Saturday, October 31, 2015

Flapless Postextraction Socket Implant Placement, Part 2: The Effects of Bone Grafting and Provisional Restoration on Peri-implant Soft Tissue Height and Thickness- A Retrospective Study.

Int J Periodontics Restorative Dent. 2015 Nov-Dec;35(6):803-9. doi: 10.11607/prd.2178.

Abstract
This article presents the results of evaluating the changes in peri-implant soft tissue dimensions associated with immediate implant placement into anterior postextraction sockets for four treatment groups: no BGPR (no bone graft, no provisional restoration), PR (no bone graft, provisional restoration), BG (bone graft, no provisional restoration), and BGPR (bone graft, provisional restoration). The vertical distance of the peri-implant soft tissue was greater for grafted sites than for nongrafted ones (2.72 mm vs 2.29 mm, P < .06). The facial soft tissue thickness at the gingival third also was greater for grafted than for nongrafted sites (2.90 mm vs 2.28 mm, P < .008) and for sites with provisional restorations compared to sites without them (2.81 mm vs 2.37 mm, P < .06), respectively. The net gain in soft tissue height and thickness was about 1 mm. The increases in vertical and horizontal dimensions for grafted sites were between 0.5 and 1.0 mm, as compared to sites with no bone graft and no provisional restoration.

Friday, October 30, 2015

The influence of peri-implant keratinized mucosa on brushing discomfort and peri-implant tissue health

 

Abstract

Objective

The aim of this study was to compare the level of brushing discomfort (BD) during oral hygiene and peri-implant clinical variables between patients presenting implant sites with a band ≥2 mm and <2 keratinized="" mm="" mucosa="" nbsp="" of="" p="">

Materials and Methods

Participating patients were recruited during routine maintenance follow-up visits from January to October 2013. Based on the presence of KM, patients were allocated into two groups: implant sites with ≥2 mm of KM (Wide Group); and implant sites with <2 all="" analog="" and="" around="" arrow="" asked="" aspect="" assessed="" at="" attachment="" bd="" bleeding="" buccal="" clean="" cleaning="" clinical="" clinically="" collected="" data="" depth="" devices="" each="" em="" experimental="" from="" group="" hygiene="" implant.="" implant="" index="" instructions="" km="" level="" mm="" nbsp="" non-paired="" of="" on="" op="" oral="" patients="" plaque="" pocket="" probing="" received="" reported="" s="" scale="" sites.="" sites="" standardized="" student="" subsequently="" the="" three="" to="" using="" visual="" were="">t
-test, Wilcoxon's signed-rank test, and chi-square tests were performed to analyze the outcome variables (< 0.05).

Results

Eighty patients with a total of 270 implant sites were included. Implant sites in the Narrow Group exhibited higher levels of BD (P < 0.001), PI (P = 0.0021), and BoP (P = 0.017) than implant sites in the Wide Group.

Conclusion

Implant sites with a band of <2 accumulation="" and="" be="" brushing="" compared="" discomfort="" implant="" inflammation="" km.="" km="" mm="" more="" nbsp="" of="" p="" peri-implant="" plaque="" prone="" shown="" sites="" soft="" tissue="" to="" were="" when="" with="">

Thursday, October 29, 2015

Bone grafts utilized in dentistry: an analysis of patients' preferences

BMC Medical Ethics 2015, 16:71  doi:10.1186/s12910-015-0044-6
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6939/16/71

 

Abstract

Background

Many procedures currently require the use of bone grafts to replace or recover bone volume that has been resorbed. However, the patient’s opinion and preferences must be taken into account before implementing any treatment. Researchers have focused primarily on assessing the effectiveness of bone grafts rather than on patients' perceptions. Thus, the aim of this study was to explore patients' opinions regarding the different types of bone grafts used in dental treatments.

Methods

One hundred patients were randomly chosen participated in the study. A standardized survey of 10 questions was used to investigate their opinions regarding the different types of bone grafts used in dental treatments. Descriptive statistics were calculated for the different variables, and absolute frequencies and percentages were used as summary measures. A value of p <0 .05="" as="" for="" p="" selected="" significance.="" statistical="" the="" threshold="" was="">

Results

The highest rate of refusal was observed for allografts and xenografts. The grafts with the lowest rates of refusal were autologous grafts (3 %) and alloplastics (2 %). No significant differences were found between the various types of bone grafts in the sociodemographic variables or the refusal/acceptance variable. Similarly, no significant relations were observed between a specific religious affiliation and the acceptance/refusal rates of the various types of graft.

Conclusions

Allografts and xenografts elicited the highest refusal rates among the surveyed patients, and autologous bone and alloplastics were the most accepted bone grafts. Moreover, no differences were found in the sociodemographic variables or religious affiliations in terms of the acceptance/refusal rates of the different bone grafts.

Wednesday, October 28, 2015

Flapless versus open flap techniques of implant placement: A 15-month follow-up study

Wadhwa B, Jain V, Bhutia O, Bhalla AS, Pruthi G. Flapless versus open flap techniques of implant placement: A 15-month follow-up study. Indian J Dent Res 2015;26:372-7

Aim: To evaluate and compare the effect of flapless and “open flap” techniques of implant placement on crestal bone height (CBH) around implants.  

Materials and Methods: This prospective study comprised of 32 implants placed in 16 subjects with a bilateral missing mandibular first molar. In each subject, one implant was placed with “flapless” and other using “open flap” technique. Radiographic assessment of CBH was carried out using standardized intraoral periapical radiograph of the site at baseline, 3 months, 9 months and 15 months after implant placement.

