Assessment of enamel discoloration in vitro following exposure to cigarette smoke and emissions from novel vapor and tobacco heating products

 

Annette  Dalrymple, bsc (hon), phd,  Thomas  C.  Badrock,  Anya  Terry, bsc (hon), Mark  Barber, Peter  J.  Hall, bsc (hon), phd, David  Thorne, bsc (hon), msc, Marianna  D.  Gaca, bsc (hon), msc, phd, Steven  Coburn, bsc (hon), phd  &  Christopher  Proctor, bsc (hon), phd

 

Abstract: Purpose: To evaluate in vitro enamel sample discoloration following exposure to a scientific reference cigarette (3R4F) or emissions from next generation tobacco and nicotine products (NGPs) such as electronic cigarettes (EC) and tobacco heating products (THP). Methods: Bovine enamel blocks (6.5 × 6.5 mm) were prepared and pre-incubated with human or artificial saliva, to form a pellicle layer before exposure to either particulate matter (PM) or whole aerosols. PM was prepared by capturing 3R4F cigarette smoke (CS), a commercial THP (THP1.0) or a novel vapor product (NVP)/next generation e-cigarette aerosols on Cambridge filter pads followed by elution with dimethyl sulfoxide (DMSO). Ten enamel samples were exposed to each PM for 14 days. For aerosol exposure, 12 enamel samples were exposed (200 puffs per day, for 5 consecutive days) to 3R4F CS or THP1.0 and NVP aerosols. Control samples were incubated with DMSO (PM study) or phosphate buffered saline (PBS, aerosol study). Individual enamel sample color readings (L*, a*, b*) were measured at baseline and on each exposure day. Mean ΔL*, Δa*, Δb* and ΔE values were calculated for each product or control. A one-way ANOVA was used to assess the differences between the products and controls. The Tukey procedure for pairwise comparisons was also used. Results: At all timepoints, 3R4F PM and CS induced enamel discoloration that was statistically significant (P< 0.0001) when compared to THP1.0 or NVP. After 14-day PM exposure, mean ΔE values were 29.4 ± 3.6, 10.5 ± 2.3, 10.7 ± 2.6 and 12.6 ± 2.0 for 3R4F, THP1.0, NVP and DMSO control respectively. After 5-day CS or aerosol exposure, mean ΔE values were 26.2 ± 3.2, 3.6 ± 1.9, 3.4 ± 1.3, 5.3 ± 0.8 for 3R4F CS, THP1.0, NVP or PBS control, respectively. Both exposure methods demonstrated that THP1.0 and NVP induced minimal staining, mean ΔL*, Δa*, Δb* and ΔE values were comparable to DMSO or PBS controls. (Am J Dent 2018;31:227-233).

 

 

 

Mail: Annette Dalrymple, British American Tobacco, R&D, Southampton, SO15 8TL, UK. E-mail: annette_dalrymple@bat.com

 

 

Bacterial leakage in external hexagon implants with and without the interposition of a sealing-connector

 

Rosario Rizzo, dds, Domenico Tripodi, md, dds, Flavia Iaculli, dds, phd, Adriano Piattelli, md, dds, Giovanna Iezzi, dds, phd, Vittoria Perrotti, dds, phd  &  Simonetta D’Ercole, dds, phd

 

Abstract: Purpose: To investigate whether the interposition of a sealing-connector was able to reduce the bacterial leakage in external hexagon implants. Methods: 20 implants with external hexagon connection were used. Ten Test implant-abutment assemblies were connected with the interposition of a sealing-connector molded in the exact shape of the two opposed surfaces. Ten Control implant-abutment assemblies were connected with no sealing-connector interposed. Two types of bacteria were introduced into the internal portion of the implant, before placing the connector. The study lasted 28 days. Results: All control specimens, seeded with P. aeruginosa (PA) and A. actynomycetemcomitans (AA), showed contamination of the culture medium, indicative of microbial leakage. In the Test specimens, three instances of contaminated specimens were found in the samples seeded with PA and two contaminated specimens in the ones seeded with AA, for a total of five contaminated samples out of 10. The use of the sealing-connector was able to prevent bacterial leakage in half of the samples (50%). The leakage in both groups occurred mainly in the last week of the experiment. Probably, a longer period, under the conditions of this experiment, is necessary for the migration of the bacteria, and, furthermore, an observation period of 7 or 14 days may not be enough to show microbial contamination. (Am J Dent 2018;31:234-238).

