive and GC Fuji Ortho LC cement with 1% incorporated insoluble antibacterial polycat-ionic nanoparticles exhibited stable antibacterial properties, particularly after immediate contact between the cement and the adhesive, and thus may prevent S. mutans outgrowth adjacent to orthodontic appliances. Further studies are needed to evaluate the efficacy, physical properties and possible side effects of the PEI nanoparticles in vivo.

Antibacterial Effect of a Temporary Cement-Dissolving Liquid.

PURPOSE: Methods for removing temporary cement with an antibacterial effect might improve prosthetic treatment prognosis. MATERIALS AND METHODS: Three removal methods were assessed: (1) immersion of an acrylic provisional restoration in a temporary cement dissolver (Temp-off); (2) mechanical removal with a dental explorer; and (3) sandblasting. Two temporary cements, one with eugenol (Temp-Bond) and one without eugenol (Temp-Bond NE) and of two thicknesses (100 µm and 250 µm), were examined. RESULTS: Immersion in Temp-off produced the most effective bacterial count decrease compared to the other methods (P < .05). No significant difference was found between the two cement types, although the decrease in count was more evident in the thicker (250 µm) cement layer. CONCLUSION: Temp-off dissolving liquid used for removal of temporary cement exhibited an antibacterial effect and nonmechanical cleaning ability.

Antibacterial Activity of Orthodontic Cement Containing Quaternary Ammonium Polyethylenimine Nanoparticles Adjacent to Orthodontic Brackets.

Enamel demineralization is a common problem found in patients using orthodontic devices, such as orthodontic braces. It was found that Streptoccocus mutans growth increases adjacent to orthodontic devices, which may result in caries development. Incorporated antibacterial quaternary ammonium polyethylenimine (QPEI) nanoparticles were previously shown to be highly efficacious against various bacteria. Combining antibacterial materials in orthodontic cement may be advantageous to prevent bacterial outgrowth adjacent to orthodontic brackets. The aim was to evaluate the efficiency of orthodontic cement containing QPEI nanoparticles in reducing S. mutans and Lactobacillus casei outgrowth adjacent to orthodontic brackets. Orthodontic brackets were bonded to the buccal surfaces of extracted lower incisors. The antibacterial effect on S. mutans and L. casei outgrowth of Neobond bracket adhesive orthodontic cement with and without QPEI nanoparticles was compared. The antibacterial effect was evaluated using crystal violet staining and bacterial count (CFU/mL). The teeth in the experimental group, with the QPEI nanoparticles cement, showed significantly lower optical density (OD) values and CFU counts of S. mutans and L. casei than the teeth in the control group (p < 0.05). Based on the results, it can be concluded that orthodontic cement containing QPEI nanoparticles significantly inhibits S. mutans and L. casei growth around orthodontic brackets.