^{April 2015 Abstracts}

Gingival crevicular blood as a source to screen for diabetes control

in a dental office setting

 

Jung-Wan M. Kim, dds, ms, Ryan E. Wolff, dds, ms, Philippe Gaillard, phd  &  Larry F. Wolff, ms, phd, dds

 

Abstract: Purpose: To determine if gingival crevicular blood (GCB) could potentially be used as a reliable source to screen for diabetes control, this study compared glycosylated hemoglobin (HbA1c) levels found in GCB and serum. Methods: Patients diagnosed (n= 29), with diabetes received a venipuncture on the finger and serum blood (control) obtained was tested for HbA1c status chair-side. GCB (test) was collected at site(s) with evidence of bleeding after probing and the HbA1c value was determined in the same manner as with the serum blood. Results: There was a significant correlation between serum blood and GCB using the HbA1c test. The Pearson correlation was 0.98 (P< 0.0001). The Altman-Bland bias was -0.21 (P= 0.0095), indicating that on average, the GCB method slightly underestimated the venipuncture serum (control) method for determining HbA1c values. The Altman-Bland 95% agreement interval ranged from -1.02 to 0.6. Furthermore, the HbA1c values were independent of the gingival sites used for collection with intra-patient GCB values exhibiting a correlation value between sites of 0.91 (P< 0.0001). (Am J Dent 2015;28:63-67).

 

 

 

 

Mail: Dr. Larry F. Wolff, Division of Periodontics, Department of Developmental and Surgical Sciences University of Minnesota School of Dentistry, 515 Delaware St, SE Minneapolis, MN 55455, USA. E-mail:  wolff001@umn.edu

 

 

Comparing three toothpastes in controlling plaque and gingivitis:

A 6-month clinical study

 

Terdphong Triratana, dds, Petcharat Kraivaphan, dds, Cholticha Amornchat, dds, Luis R. Mateo, ma, Boyce M. Morrison, Jr., phd, Serge Dibart, dmd  &  Yun-Po Zhang, phd, dds (hon)

 

Abstract: Purpose: To investigate the clinical efficacy of three toothpastes in controlling established gingivitis and plaque over 6 months. Methods: 135 subjects were enrolled in a single-center, double-blind, parallel group, randomized clinical study. Subjects were randomly assigned to one of three treatments: triclosan/copolymer/fluoride dentifrice containing 0.3% triclosan, 2.0% copolymer and 1,450 ppm F as sodium fluoride in a silica base; herbal/bicarbonate dentifrice containing herbal extract and 1,400 ppm F as sodium fluoride in a sodium bicarbonate base; or fluoride dentifrice containing 450 ppm F as sodium fluoride, and 1,000 ppm F as sodium monofluorophosphate. Subjects were instructed to brush their teeth twice daily for 1 minute for 6 months. Results: After 6 months, subjects assigned to the triclosan/copolymer/fluoride group exhibited statistically significant reductions in gingival index scores and plaque index scores as compared to subjects assigned to the herbal/bicarbonate group by 35.4% and 48.9%, respectively. There were no statistically significant differences in gingival index and plaque index between subjects in the herbal/ bicarbonate group and those in the fluoride group. The triclosan/copolymer/fluoride dentifrice was statistically significantly more effective in reducing gingivitis and dental plaque than the herbal/bicarbonate dentifrice, and this difference in efficacy was clinically meaningful. (Am J Dent 2015;28:68-74).

 

 

Mail: Dr. Yun-Po Zhang, Colgate-Palmolive, 909 River Road, Piscataway, NJ  08854, USA. E-mail: yun_po_zhang@colpal.com

 

 

Laser-induced fluorescence in the diagnosis of pulp exposure and the influence of residual dentin thickness: An in vivo study

 

Camilo  Abalos, dds, md, phd,  Manuela  Herrera, dds, md, phd,  Victoria  Bonilla, dds, phd,

Laura  San  Martin, dds, md, phd, mdphc  &  Asuncion  Mendoza, dds, md, phd

 