Statistical Analysis: Data were analyzed using STATA 11.0 statistical software. To determine the changes in CBH from baseline, at 3-, 9-, and 15-month, repeated measures analysis of variance followed by post-hoc Bonferroni was used for each of the two techniques for mesial and distal aspects separately. For both techniques, changes in CBH from baseline to 15 months were compared using an independent t-test with a confidence interval of 95%.

Results: For “flapless” technique, there was no statistically significant (P > 0.05) reduction of CBH in initial 9 months but was significant for the 9–15 months period while for “open flap” technique, statistically significant (P < 0.05) reduction was observed up to 15 months. Comparison of both techniques showed significantly lesser reduction with “flapless” than “open flap” technique. The overall average crestal bone loss was 0.046 ± 0.008 mm on mesial aspect, 0.043 ± 0.012 mm on distal aspect with “flapless” technique and 1.48 ± 0.085 mm on mesial aspect, 1.42 ± 0.077 on distal aspect “open flap” technique.

 Conclusions: Both techniques showed a reduction in CBH with time but the flapless technique showed a lesser reduction. Therefore, the flapless technique can be considered as a better treatment approach for placement of implants, especially where adequate width and height of available bone are present.

Tuesday, October 27, 2015

The Detection of Simulated Periapical Lesions in Human Dry Mandibles with Cone Beam Computed Tomography - A Dose Reduction Study

Abstract

Aim

To assess in an ex vivo model the accuracy of detection of simulated periapical lesions using two CBCT dose modes and periapical radiography.

Methodology

Small and large artificial periapical lesions were created with burs at the base of the socket of eleven mandibular molars, in 7 human dry mandibles. Digital periapical radiographs, 360° and 180° rotations CBCT scans with standard dose and dose reduction (DR) modes were obtained before and after periapical lesions were prepared. Six blinded examiners scored the presence/absence of lesions. Inter- and intra-examiner reliability were determined. Sensitivity, specificity, positive predictive values and negative predictive values and receiver operating characteristic (ROC) area under the curve (overall accuracy) were determined for each modality.

Results

The mean sensitivity and specificity of both CBCT rotations with dose reduction mode were higher compared to that of standard dose CBCT scans. The ROC Az mean values for periapical radiographs, 360° scan with standard dose and dose reduction and 180° scans with standard dose and dose reduction were 0.62, 0.94, 0.95, 0.95 and 0.97, respectively. No significant difference in the diagnostic accuracy of CBCT scans taken with standard and dose reduction modes, while their accuracy was significantly higher than periapical radiographs.

Conclusions

Using dose reduction with 360° and 180° CBCT scans demonstrated good diagnostic accuracy in the detection of simulated periapical lesions while reducing the radiation dose by 54%, and 51% respectively compared to conventional settings. Clinical evaluation is now needed to determine whether this is applicable to patients.

Monday, October 26, 2015

Comparative in vitro wear resistance of CAD/CAM composite resin and ceramic materials

Journal of Prosthetic Dentistry

Abstract

Statement of problem

Composite resin is a promising option in computer-aided design and computer-aided manufacturing (CAD/CAM) dentistry; however, the wear resistance of composite resin remains a primary concern.

Purpose

The purpose of this in vitro study was to evaluate the wear resistance of 5 CAD/CAM materials (n=10), consisting of 4 composite resins (3M Lava Ultimate, Kerr experimental composite resin material, Vita Enamic, 3M Paradigm MZ100) and 1 ceramic (Vita Mark II) in contact with natural human enamel cusps.

Material and methods

Specimens were loaded into a computer-controlled mastication simulator and subjected to 200000 mechanical cycles (49 N) against natural human enamel simultaneously with 500 thermal cycles (5°C to 50°C to 5°C). The wear resistance was analyzed by measuring the vertical substance loss (the maximum depth of the worn area) in the contact point area of the specimen. The worn surfaces were observed by scanning electron microscopy to determine the wear patterns.

Results

Vita Mark II exhibited the best wear resistance among the tested materials, followed by 3M Lava Ultimate, Vita Enamic, and 3M Paradigm MZ100. The Kerr experimental material exhibited the lowest wear resistance, yet its results were not significantly different from those of the 3 other composite resin blocks (P>.05).

Conclusions

Within the limitations of this in vitro study, the wear resistance of composite resin blocks in contact with enamel cusps was significantly lower than that of a ceramic block.

Friday, October 23, 2015

WHOLE You™ LaunchES its first denture product, WHole You Nexteeth™, AND NEW oral appliances for obstructive sleep apnea and snoring



Whole You Nexteeth utilizes CAD/CAM technology and advanced materials to create a more comfortable, better fitting full denture

Whole You Sleep Appliances - Respire Pink Endurance Framework (EF) and Respire Pink Micro - offer more comfortable options for those looking for new solutions to get a better night’s sleep

SAN JOSE, Calif. (October 13, 2015) – Whole You, Inc., a Mitsui Chemicals company dedicated to providing innovative solutions that allow those with sensory and physical mobility challenges to live life to the fullest, today announced the launch of three new products. Marking its entry into the denture market, Whole You Nexteeth full denture utilizes CAD/CAM technology, combined with advanced material to offer a precise fitting and a thinner palatal plate resulting in enhanced comfort to wear.