 

 

Mail: Dr. Vittoria Perrotti, Via dei Vestini 31, 66100 Chieti, Italy. E-mail: v.perrotti@unich.it

 

 

Clinical evaluation of two in-office dental bleaching agents

 

Renata Vasconcelos Monteiro, dds, ms, phd, Sylvio Monteiro Junior, dds, ms, phd &  Mauro Amaral Caldeira de Andrada, dds, ms, phd

 

Abstract: Purpose: To evaluate the bleaching efficacy and time required for color stability immediately after dental office bleaching. Methods:  40 subjects were randomly divided into two groups, according to the bleaching agent used: G_HP – 35% hydrogen peroxide gel and G_CP – 37% carbamide peroxide gel. The color was measured with a spectro-photometer before and immediately, 24 hours, 72 hours, 7 days and 15 days after the bleaching procedure. The color parameters were evaluated and the ΔE*, ΔL*, Δa* and Δb* values were calculated for each evaluation period. The data was statistically analyzed with Student’s T-test, one-way ANOVA and Tukey’s post hoc test (P ≤ 0.05). Results: Regarding the ΔE* values, in the assessed periods there were no significant differences between groups (P≥ 0.05). However, the luminosity (ΔL*) decreased considerably in both groups in the first 72 hours (P≤ 0.05), followed by an increase at 15 days (P≤ 0.05) in the hydrogen peroxide group. Regarding the Δb* values, the G_HP showed higher negative alterations in the b* axis in the first 24 hours. The 37% carbamide peroxide gel and the 35% hydrogen peroxide gel were effective and there was no reversal of tooth color within 15 days; however a more accentuated bleaching effect was observed immediately after bleaching. (Am J Dent 2018;31:239-242).

 

 

 

Mail: Dr. Renata Vasconcelos Monteiro, Deputado Antonio Edu Vieira, Street 516/401B- Pantanal - 88040-001 - Florianopolis, SC, Brazil.  E-mail: renata_vm_@hotmail.com

 

 

Non-invasive proximal adhesive restoration of natural non-cavitated proximal lesions

 

Marwa Abdelaziz, dr med dent, PhD , Adele Lodi-Rizzini, dr med dent, Tissiana Bortolotto, dr med dent, phd,PD, Franklin Garcia-Godoy, dds, ms, phd, phd, Albert Joseph Feilzer, dds, phd  &  Ivo Krejci, dr med dent

 

 

 

 

 

 

 

 

Abstract: Purpose: To investigate the infiltration potential of different self-etch adhesives into natural non-cavitated proximal lesions and the effect of dehydration protocol on the infiltration of a self-etch adhesive. Methods: 29 extracted molars and premolars with natural proximal lesions (ICDAS 1-2) were sectioned through the lesion providing two samples from each lesion. To compare the different adhesives, three groups of eight lesions were abraded with fine metallic strips and then etched with 37% H₃PO₄ acid for 120 seconds. All teeth were stained with rhodamine isothiocyanate. After drying with compressed air and ethanol application, lesions were infiltrated with Scotchbond Universal, Clearfil SE Protect or OneCoat 7 Universal for 180 seconds and then coated with a thin layer of flowable composite (Tetric Flow). To compare the effect of dehydration protocol on infiltration, two groups of nine paired lesions were pretreated as described above. One group was dried using compressed air alone and the second group was dried using compressed air and ethanol, both groups were then infiltrated with Scotchbond Universal then coated with a thin film of flowable composite. After light curing, un-encapsulated dye was bleached by immersion in hydrogen peroxide. Remaining lesion pores were stained with sodium fluorescein solution. Thin cuts of the teeth were observed with confocal microscopy and computer image analysis was performed (ImageJ). Results: ANOVA and Duncan post-hoc tests showed no significant differences of the infiltrated area between the three adhesives (P= 0.835), no significant difference was found between the group dried with air compared to the one dried with air and ethanol. It can be concluded that the tested adhesives may be used for infiltration of natural lesions following the described pretreatment. (Am J Dent 2018;31:243-248).