Abstract: Purpose: To clinically (a) determine whether laser-induced fluorescence (LIF) was able to assess pulp tissue health or disease in situations of pulp exposure; (b) evaluate the influence of different pulp tissue conditions upon LIF through dentin thicknesses of ≤ 1 mm ; and (c) explore possible differences between the diagnostic performance of quantitative (q) and qualitative (ql) LIF. Methods: 98 healthy subjects were scheduled for the treatment of caries. Three groups were established according to pulp tissue condition: Group A (n=30 teeth) (deep caries with healthy pulp tissue); Group B (n=30 teeth) (pulp necrosis); and Group C (n=30 teeth) (irreversible symptomatic acute pulpitis). The carious lesions were eliminated, and q and ql LIF measurements were made at two levels: measurement in dentin at < 1 mm from the pulp (A-D); and direct pulp exposure measurement (A-LP). In healthy pulp tissue at level A-LP, eight teeth with accidental pulp exposure were used. The Kruskal-Wallis test was used to evaluate the statistical significance of the differences in LIF readings among the three groups. The diagnostic performance of q and ql LIF in application to pulp tissue health or disease was assessed by calculating the sensitivity and specificity of the two tests at level A-LP. Results: A significant correlation was observed between acute pulpitis and an increase in the q LIF values at level A-D (P= 0.004), but with no correlation to healthy pulp. Quantitative and qualitative LIF may be useful in diagnosing pulp tissue health or disease in situations of pulp exposure (A-LP). (Am J Dent 2015;28:75-80).

 

 

 

 

Mail: Dr. Camilo Abalos, Faculty of Dentistry, University of Seville, C/ Avicena s/n, 41009 – Seville, Spain. E-mail: cabalos@us.es

 

 

Efficacy of a solar-powered TiO₂ semiconductor electric toothbrush on P. gingivalis biofilm

 

Takenori  Sato, dds, phd,  Naoki  Hirai, dds,  Yasuhiro  Oishi, dds, phd,  Gerry  Uswak, dmd, mph,

Kunio  Komiyama, dds, phd  &  Nobushiro  Hamada, dds, phd

 

Abstract: Purpose: To determine the efficacy of a solar-powered TiO₂ semiconductor electric toothbrush on Porphyromonas gingivalis biofilm. Methods: P. gingivalis cells were cultivated on sterilized coverslips under anaerobic conditions and were used as a biofilm. To evaluate the efficacy of the solar-powered TiO₂ electric toothbrush on the P. gingivalis biofilm, the bacterial cell biofilm coverslips were placed into sterilized phosphate buffered saline (PBS) and brushed for 1 minute. Following mechanical brushing, the coverslips were stained with 1% crystal violet (CV) for 10 seconds at room temperature. The efficacy of P. gingivalis biofilm removal by the solar-powered TiO₂ electric toothbrush was measured through the absorbance of the CV-stained solution containing the removed biofilm at 595 nm. The antimicrobial effect of the solar-powered TiO₂ semiconductor was evaluated by the P. gingivalis bacterial count in PBS by blacklight irradiation for 0 to 60 minutes at a distance of 7 cm. The electrical current though the solar-powered TiO₂ semiconductor was measured by a digital multimeter. The biofilm removal by the solar-powered TiO₂ semiconductor was also evaluated by scanning electron microscopy (SEM). Results: The biofilm removal rate of the solar-powered TiO₂ electric toothbrush was 90.1 ± 1.4%, which was 1.3-fold greater than that of non-solar-powered electric toothbrushes. The solar-powered TiO₂ semiconductor significantly decreased P. gingivalis cells and biofilm microbial activity in a time-dependent manner (P< 0.01). The electrical current passing through the solar-powered TiO₂ semiconductor was 70.5 ± 0.1 µA, which was a 27-fold higher intensity than the non-solar-powered brush. SEM analysis revealed that the solar-powered TiO₂ semiconductor caused a biofilm disruption and that cytoplasmic contents were released from the microbial cells. (Am J Dent 2015;28:81-84).

 

 

 

 

 

 

 

Mail: Dr. Nobushiro Hamada, Department of Microbiology, Kanagawa Dental University, 82 Inaoka-cho, Yokosuka 238-8580, Japan. E-mail: hamada@kdu.ac.jp

 

 

Effect of different prosthetic abutments on peri-implant soft tissue.