To complement the company’s current portfolio of oral appliances for obstructive sleep apnea and snoring, the company has launched new Whole You Sleep Appliances - Respire Pink Endurance Framework (EF) and Respire Pink Micro. These oral appliances provide extra wearing comfort and are specially-designed for those that require additional tongue space, or for those with a smaller mouth. 

“Our mission at Whole You is to enable people to live a full life and enjoy the pleasures of the world around them uninhibited by sensory or physical limitations,” says Yasunori Nishiyama, chief executive officer, Whole You, Inc. “We are very proud of our new product offerings as there is a need to offer more comfortable solutions in the oral category that helps consumers feel their best so they can fully experience the joys of the world around them. Expect other exciting and experience-enhancing products from us in the coming months.”

About Whole You Nexteeth

The technology behind Whole You Nexteeth has been researched for a number of years to ensure a precise fitting and comfortable denture. The multifunctional Whole You DENTCA tray accelerates and improves the denture making process by allowing impressions and bite registration to be taken in one office visit. The Whole You DENTCA tray impressions are combined with CAD technology to reduce dentist visits and create digital denture design. Using the design and precise milling process, Nexteeth provides enhanced comfort to wear, fabricated with advance resin material for durability and a unique coating for easy cleaning and care.

About Whole You Sleep Appliances for obstructive sleep apnea and snoring

Newly developed Whole You Sleep Appliances, Respire Pink EF and Respire Pink Micro, for obstructive sleep apnea and snoring offer more comfortable options to help sleep apnea patients wake up refreshed. Oral appliances for obstructive sleep apnea work by opening up the airway for better airflow, while holding the jaw in position to prevent it from falling back and obstructing the airway.

Respire Pink EF utilizes a durable alloy material to create one of the thinnest lingual coverage products that allow for increased comfort to wear and tongue space. Respire Pink EF utilizes telescopic hardware allowing lateral and vertical movement of the mouth, making it suitable for those that also suffer from bruxism, or teeth grinding.

Respire Pink Micro is a custom-fit appliance with newly-developed shorter adjustment arms for increased comfort to wear, particularly for those with a smaller mouth. Utilizing telescopic hardware that allows for lateral and vertical movement, Pink Micro is also suitable for obstructive sleep apnea patients that grind their teeth.

Additionally, Whole You is expecting to launch the Respire Blue Endurance Framework (EF) oral appliance soon. It also utilizes the durable alloy material that creates one of the thinnest lingual coverage products and offers a dual block design with interlocking wings. This makes the Respire Blue EF less intrusive and offers freedom to open and close the mouth.

Nexteeth is now available. Respire Pink EF and Pink Micro will be launched on Oct 19. Visit www.wholeyou.com for more information.

About Whole You
By combining open innovation with a wide range of partners, material innovation and a deep understanding of market needs, Whole You Inc., a Mitsui Chemicals company, is committed to offering solutions that allow those with sensory and physical mobility challenges to live life to the fullest. With its partners Respire Medical and DENTCA and through the acquisitions of PixelOptics and Panasonic Healthcare technology, Whole You is pushing the boundaries of technology to greatly improve how life is experienced by millions of Americans.

Whole You is headquartered in San Jose, Calif. For more information, please visit www.wholeyou.com. Follow us on Facebook (www.facebook.com/wholeyouinc), Twitter (www.twitter.com/wholeyouinc) and LinkedIn (https://www.linkedin.com/company/whole-you).
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Thursday, October 22, 2015

Using an Er,Cr:YSGG laser to remove lithium disilicate restorations: A pilot study

Journal of Prosthetic Dentistry
Article in press

Abstract

Statement of problem

The use of lasers is growing widely in dentistry. Despite its clinical implications, most information and clinical data related to the removal of ceramic restorations with the aid of a laser is either anecdotal or in the form of clinical reports.

Purpose

The purpose of this in vitro study was to establish a parameter on the removal of lithium disilicate crowns with a laser and conduct an in vitro trial of crown removal based on the wattage and time of application.

Material and methods

Twenty extracted molars were prepared to accommodate a lithium disilicate disk specimen, which was cemented with resin cement. An erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser was applied at different wattages (3, 3.5, 4, and 5 W) to determine the optimal wattage for the removal of the lithium disilicate specimens. Once the optimal wattage was established, 25 extracted teeth were mounted in stone, then prepared to receive milled lithium disilicate computer-aided design/computer-aided manufacturing complete coverage crowns. The crowns were cemented with a dual-polymerizing resin cement. The groups comprised 3.5 and 4 W output with 30-, 60-, and 90-second application time (n=5), and 5 crowns were removed using traditional handpiece and electric handpiece with coarse grit diamond rotary instruments. The results and time required to remove the crown were recorded. The chi-square test was performed to assess any significant differences in removing the crown with the laser according to wattage or time of application (α=.05).

Results

Laser application at 3.5 and 4 W was best for removing crowns conservatively. Eight crowns (40%) of 20 specimens were successfully removed at the first attempt. The majority of the crowns came off during the second attempt. The chi-square test revealed no significant difference between the combination of wattage and time of application (P= .92). The mean time to remove the lithium disilicate crown with a diamond rotary instrument was 6 minutes, and removal required 1.8 instruments on the average.

Conclusions

An Er,Cr:YSGG laser can safely remove lithium disilicate crowns with the settings used this study.