 

 

 

Mail: Dr. Marwa Abdelaziz, Division of Cariology and Endodontology, University of Geneva, rue Michel-Servet 1, 1211 Geneva 4, Switzerland. E-mail: marwa.abdel@unige.ch

 

 

Novel ceramic primer vs. conventional treatment methods: Effects on roughness and bond strength of all-ceramic restorations

 

Mustafa Borga Dönmez, dds,  Munir Tolga Yucel, dds, phd, Ismail Kilic, dds, phd & Yener Okutan, dds, phd

 

Abstract: Purpose: To compare the influence of various surface treatments on the shear bond strength and surface roughness of lithium disilicate glass-ceramics. Methods: 60 lithium disilicate ceramic samples were prepared according to the manufacturers’ instructions and were divided into six groups according to the surface treatment: Control (C), 5% HF etching for 20 and 60 seconds (E20, E60), Monobond Etch & Prime etching (MEP), Nd:YAG (ND) and Er:YAG (ER) laser irradiation. All groups were treated with a universal primer except group MEP. A self-adhesive resin cement was bonded to all groups. The shear bond strengths of the specimens were measured using a universal testing machine while surface roughness was measured using a profilometer. Results: Kruskal-Wallis and Mann-Whitney U tests revealed significant differences (P< 0.05). The shear bond strength of group E60 was higher than the other groups while surface roughness of groups MEP and ER were highest. (Am J Dent 2018;31:249-252).

 

 

 

Mail: Dr. Mustafa Borga Dönmez, Department of Prosthodontics, Faculty of Dentistry, Selcuk University, Konya, Turkey. E-mail: borgadonmez@gmail.com

 

 

Non-invasive proximal adhesive restoration (NIPAR) compared to resin infiltration for treating initial proximal carious lesions

 

Marwa Abdelaziz, dr med dent, phd, Adele Lodi-Rizzini, dr med dent, Tissiana Bortolotto, dr med dent, phd, PD, Franklin Garcia-Godoy, dds, ms, phd, phd, Albert Joseph Feilzer, dds, phd  &  Ivo Krejci, dr med dent

 

Abstract: Purpose: To compare a new technique of non-invasive proximal adhesive restoration (NIPAR) to the infiltration concept technique (ICON). Methods: Extracted human posterior teeth with non-cavitated proximal carious lesions (ICDAS code 1-2) were cut vertically to obtain two symmetrical lesions. Group 1 (NIPAR): Half of the paired lesions surfaces (n=13) were abraded with metallic strips and etched with 37% H₃PO₄ for 120 seconds. Group 2 (ICON): The other half of the paired lesions’ surfaces (n=13) were etched with 15% HCl gel for 120 seconds. All samples were then stained with rhodamine isothiocyanate (RITC). After ethanol drying and isolation of the cut surface, Group 1 samples were infiltrated with Scotchbond Universal for 180 seconds and coated with a thin film of Tetric flow. Group 2 samples were infiltrated with ICON infiltrant following manufacturer’s instructions. After light curing, unbound rhodamine was bleached by immersion in 30% hydrogen peroxide for 12 hours. Remaining lesion pores were stained with sodium fluorescein solution. Samples were observed with confocal microscopy (CLSM) and the percentage of infiltration (area of resin infiltration/area of total demineralization ×100) was calculated using ImageJ. Results: 11 samples out of 13 showed larger infiltrated area of the lesions in Group 1 (NIPAR) compared to Group 2 (ICON). Statistical analysis revealed a significant difference between the two groups (P< 0.05). Within the limitations of this study, NIPAR allowed for better infiltration of non-cavitated proximal carious lesions when compared to ICON. (Am J Dent 2018;31:255-260).

 

 

Mail: Dr. Marwa Abdelaziz, Division of Cariology and Endodontology, University of Geneva, rue Michel-Servet 1, 1211 Geneva 4, Switzerland. E-mail: marwa.abdel@unige.ch

 

Patient- and treatment-related factors may influence the longevity of primary teeth restorations in high caries-risk children: A university-based retrospective study

 

Débora Martini Dalpian, dds, ms, phd,  Caroline Sala Gallina, dds,  Gabriel Ferreira Nicoloso, dds, ms, phd, Marcos Britto Correa, dds, ms, phd,  Franklin Garcia-Godoy, dds, ms, phd, phd, Fernando Borba de Araujo, dds, ms, phd  &   Luciano Casagrande, dds, ms, phd

 

Abstract: Purpose: To evaluate the longevity and factors associated with failure of primary teeth restorations placed in high caries-risk children. Methods: The sample was comprised of children treated in a University Dental Service. Patients records were screened retrospectively to determine whether they had received restorative treatment in primary teeth presenting cavitated caries lesions. Kaplan-Meier estimator and Multivariate Cox regression analysis with shared frailty were used to assess restorations’ survival and factors associated with failure, respectively. Results: 123 high caries-risk children (10.3±4 DMF-T) with 316 restorations were analyzed. The 3-year survival reached 53.4% (AFR=18.8%). Restorations placed without rubber dam (P= 0.04), over selective caries removal (P= 0.03), with calcium hydroxide liner (P< 0.01) and glass-ionomer cement (P= 0.04) presented lower survival rates. Caries-controlled patients presented significantly (P= 0.03) higher rates of restoration survival (77.7%) than caries-active patients (49.9%). The adjusted model showed that restorations placed in teeth after selective caries removal showed 3.41 times higher risk of failure compared with restorations over complete caries removal (95%CI:1.37-8.46). (Am J Dent 2018;31:261-266).