A randomized controlled clinical trial

 

Marco Ferrari, md, dmd, phd, Maria Crysanti Cagidiaco, md, dmd, phd, Franklin Garcia-Godoy, dds, ms, phd, phd, Cecilia Goracci, dds, ms, phd  &  Francesco Cairo, dds, ms

 

Abstract: Purpose: This randomized clinical trial assessed the effect of three different prosthetic abutments (titanium, gold-hue titanium and zirconia) on peri-implant soft tissue 2 years after treatment in partially edentulous subjects. Methods: Baseline data concerning (1) thickness of the buccal peri-implant soft tissue, (2) soft tissue thickness above the bone crest, (3) depth/length of transmucosal pathway, and (4) periodontal biotype at adjacent teeth were collected. The final sample consisted of 47 subjects (21 males, 26 females) with a total of 97 implants. A two-level (patient, implant) statistical model was applied. Results: At the 2-year clinical observation, recession of the gingival margin was observed only at 13% of implants irrespective of the type of abutment. No significant correlation between periodontal biotype at adjacent teeth and peri-implant biotype was observed. Furthermore, none of the investigated variables at patient level (age, gender, implant type, periodontal biotype) or at implant level (keratinized tissue thickness, probing depth, soft tissue thickness) was identified as a significant predictor of recession. In conclusion, this study pointed out that (1) abutment type was not able to influence peri-implant variables after 2 years, and (2) caution should be used in considering periodontal biotype at patient level as a possible indicator of the future peri-implant biotype. (Am J Dent 2015;28:85-89).

 

 

Mail:  Prof. Dr. Marco Ferrari, Department of Medical Biotechnology, University of Siena, Viale Bracci 1, Siena 53100, Italy.  E-mail:  ferrarm@gmail.com

 

 

Dentin tubule occluding ability of dentin desensitizers

 

Linlin Han, dds, phd  &  Takashi Okiji, dds, phd

 

Abstract: Purpose: To compare the dentin tubule-occluding ability of fluoroaluminocalciumsilicate-based (Nanoseal), calcium phosphate-based (Teethmate Desensitizer), resin-containing oxalate (MS Coat ONE) and diamine silver fluoride (Saforide) dentin desensitizers using artificially demineralized bovine dentin. Methods: Simulated hypersensitive dentin was created using cervical dentin sections derived from bovine incisors using phosphoric acid etching followed by polishing with a paste containing hydroxyapatite. The test desensitizers were applied in one, two, or three cycles, where each cycle involved desensitizer application, brushing, and immersion in artificial saliva (n= 5 each). The dentin surfaces were examined with scanning electron microscopy, and the dentin tubule occlusion rate was calculated. The elemental composition of the deposits was analyzed with electron probe microanalysis. Data were analyzed by one-way ANOVA and the Tukey honestly significant different test. Results: Marked deposit formation was observed on the specimens treated with Nanoseal or Teethmate Desensitizer, and tags were detected in the specimens’ dentin tubules. These findings became more prominent as the number of application cycles increased. The major elemental components of the tags were Ca, F, and Al (Nanoseal) and Ca and P (Teethmate Desensitizer). The tubule occlusion rates of MS Coat ONE and Saforide were significantly lower than those of Nanoseal and Teethmate Desensitizer (P< 0.05). (Am J Dent 2015;28:90-94).

 

 

 

Mail: Dr. Linlin Han, Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, 5274 Gakkocho-dori 2-bancho, Chuo-ku, Niigata 951-8514, Japan. E-mail: han@dent.niigata-u.ac.jp

 

 

 

Influence of CAD-CAM diamond bur deterioration on surface roughness and maximum failure load of Y-TZP-based restorations

 

Pedro Henrique Corazza, dds, ms, phd, Humberto Lago de Castro, dds, msc, phd, Sabrina Alves Feitosa, dds, msc, phd, EstevÃo Tomomitsu Kimpara, dds, ms, phd  &  Alvaro Della Bona, dds, mmedsci, phd

 