Wednesday, October 21, 2015

A comparison of a new alcohol-free 0.2% chlorhexidine oral rinse to an established 0.2% chlorhexidine rinse with alcohol for the control of dental plaque accumulation

Int J Dent Hygiene DOI: 10.1111/idh.12182 Papaioannou W, Vassilopoulos S, Vrotsos I, Margaritis V, Panis V. A comparison of a new alcohol-free 0.2% chlorhexidine oral rinse to an established 0.2% chlorhexidine rinse with alcohol for the control of dental plaque accumulation.

 

Abstract

Objectives

To compare the clinical efficacy of two formulations (alcohol and alcohol free) of 0.2% chlorhexidine (CHX) rinses on plaque, gingivitis and discoloration of teeth.

Methods

This double-blind crossover study consisted of one group of 10 volunteer dental students that followed two 21-day experimental gingivitis test periods. During these periods, the subjects abstained from oral hygiene except for the oral rinse provided. The study started after an initial two-week preparation programme that included a professional prophylaxis and repeated oral hygiene instructions. This was repeated for the 14-day washout period between the two rinses, including prophylaxis as per the first stage of the study. A calibrated examiner performed the clinical measurements at the beginning (baseline) and end of each study stage. The presence and amount of plaque were recorded using the Silness and Löe plaque index (PI) and gingival inflammation by the gingival index (GI) while the discoloration index (DI) was recorded on the buccal and lingual surfaces of the six anterior teeth of both the mandible and maxilla.

Results

Mean PI increased similarly for both solutions; however, the differences between initial and final values were statistically significant only for CHLOREL®. Similarly, the mean values for the GI showed small increases over the course of the study periods, but not statistically significant for either solution. The mean DI increased significantly for both solutions. Regarding the comparison of the initial and final values ​​between the solutions, per index, no statistically significant differences were observed.

Conclusion

The non-alcoholic chlorhexidine rinse had comparable levels of action as the generally recognized gold standard alcoholic rinse.

Tuesday, October 20, 2015

Effect of gingival displacement cord and cordless systems on the closure, displacement, and inflammation of the gingival crevice

 

Abstract

Statement of problem

The gingival sulcus should remain open long enough for the impression material to flow into it and completely fill the space provided by the gingival displacement. Impressions with less sulcal width have a higher incidence of voids, tearing of impression materials, and reduction in marginal accuracy.

Purpose

The purpose of this study was to investigate the closure, gingival displacement, and gingival inflammation of the gingival crevice after the use of medicated gingival displacement cord and cordless systems.

Material and methods

Gingival sulcus closure was studied in 40 participants. They were divided into 4 groups: 2 cord (Ultrapack, SilTrax AS) and 2 cordless (Expasyl, Traxodent Hemodent paste) methods. The labial surfaces of the maxillary right and left central incisors were evaluated. Gingival sulcus was photographed every 20 seconds from 0 to 180 seconds after the removal of the cord or cordless system. The bleeding index (BI) and gingival index (GI) were measured at day 0, day 1, and day 7. The width of the sulcal orifice was measured at the mid-buccal (MB) and transitional line angle (TLA) on a digital image, using computer software (Photoshop version 7.0; Adobe). Data were analyzed with ANOVA, Tukey honest significant difference (HSD), Kruskal-Wallis, and Mann-Whitney U tests (α=.05).

Results

All groups showed a sulcal width greater than 0.22 mm up to 60 seconds after the removal of the displacement materials at the MB and up to 40 seconds at the TLA. Among all groups, Expasyl showed the fastest closure. Gingival displacement in the MB area for the cord group was greater than for the cordless groups. GI and BI indices were larger for the cord group than for the cordless group at days 0 and 1.

Conclusions

At up to 60 seconds, the cord and cordless techniques were equally effective. The cord group showed a greater amount of displacement than the cordless group. However, the cordless materials showed reduced frequency of changes to the gingival index.

Monday, October 19, 2015

Sleep Bruxism in individuals with and without attrition-type tooth wear: An exploratory matched case-control electromyographic study

 

Abstract

Objectives

To examine if there is a difference in possible sleep bruxism activity (SB) in subjects with or without attrition-type tooth wear.

Methods

Sixteen individuals with pronounced attritional-type tooth wear were compared with sex and aged matched controls without tooth wear by means of measurement of electromyographic (EMG) activity during a minimum of four consecutive nights of sleep. Mean age and range for the study- and control- group was 23.7 years (range 19.9–28.5) and 23.6 years (range 20.3–27.9), respectively. There were 11 females and five males in each of the two groups. The attrition group presented incisal/occlusal attrition wear into dentin and matching wear facets between opposing anterior teeth. The controls had negligible signs of incisal/occlusal wear and a minimal number of matching wear facets.

Results

The prevalence of both self-reported and partner-reported SB was significantly more common in the attrition group compared to the controls (P = 0.04 and P = 0.007, respectively). Self-reported morning facial pain was similarly more common in the attrition group (P = 0.014). Maximum opening capacity, number of muscles painful to palpation, salivary flow rate and buffering capacity were not significantly different between the groups. Interestingly, none of the measures of jaw muscle EMG activity during sleep, as recorded by the portable EMG equipment, differed significantly between the attrition group and the matched controls (P > 0.05).

Conclusions

The results from this exploratory study suggest that there is no difference in EMG activity between subjects with and without attrition-type tooth wear. Further research is needed in order to substantiate these preliminary findings.

Friday, October 16, 2015

Mechanical properties, shrinkage stress, cuspal strain and fracture resistance of molars restored with bulk-fill composites and incremental filling technique

 

ABSTRACT

Objectives: To compare bulk-fill with incremental filling techniques for restoring large mesio-occlusal-distal (MOD) restorations.

