Determination of nicotine content in teeth submitted to prophylaxis and in-office bleaching by gas chromatography–mass spectrometry (GC-MS)

Clinical Oral Investigations

, Volume 22, Issue 9, pp 3043–3051 | Cite as

Abstract

Objectives

The objective of this study was to evaluate the dental color exposed to acute cigarette smoke treatment and quantify the amount of nicotine in samples exposed to cigarette smoke, after dental prophylaxis and after in-office bleaching.

Materials and methods

Sixty-nine healthy human molars were subjected to cigarette smoke in a cigarette machine. The teeth were divided into three groups: positive control, prophylaxis, and bleaching. Forty cycles of smoke exposition with duration of 15 min each were performed using 10 cigarettes (positive control). Dental prophylaxis was performed with a rotating brush and prophylaxis paste; in-office bleaching was performed with 35% hydrogen peroxide, in two sessions of three 15-min applications, with a 1-week interval between sessions. The color was evaluated at the baseline, after exposure to cigarette smoke, after dental prophylaxis, and after in-office bleaching. Teeth from each group were powdered and analyzed by gas chromatography–mass spectrometry in order to measure the amount of nicotine present in each group. Data from quantification of nicotine and color change were analyzed by one-way ANOVA and Tukey’s test (α = 0.05).
Data for subjective and objective color evaluation, a perceptible dental darkening occurred in teeth after exposure to cigarette smoke. Dental prophylaxis was able to recover the original color of teeth however, only after bleaching teeth became whiter than at the baseline (p < 0.001). The amount of nicotine was significantly different and higher in positive control group (3.3 ± 1.3 μg/g of tooth), followed by the prophylaxis group (2.1 ± 1.4 μg/g) and the bleaching group (0.8 ± 0.3 μg/g) (p < 0.001).

Conclusions

Cigarette smoke penetrates into the dental structure. Dental prophylaxis and bleaching with 35% hydrogen peroxide can partially remove the nicotine from tobacco smoke. However, when in-office bleaching was applied, a more significant nicotine removal was achieved.

Clinical significance

Dental prophylaxis could remove most of the external nicotine-staining on the tooth surfaces while bleaching could further reduce the external and internal nicotine-staining of teeth.
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A comparison between visual, intraoral scanner, and spectrophotometer shade matching: A clinical study

Abstract

Statement of problem

Visual shade matching is subjective and a cause of concern for clinicians. Different measurement devices have been developed to assist in tooth color selection and to achieve better esthetic results. However, consensus is lacking as to which method of tooth shade selection provides more predictable results.

Purpose

The purpose of this clinical study was to compare the reliability of different visual and instrumental methods for dental shade matching.

Material and methods

Visual shade matching was performed by 3 experienced clinicians using 2 different shade guides (VITA Classical A1-D4 and VITA Toothguide 3D-MASTER with 29 tabs; VITA Zahnfabrik) with and without the aid of a light-correcting device (Smile Lite; Smile Line). An intraoral scanner (TRIOS; 3Shape A/S) and a spectrophotometer (VITA Easyshade Advance 4.0; VITA Zahnfabrik) were also used for color shade matching. The instrumental methods were repeated 3 times to determine repeatability. Shade-matching sessions for each method were performed under controlled lighting on the middle third of the maxillary right central incisor of 28 participants. The Fleiss’ kappa statistical test was used to assess the reliability of each method. The weighted kappa statistical test was used to assess the agreement between the shades matched by different methods (α=.05).

Results

Instrumental methods were more accurate than visual methods. The best performance was found for the intraoral scanner configured for the 3D-MASTER scale (Fleiss’ kappa value of .874) and for the spectrophotometer configured for the VITA Classical scale (Fleiss’ kappa value of .805). The best visual shade-matching method was the VITA Classical scale associated with the light-correcting device (Fleiss’ kappa value of .322). The Classical scale without the light-correcting device showed the poorest reliability (Fleiss’ kappa value of .177) (P<.05).

Conclusions

Instrumental methods for color shade matching were more reliable than the visual methods tested.
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CAD/CAM implant crowns in a digital workflow: Five‐year follow‐up of a prospective clinical trial

Clinical Implant Dentistry and Related Research banner

ORIGINAL ARTICLE

Abstract

Background

Implant restorations became the first choice for single‐tooth replacement today.

Purpose

The prospective clinical trial aims to investigate computer‐aided‐design (CAD)/computer‐aided‐manufacturing (CAM)‐processed implant crowns after 5 years of loading.