Abstract: Purpose: To investigate the influence of CAD-CAM diamond bur deterioration on surface roughness (Ra) and maximum failure load (Lf) of Y-TZP-based ceramic (YZ) substructures (SB) veneered with a feldspathic porcelain. Methods: Two sets of burs (B1 and B2) were used to fabricate 30 YZ SB each in a CAD/CAM system (Cerec InLab). The SB were identified (1-30) according to the milling sequence (MS). SEM images of the burs were recorded before milling, and after milling 15 and 30 SB. The SB Ra was measured. All SB were veneered, cemented onto a fiber reinforced epoxy resin die, and loaded to failure. Specimens from B1 group were cyclic fatigued (106 cycles) before loading to failure. Fractographic analysis was performed. Data were statistically analyzed using Student’s t-test, Weibull analysis, Pearson’s correlation and ANOVA (α= 0.05). Results: The mean Ra value of B1 specimens was statistically greater than B2. Weibull modulus of B1 and B2 were statistically similar. The correlation between MS and Lf was not statistically significant for the groups. MS and Ra had significant correlation for both groups (B1: r= -0.514, P= 0.015; B2: r= -0.462, P= 0.03). Although the visual aspect (SEM) of the burs was similar after 30 millings, the mean Ra values were significantly different after 27 millings for B1 and 24 millings for B2. (Am J Dent 2015;28:95-99).

 

 

 

 

 

 

Mail: Dr. Alvaro Della Bona, Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, BR 285, Passo Fundo,  99001-970  Brazil. E-mail: dbona@upf.br

 

 

The effect of antacid on salivary pH in patients with and without dental erosion after multiple acid challenges

 

Sarah  Dhuhair, bds, ms,  Joseph  B.  Dennison, dds, ms, ms, Peter Yaman, dds, ms  & Gisele F. Neiva, dds, ms, ms

 

Abstract: Purpose: To evaluate the effect of antacid swish in the salivary pH values and to monitor the pH changes in subjects with and without dental erosion after multiple acid challenge tests. Methods: 20 subjects with tooth erosion were matched in age and gender with 20 healthy controls according to specific inclusion/exclusion criteria. Baseline measures were taken of salivary pH, buffering capacity and salivary flow rate using the Saliva Check System. Subjects swished with Diet Pepsi three times at 10-minute intervals. Changes in pH were monitored using a digital pH meter at 0-, 5-, and 10-minute intervals and at every 5 minutes after the third swish until pH resumed baseline value or 45 minutes relapse. Swishing regimen was repeated on a second visit, followed by swishing with sugar-free liquid antacid (Mylanta Supreme). Recovery times were also recorded. Data was analyzed using independent t-tests, repeated measures ANOVA, and Fisher’s exact test (α= 0.05). Results: Baseline buffering capacity and flow rate were not significantly different between groups (P= 0.542; P= 0.2831, respectively). Baseline salivary pH values were similar between groups (P= 0.721). No significant differences in salivary pH values were found between erosion and non-erosion groups in response to multiple acid challenges (P= 0.695) or antacid neutralization (P= 0.861). Analysis of salivary pH recovery time revealed no significant differences between groups after acid challenges (P= 0.091) or after the use of antacid (P= 0.118). There was a highly significant difference in the survival curves of the two groups on Day 2, with the non-erosion group resolving significantly faster than the erosion group (P= 0.0086). (Am J Dent 2015;28:100-104).

 

 

 

Mail: Dr. Gisele F. Neiva, Department of Cariology, Restorative Sciences and Endodontics, University of Michigan, 1011 N. University, Ann Arbor, MI 48109-1078, USA. E-mail: gisele@umich.edu

 

 

Influence of heat and ultrasonic treatments on the setting and maturation

of a glass-ionomer cement

 

Marion Dehurtevent, dds, Etienne Deveaux, dds, phd, Jean Christophe Hornez, phd, Lieven Robberecht, dds, Nicolas Tabary, phd  &  Feng Chai, dds, phd

 

Abstract: Purpose: To compare the effect of different treatments (heat capsule, ultrasound, and dual treatments) on the setting kinetics and maturation properties of a conventional GIC (EQUIA, GC) to that of standard setting. Methods: The optimal durations of the heat and ultrasonic treatments were determined by monitoring changes in the COO^-/COOH ratio, surface hardness, and temperature within the samples. The influence of optimal treatments on the maturation properties of the GIC (microhardness, and 3-point flexural strength) were assessed using GIC samples incubated in artificial saliva for 24 hours, 1 month, and 3 months. Results: The optimal durations of the heat and ultrasonic treatments for accelerating setting were 5 minutes and 35 seconds, respectively. The dual treatment using the optimal conditions of the individual treatments further enhanced the setting kinetics. A temperature peak (49°C) within the GIC was detected during setting. Only the dual treatment increased the mechanical properties of the GIC after 24 hours compared to the control, while no significant difference was observed after 1 and 3 months. (Am J Dent 2015;28:105-110).