Methods

Seventy-five molars with MOD preparations were divided into five groups: Z350XT, incrementally filled with Filtek Z350XT and four bulk-fills - FBF/Z350XT, Filtek Bulk Fill/Filtek Z350XT; VBF/CHA, Venus Bulk Fill/Charisma Diamond; SDR/EST-X, SDR/Esthet-X HD; TEC, TetricEvoCeram Bulk Fill. Cuspal strains were measured using strain-gauges (n=10): CSt-Re, during restorative procedure; CSt-100N, during 100N occlusal loading; CSt-Fr, at fracture load. Before fracture load, teeth were load-cycled. Fracture resistance, fracture mode, and enamel cracks were recorded. The other five teeth were used for Elastic modulus (E) and Vickers hardness (VH). Post-gel shrinkage (Shr), diametral tensile strength (DTS) and compressive strength (CS) were determined (n=10). Shrinkage stresses were analyzed using finite element analysis.

Results

SDR had similar CS values as TEC, lower than all other composites. CHA had similar DTS values as Z350XT, higher than all other composites. Z350XT had the highest mean Shr and SDR the lowest Shr. New enamel cracks and propagation was observed after the restoration, regardless of filling technique. Z350XT had lower fracture resistance than bulk-fill composite techniques. No significant differences in failure modes were found. E and VH were constant through the depth for all techniques. Bulk-filling techniques had lower stresses compared to Z350XT.

Conclusions

Flowable bulk-fill composites had lower mechanical properties than paste bulk-fill and conventional composites. All bulk-fill composites had lower post-gel shrinkage than conventional composite. Bulk-fill filling techniques resulted in lower cusp strain, shrinkage stress and higher fracture resistance.

Clinical significance

Using bulk-fill composites cause lower CSt wich indicates lower stress in restored tooth. Furthermore, bulk-fill composites have a higher fracture resistance. Therefore, clinicians may choose the bulk-fill composite to decrease undesirable effects of restoration while simplifying filling procedure.

Thursday, October 15, 2015

Long-term sorption and solubility of bulk-fill and conventional resin-composites in water and artificial saliva

Abstract

Objectives

To assess sorption and solubility of several bulk-fill and conventional resin- composites after one-year storage in water and artificial saliva (AS).

Methods

Six bulk-fill (SureFil SDR, Venus Bulk Fill, X-tra base, Filtek Bulk Fill flowable, Sonic Fill, and Tetric EvoCeram Bulk Fill) and eight conventional resin-composites (Grandioso Flow, Venus Diamond Flow, XFlow, Filtek Supreme XTE, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested. Disc shaped samples (n= 5) were randomly immersed into distilled water and AS for one-year period and weighed at different time intervals. Data were analysed using repeated measures ANOVA, one-way ANOVA, and Tukey's post hoc test (α=0.05).

Results

In water, all materials (with the exception of X- Flow) reached a stable mass within three months with a slow increase observed in AS up to one year. Sorption values in water and AS for most materials were not significantly different (p≥ 0.2). Sorption and solubility values in water ranged from (6.5μg/mm3 and -1.77μg/mm3 respectively) for X-tra base to (78.8μg/mm3 and 44.77 μg/mm3 respectively) for X- Flow (p< 0.005). Sorption of the polymer matrix in water ranged from 1.18 % for XB to 9.95 % for XF.

Conclusions

Water sorption and solubility of resin-composites are material-dependent and highly affected by the filler loading and hydrophilicity of the resin matrix. BisEMA and UDMA-BisEMA based resins appeared to be more hydrophobic than BisGMA based systems. Water and AS, are generally comparable as storage media in terms of water sorption.

Clinical significance

Bulk-fill materials and conventional resin-composites tested varied in terms of sorption and solubility but both were considered stable in longterm water storage. The composition of each material is critical and can affect the long-term clinical performance of either type of resincomposites

Wednesday, October 14, 2015

Accessory mental foramina and nerves: Application to periodontal, periapical, and implant surgery

 Iwanaga, J., Watanabe, K., Saga, T., Tabira, Y., Kitashima, S., Kusukawa, J. and Yamaki, K.-I. (2015), Accessory mental foramina and nerves: Application to periodontal, periapical, and implant surgery. Clin. Anat.. doi: 10.1002/ca.22635



Recent studies investigating accessory mental foramina using developments in diagnostic imaging have primarily defined the morphology of the foramina; however, few studies have described the structures passing through them. Additional clinical knowledge of the foramina is therefore required for preoperative diagnosis prior to surgery, including implant, periodontal and periapical surgery. In this study, we investigated the accessory mental foramina and the associated nerves and arteries in donated cadaveric mandibles using anatomical and radiological observation methods. We examined 63 mandibles with overlying soft tissue by cone-beam computed tomography and noted the existence of the accessory mental foramina. Mandibles with accessory mental foramina were subsequently analyzed. Additionally, the neurovascular bundles passing through these foramina were dissected using anatomical methods.The incidence of accessory mental foramina was 14.3%. The larger foramina tended to be located anteriorly or superiorly and proximal to the mental foramen, while the smaller foramina tended to be located posterosuperiorly and distal to the mental foramen. The mental foramen ipsilateral to the accessory mental foramen was smaller than the one contralateral to it. The comparatively distant and large accessory mental foramen included an artery.This study elucidated the relationship between accessory mental foramina and the associated nerves and arteries. We believe that the results will contribute to the clinical dentistry field. Clin. Anat., 2015. © 2015 Wiley Periodicals, Inc.