 

 

 

 

Mail: Dr. Luciano Casagrande, Department of Oral Surgery and Orthopedics, Pediatric Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos 2492, Bom Fim, Porto Alegre, RS 90.035-003, Brazil. E-mail: luciano.casagrande@ufrgs.br; luciano.casagrande@gmail.com

 

 

Effectiveness of low-level diode laser therapy on pain during cavity preparation on permanent teeth

 

Felice Femiano, md, phd,  Rossella Femiano, dds, Luigi Femiano, dds, Giuliano Aresu, Vincenzo Maria Festa, dds, Rosario Rullo, md  &  Letizia Perillo, md

 

Abstract: Purpose: To evaluate the effectiveness of low-level laser therapy (LLLT) on dental pain felt during cavity preparation of carious lesions in permanent teeth of adults. Methods: The study was carried out on 88 teeth with dental caries requiring class I restorations in 24 subjects with a pain score ≥ 7 but < 10 measured using a 0-10 visual analogue scale (VAS) in a preliminary test of pain threshold (PTPT) for each subject receiving a class I cavity preparation on another tooth without local anesthesia. The 88 teeth included were randomly allocated to test and control groups, each with 44 teeth. All teeth were treated with LLLT prior to the mechanical preparation of the cavity without local anesthesia, except that the laser device was kept in idle mode in the control group. After cavity preparation, subjects scored pain intensity using the VAS. The Wilcoxon test was used to analyze data and the values with P< 0.05 were considered significant. Results: All subjects scored a pain reduction in the test group compared with the control group (P< 0.0001), with a reduction of 42% and 16%, respectively, compared to pain felt during the PTPT. The use of LLLT prior to mechanical preparation of a cavity by lowering pain intensity might reduce the quantity of drugs used for pain control required during restorative procedures. (Am J Dent 2018;31:267-271).

 

 

 

 

Mail: Prof. Felice Femiano, Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Study of Campania, Luigi Vanvitelli, Ex SUN, Via De Crecchio 6, Naples, Italy. E-mail: femiano@libero.it

 

 

The ability of marginal detection using different intraoral scanning systems: A pilot randomized controlled trial

 

Marco Ferrari, md, dmd, phd, Andrew Keeling, bds, phd, bsc (hons), Federico Mandelli, dds, Giuseppe Lo Giudice, md, dds, Franklin Garcia-Godoy, dds, ms, phd, phd  &  Tim Joda, pd, dr med dent, dmd, msc

 

Abstract: Purpose: To assess the clinical ability of marginal detection of different intraoral optical scanning (IOS) systems. Methods: The Ethics Committee of the University of Siena, Italy approved the research project. Thirty patients in need of an onlay/inlay with supra-gingival margins were included and randomly divided in three groups of 10 (3× n=10) according to the IOS for chairside capturing: (A) GC-Europe (Aadva); (B) True-Definition-TD; (C) Trios. A total of 1 scans from each IOS test group (A-C), were obtained clinically and stored as STL-files. In addition, corresponding conventional impressions were taken for all 30 patients, poured with stone, and then processed by a laboratory scanner (Aadva), serving as controls. All 60 STL-files were imported to the Exocad platform for analysis. The horizontal distance between each preparation margin and the adjacent tooth was measured using the ruler tool in the software. The distance at which the detection of the margin started to become visibly unclear was recorded for the horizontal distances. Data was processed statistically by one-way ANOVA (P> 0.05). Results: No statistically significant inter-test group differences could be identified (IOS A-C). The minimum distance from which a clear margin was visible, was 4.5 (SD 0.1) mm for all images, regardless of which IOS was used. Under these experimental clinical conditions, all tested IOS performed similarly. In contrast, all margins of the controls were clearly visible. (Am J Dent 2018;31:272-276).

 

 

Mail: Prof. Marco Ferrari, Policlinico Le Scotte, Viale Bracci 1, Siena 53100,  Italy.  E-mail: ferrarm@gmail.com