 

 

 

 

 

 

Mail: Dr. Marion Dehurtevent; Dr. Feng Chai, INSERM U1008, Groupe Recherche Biomatériaux, 1 Place de Verdun, Université Lille 2, 59045 Lille, France. E-mail: marion.dehurtevent@ univ-lille2.fr, fchai@univ-lille2.fr

 

 

Sol-gel-derived bioactive glasses demonstrate antimicrobial effects

on common oral bacteria

 

Satin  Salehi, phd,  Harry  B.  Davis, phd,  Jack  L.  Ferracane, phd   &  John  C.  Mitchell, phd

 

Abstract: Purpose: To determine the antibacterial effect of nano-structured, sol-gel processed bioactive glasses that may be used for implants, coatings, and as adjuncts to dental restorative materials. Methods: Six bioactive glasses (BAG), three made with differing amounts of silica (65, 75 and 85 mole%), and three with different amounts of silica (61, 71, and 81 mole%) and 3 mole% fluoride were prepared by a sol-gel synthesis method and tested against clinically important bacteria species, Streptococcus sobrinus (ATCC33478), Streptococcus mutans (ATCC25175) and Enterococcus faecalis(ATCC19433). Bacterial suspensions were independently incubated with bioactive glass in particulate form (< 3 µm) for 4 and 24 hours. Viability was determined by colony-forming units. Results: At 4 hours, all BAG produced an order of magnitude reduction in all three bacteria. After 24 hours, all BAG produced a significant reduction in S. sobrinus colonies, but no further reduction in S. mutans; all BAG, except BAG 61-F, significantly reduced E. faecalis compared to the control. At 4 hours, an increase in the pH of the BAG groups (to pH 9) could also have contributed to the bactericidal effect. In further experiments it was found that the viability of S. sobrinus was significantly reduced following exposure to an extract of BAG in media adjusted to a pH of 7.4. Additionally media with pH adjusted to 9 exerted a significant antibacterial effect against S. sobrinusafter 4 hours. To determine the influence of the calcium ions released from the BAG in the absence of the pH effect, a typical dose response was demonstrated after 4 hours of exposure of S. sobrinus to media containing various levels of calcium. The results of this study clearly suggest that the effect of BAG extract on bacteria is not only related to a pH effect, but is also linked to an effect of liberated ions, such as calcium, extracted from the surface of the bioactive glasses. (Am J Dent 2015;28:111-115).

 

 

Mail: Dr. Satin Salehi, CLSB 6N099.A2, 2730 S.W. Moody Avenue, Portland, OR  97201, USA. E-mail: salehi@ohsu.edu

 

 

Modifying the biomechanical response of mouthguards with hard inserts:

A finite element study

 

Crisnicaw Verissimo, dds,ms,phd, Paulo César Freitas Santos-Filho, dds,ms,phd, Daranee Tantbirojn, dds,ms,phd, Antheunis Versluis, phd  &  Carlos JosÉ Soares, dds, ms, phd

 

Abstract: Purpose: To investigate the influence of a high elastic modulus material insert on the stress, shock absorption and displacement of mouthguards. Methods: Finite element models of a human maxillary central incisor with and without mouthguard were created based on cross-sectional CT-tomography. The mouthguard models had four designs: without insert, and middle, external, or palatal hard insert. The hard inserts had a relatively high elastic modulus when compared to the elastic modulus of ethylene vinyl acetate (EVA): 15 GPa versus 18 MPa. A non-linear dynamic impact analysis was performed in which a heavy rigid object hit the model at 1 m/s. Strain and stress (von Mises and critical modified von Mises) distributions and shock absorption during impact were calculated as well as the mouthguard displacement. Results: The model without mouthguard had the highest stress values at the enamel and dentin structures in the tooth crown during the impact. It was concluded that the use of a mouthguard promoted lower stress and strain values in the teeth during impact. Hard insertion in the middle and palatal side of the mouthguard improved biomechanical response by lowering stress and strain on the teeth and lowering mouthguard displacement. (Am J Dent 2015;28:116-120).

 

 

Mail:  Dr. Carlos José Soares, Federal University of Uberlândia. School of Dentistry, Avenida Pará, 1720, Bloco 4L, Anexo A, Sala 42, Campus Umuarama, Uberlândia-Minas Gerais 38400-902  Brazil.   E-mail:  carlosjsoares@umuarama.ufu.br