Tuesday, October 13, 2015

Effect of the Probiotic Lactobacillus rhamnosus LB21 on the Cariogenicity of Streptococcus mutans UA159 in a Dual-Species Biofilm Model

Logo Caries Research 

Vol. 49, No. 6, 2015
Issue release date: Published online first (Issue-in-Progress)


Abstract

Despite promising results using probiotics, evidence of the preventive effect on enamel demineralization is insufficient and the cariogenic potential of probiotics is still controversial. Probiotics could affect biofilm formation and interfere with adherence, growth or coaggregation with Streptococcus mutans in biofilms. However, most of the studies have been conducted using planktonic bacteria. Hence, the aim of the study was to assess the effect of probiotic bacteria on the cariogenicity of S. mutans using an in vitro biofilm caries model on enamel. Single-species biofilms (S. mutans UA159, SM or Lactobacillus rhamnosus LB21, LB) or dual-species biofilms simultaneously inoculated (SM + LB) or LB inoculated 8 h after SM (SM → LB) were grown for 96 h. Biofilms were formed on bovine enamel saliva-coated slabs of known surface hardness (SH) and immersed in culture media. Biofilms were exposed 8 times per day to 10% sucrose. Medium pH was monitored twice daily as a biofilm acidogenicity indicator. After 96 h, biofilms were collected to determine biomass and bacteria viability. Slab demineralization was calculated as percentage of SH loss (%SHL). Additionally, the model was tested with different concentrations of the initial inoculum (103, 106, 108 cells/ml) and different adhesion times (2 or 8 h). The dual-species biofilm revealed no LB effects on SM cariogenicity, without changes in acidogenicity or %SHL among groups (p > 0.05, n = 12). Lack of activity of LB on SM cariogenicity persisted even when 105 times higher concentration of the probiotic was tested. Coaggregation was not observed. In conclusion, findings suggest that LB does not reduce cariogenicity of SM in a validated experimental caries model.
© 2015 S. Karger AG, Basel

Monday, October 12, 2015

Retreatability of different endodontic sealers using chemical solvents

Available online 19 September 2015

 

Abstract

Objectives

The aim of this study was to evaluate the efficacy of removal of different sealers using ProTaper Retreatment System applying different solvents.

Methods

Root canals in 135 single-rooted teeth were instrumented and obturated with gutta-percha using one of the following sealers (n = 45): group A; MTA Fillapex sealer, group B; AH Plus and group C; Endofill sealer. After one month, the root canals were retreated with a rotary retreatment system; ProTaper Universal Retreatment kit using different solvents according to the subgroups: (n = 15) subgroup D; DMS IV, subgroup E; EndoSolv R and subgroup N; no solvent was used. Roots were split longitudinally, canals were observed using a stereomicroscope at 20×. The images were subjected to morphometric analysis to assess the amount of remaining root filling material. Statistical analysis was performed by two way ANOVA and Student–Newman Keuls post-hoc test was done for pair-wise comparison.

Results

Group B showed significantly (P = 0.004) higher values of residual root filling material than groups A & B in case of no-solvent use (subgroup N). During the use of EndoSolv R (subgroup E), no significant difference (P = 0.34) was found between all groups. However, with use of DMS IV (subgroup D), Group B recorded the highest significant value followed by group A then the group C.

Conclusions

Resin solvent was efficient in removal of resin and MTA based sealers while DMS IV is only beneficial with removal of zinc oxide and eugenol based sealers.

Friday, October 09, 2015

Early Implant Failures Related to Individual Surgeons: An Analysis Covering 11,074 Operations Performed during 28 Years

Clinical Implant Dentistry and Related Research
Article first published online: 24 SEP 2015
DOI: 10.1111/cid.12379

 

Abstract

Background

Compared with knowledge on patient and implant component factors, little knowledge is available on surgeons' role in early implant failures.

Purpose

To report incidence of early implant failures related to total number of operations performed by individual surgeons.

Materials and Methods

Early implant failures (≤1 year of implant prosthesis function) were reported after a total of 11,074 implant operations at one specialist clinic during 28 years of surgery. Altogether, 8,808 individual patients were treated by 23 different dentists, of whom 21 surgeons were specialists in oral surgery or periodontology. Recorded failures were related to total numbers of performed operations per surgeon, followed by statistical comparisons (χ2) between surgeons with regard to type of treated jaw and implant surface.

Results

Altogether, 616 operations were recorded with early implant failures (5.6%), most often observed in edentulous upper jaws after placing implants with a turned surface (p < .05). Significant differences between surgeons, gender of surgeon, type of treated jaws by the surgeon, and implant surface used by the surgeon could be observed (p < .05).

Conclusions

Early implant failures are complex, multifactorial problems associated with many aspects in the surgical procedure. A stochastic variation of failures for individual surgeons could be observed over the years. Different levels of failure rate could be observed between the surgeons, occasionally reaching significant levels as a total or for different jaw situations (p < .05). The surgeons reduced their failure rates when using implants with moderately rough surfaces (p < .5), but the relationship of failure rate between the surgeons was maintained.

Thursday, October 08, 2015

The efficacy of two oral hygiene regimens in reducing oral malodour: a randomised clinical trial

Cover image for Vol. 65 Issue 5
International Dental Journal
Article first published online: 24 SEP 2015
DOI: 10.1111/idj.12183

 

Objectives

This study compared the efficacy of two oral hygiene regimens in reducing oral malodour and the proportions of bacterial species involved in the production of volatile sulphur compounds.