Materials and Methods

Twenty patients were included for cement‐retained crowns in posterior sites. Radiographic analysis of bone levels was performed after delivery and follow‐up. The Functional Implant Prosthodontic Score (FIPS) was assessed at the final follow‐up. Wilcoxon signed‐rank tests were used with a level of significance set at α = 0.05.

Results

One implant was lost, resulting in a success rate of 95% at 5 years. For 19 crowns, neither technical complications nor biological complications were observed. The mean marginal bone level was 0.6 ± 0.26 mm (range: 0.18‐1.12) mesially, and 0.79 ± 0.36 mm (range: 0.23‐1.36) distally at 5 years. During the observation period, mean radiographic bone levels increased significantly by 0.23 mm at mesial and by 0.17 mm at distal sites (P < .0001) indicating minor additional bone loss. The mean total FIPS score was 8.2 ± 1.0 (range: 7‐10) with the high score of 2.0 ± 0.0 for the variable “bone.”

Conclusions

CAD/CAM‐processed implant crowns demonstrated promising radiographic and clinical outcomes after 5 years in function. Future large‐scale trials are crucial to confirm these initial results in the field of digital implant processing.

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Cone-beam Computed Tomography Compared with Intraoral Radiographic Lesions in Endodontic Outcome Studies: A Systematic Review

Highlights

  • This systematic review qualified and quantified CBCT in endodontic outcome.
  • Six articles met the inclusion criteria with low to moderate risk of bias. The certainty of evidence was high.
  • CBCT is twice as likely to detect a lesion compared to traditional radiography.

Abstract

Introduction

The purpose of this systematic review was to compare and quantify endodontic outcome using cone-beam computed tomographic (CBCT) imaging with intraoral periapical radiography.

Methods

Two reviewers independently conducted a comprehensive literature search. The MEDLINE, Embase, Cochrane, and PubMed databases were searched. Additionally, bibliographies, gray literature of all relevant articles, and textbooks were manually searched. There was no disagreement between the 2 reviewers.

Results

Six articles met the inclusion criteria with low to moderate risk of bias (good/fair quality). The certainty of evidence was moderate, indicating that the authors are moderately confident that the true effect lies close to that of the estimate of the effect as determined by Grading of Recommendations Assessment Development and Evaluation criteria. The odds ratio of CBCT imaging versus traditional imaging to detect a periapical lesion was 2.04 (95% confidence interval, 1.52–2.73).

Conclusions

Although intraoral radiographs are the imaging modality of choice, when 2-dimensional intraoral radiography is inconclusive, CBCT imaging was reported in this investigation to have twice the odds of detecting a periapical lesion than traditional periapical radiography in endodontic outcome studies.
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CAD/CAM produces dentures with improved fit

Clinical Oral Investigations

, Volume 22, Issue 8, pp 2829–2835 | Cite as

Original Article

First Online:

Abstract

Objectives

Resin polymerisation shrinkage reduces the congruence of the denture base with denture-bearing tissues and thereby decreases the retention of conventionally fabricated dentures. CAD/CAM denture manufacturing is a subtractive process, and polymerisation shrinkage is not an issue anymore. Therefore, CAD/CAM dentures are assumed to show a higher denture base congruence than conventionally fabricated dentures. It has been the aim of this study to test this hypothesis.

Materials and methods

CAD/CAM dentures provided by four different manufacturers (AvaDent, Merz Dental, Whole You, Wieland/Ivoclar) were generated from ten different master casts. Ten conventional dentures (pack and press, long-term heat polymerisation) made from the same master casts served as control group. The master casts and all denture bases were scanned and matched digitally. The absolute incongruences were measured using a 2-mm mesh.

Results

Conventionally fabricated dentures showed a mean deviation of 0.105 mm, SD = 0.019 from the master cast. All CAD/CAM dentures showed lower mean incongruences. From all CAD/CAM dentures, AvaDent Digital Dentures showed the highest congruence with the master cast surface with a mean deviation of 0.058 mm, SD = 0.005. Wieland Digital Dentures showed a mean deviation of 0.068 mm, SD = 0.005, Whole You Nexteeth prostheses showed a mean deviation of 0.074 mm, SD = 0.011 and Baltic Denture System prostheses showed a mean deviation of 0.086 mm, SD = 0.012.

Conclusions

CAD/CAM produces dentures with better fit than conventional dentures.

Clinical Relevance

The present study explains the clinically observed enhanced retention and lower traumatic ulcer-frequency in CAD/CAM dentures.
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