Material and Methods

Seventy subjects who participated in a halitosis-induction phase and achieved an organoleptic score of ≥3.0 [time point 0 (T0)] randomised into two groups: brushing with regular fluoride toothpaste alone (control group) or brushing with regular fluoride toothpaste followed by rinsing with a 0.075% cetylpyridinium chloride (CPC) mouthwash (CPC group). Subjects followed their assigned oral hygiene regimen for 21 days. Then, they underwent an organoleptic examination and measurement of volatile sulphur compounds (VSCs) using a portable gas chromatograph, 12 hours after their last oral hygiene procedure (T1) and 4 hours after an on-site oral hygiene (T2). Microbiological samples (supragingival biofilm, tongue coating and saliva) were analysed using checkerboard DNA–DNA hybridisation.

Results

Both therapies statistically significantly improved the organoleptic scores (P < 0.05), but the VSC levels and/or concentrations were reduced only in the CPC group (P < 0.05). In subjects rinsing with CPC, oral malodour scores were reduced by 49% at the 4-hour assessment (T2) compared with those not rinsing (P < 0.05). Red-complex pathogens were reduced more effectively in the CPC group than in the control group.

Conclusions

Brushing followed by rinsing with a 0.075% CPC mouthwash provided statistically significantly greater reductions in oral malodour, measured organoleptically and instrumentally, and in the proportions of red-complex species when compared with brushing alone.

Wednesday, October 07, 2015

Fracture resistance of monolithic zirconia crowns with different occlusal thicknesses in implant prostheses

Journal of Prosthetic Dentistry Home

Publication stage: In Press Corrected Proof

Abstract

Statement of problem

The use of monolithic zirconia crowns in implant prostheses is increasing, especially when the interdental space is insufficient. However, fractures have been reported in clinical practice.

Purpose

The purpose of this study was to determine the minimal thickness of a complete zirconia crown used for an implant prosthesis in the posterior dental region.

Material and methods

Fifty complete zirconia crowns were produced using a computer-aided design/computer-aided manufacturing technique. In each group, 5 crowns of varying thicknesses (0.4, 0.5, 0.6, 0.7, and 0.8 mm) were subjected to cycles of vertical and 10-degree oblique compressive loading at 5 Hz and 300 N in a servohydraulic testing machine. Five finite element models comprising 5 different occlusal thicknesses (0.4, 0.5, 0.6, 0.7, and 0.8 mm) were simulated at 2 loading angles (0 and 10 degrees) and 3 loading forces (300, 500, and 800 N). Data were statistically analyzed, and fracture patterns were observed with a scanning electron microscope.

Results

Cyclic loading tests revealed that the fracture resistance of the specimens was positively associated with prosthesis thickness (P<.01). Low von Mises stress values were obtained for prostheses with a minimal thickness of 0.7 mm under varying loading directions and forces.

Conclusions

Zirconia prostheses with a minimal thickness of 0.7 mm had a high fracture resistance and the lowest stress values. Therefore, dentists and laboratory technicians should carefully choose the optimum thickness of zirconia prostheses.

Tuesday, October 06, 2015

Effect of probiotic chewing tablets on early childhood caries – a randomized controlled trial

BMC Oral Health 2015, 15:112  doi:10.1186/s12903-015-0096-5
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6831/15/112

 

Background

To evaluate the effect of probiotic chewing tablets on early childhood caries development in preschool children living in a low socioeconomic multicultural area.

Methods

The investigation employed a randomized double-blind placebo-controlled design. The study group consisted of 138 healthy 2-3-year-old children that were consecutively recruited after informed parental consent. After enrollment, they were randomized to a test or a placebo group. The parents of the test group were instructed to give their child one chewing tablet per day containing three strains of live probiotic bacteria (ProBiora3®) and the placebo group got identical tablets without bacteria. The duration was one year and the prevalence and increment of initial and manifest caries lesions was examined at baseline and follow-up. All parents were thoroughly instructed to brush the teeth of their off-springs twice daily with fluoride toothpaste.

Results

The groups were balanced at baseline and the attrition rate was 20 %. Around 2/3 of the children in both groups reported an acceptable compliance. The caries increment (Δds) was significantly lower in the test group when compared with the placebo group, 0.2 vs. 0.8 (p < 0.05). The risk reduction was 0.47 (95 % CI 0.24–0.98) and the number needed to treat close to five. No differences were displayed between the groups concerning presence of visible plaque or bleeding-on-brushing. No side effects were reported.

Conclusions

The results suggested that early childhood caries development could be reduced through administration of these probiotic chewing tablets as adjunct to daily use of fluoride toothpaste in preschool children. Further studies on a possible dose–response relationship seem justified

Monday, October 05, 2015

Tooth-implant-supported posterior fixed dental prostheses with zirconia frameworks: 3-year clinical result

Clinical Oral Investigations
pp 1-8
First online:

Clinical Oral Investigations

Abstract

Objectives

This case series compared the clinical survival of tooth-implant-supported (TI-S) and tooth-supported (T-S) three-unit fixed dental prostheses (FDPs) with zirconia frameworks and described the incidence of biological and technical complications.

Materials and methods

Forty-four patients received 27 TI-S FDPs and 22 T-S FDPs. Twenty-seven titanium screw implants were inserted at the dislodged position of two missing posterior teeth. All implants were provided with customized zirconia abutments. Zirconia frameworks were fabricated by a CAD/CAM system and veneered in powder build-up technique. All restorations were cemented with glass ionomer. Baseline evaluation was performed 2 weeks after cementation with recall examinations performed at 6, 12, 24 and 36 months by calibrated investigators. Survival probabilities according to Kaplan-Meier were calculated. Gingival parameters and bone loss were assessed and statistically evaluated.

Results

The mean service time of the FDPs was 35 months (±6). Two technical complications (fracture of veneering porcelain) were observed. One biological complication was recorded. The Kaplan-Meier survival probability was 93.9 % for all types of complications and 100 % related to restorations in service. The type of abutment support (TI-S vs. T-S) had no significant influence on the survival probability (p = 0.412, log rank test). No difference of the gingival parameters was detected between implants and natural teeth.

Conclusions

Tooth-implant-supported zirconia-based FDPs showed similar clinical performance compared to tooth-supported zirconia-based FDPs.

Clinical relevance

Within the limitations of this case series, tooth-implant-supported FDPs with zirconia frameworks seem to be a reliable treatment option.


Friday, October 02, 2015

Eaglesoft Celebrates 21st Birthday in Las Vegas


Event Showcased Software Features and Tools for Practice Success

ST. PAUL, Minn. (September 28, 2015) – Eaglesoft Practice Management System celebrated its 21st birthday by showing users how to find, implement and measure success in their practices. At a celebration held in conjunction with the CEREC 30th Anniversary Celebration on September 17 – 19 in Las Vegas, event attendees met with Eaglesoft experts and participated in training sessions focused on how to create a more successful and profitable practice.

Attending Eaglesoft users were given the opportunity to explore features of the system they may not yet be using in their practices, like Eaglesoft Mobile, which allows practices to access the software anywhere at anytime. Attendees took home over 10 hours of invaluable Eaglesoft specific training, along with instrumental advice on how to have an extraordinary practice and life – as both are possible with the right technology.

With plenty of networking opportunities, Eaglesoft users gathered to share stories and tell first-hand experiences about the ways Eaglesoft has helped their practices grow and succeed, along with many useful tips and tricks they’ve learned along the way for both using the software and managing their businesses. Best yet, attendees were some of the first to get a sneak peak of Eaglesoft 18 and the new features and benefits it has to offer.

 “Our goal is to help dental practices find, implement and measure success, which is exactly what we were able to do at this event, and what we will continue to focus on for the next iteration of the software, Eaglesoft 18,” said Jana Berghoff, technology marketing manager of Patterson Dental. “We couldn’t have asked for a better way to celebrate Eaglesoft’s 21st birthday and we thank all of our attendees for joining in the celebration!”
 
For more information on Eaglesoft, visit www.eaglesoft.net or call 1-800-475-5036.

Thursday, October 01, 2015

KaVo Kerr Group Supports NYU College of Dentistry in Ghana-based Research Project



Dr. Stuart M. Hirsch leads team to study prevalence of periodontal disease in diabetic patients.
Dr. Stuart M. Hirsch, Vice Dean of International Initiatives, Development & Students at the New York University (NYU) College of Dentistry, first visited Ghana approximately five years ago. NYU had students studying in Ghana, and was looking for joint opportunities with the University of Ghana to expand its presence.
Dr. Hirsch and the NYU team — Rachel Hill, Dr. Peter Loomer and Hannah Coakley — and the doctors and staff at the Korle-Bu Teaching Hospital and Dental School were interested in finding out the prevalence of periodontal disease in diabetic patients at the hospital. Type II diabetes is increasing around the world and there is mounting data that suggests an oral-systemic link.
“We wanted to find out the prevalence of periodontal disease in diabetic patients. Previously, we’d conducted a qualitative analysis of periodontal health and diabetes, assessing the knowledge base people have; what they know about diabetes and what they’re doing about it,” Dr. Hirsch explained. “In putting together this new quantitative study, we hope to lay the groundwork for implementation on how to better control periodontal disease in developing countries or impoverished areas. This is a very big deal, as access to care in these environments is limited.”
What does limited mean, in real terms? Consider first, that in the United States, the ratio of patients to dentists is 2,500 to 1. In the developing world, that number is as high as 180,000 to 1. The hardship is great, as is the need for realistic solutions.
This study in Ghana looks at a 220-person patient group. Each individual had a health history taken, as well as Hemoglobin A1c (HbA1c) measurement and a panoramic radiograph to assess the percentage of bone loss around individual’s teeth.
“HbA1c is a way to measure sugar glucose in the blood; the goal for people with diabetes is a level less than 7%, but we saw were as high as 13%,” Dr. Hirsch shared. “We worked with a diabetes clinic in Accra — Ghana’s capital. We would take the HbA1c measurements right before the panoramic digital pan. This is where the OP200D panoramic imaging system provided by Instrumentarium DentalTM was essential. In my opinion, without this equipment to tell us the bone levels, this prevalence study would not have occurred. In my experience, bone levels are

important because they never improve, only worsen. My team can use these acquired images and through our analysis and experience, we can determine the extent of periodontal disease for such a patient population.”
Barbara Nordquist, the VP for Academic Sales & Professional Relations at KaVo Kerr Group, was instrumental in making the donation possible, in coordination with Brian Broncatti, Senior Regional Sales Manager for Instrumentarium. Having worked with Nordquist for a number of years, and recently at NYU on choosing Pelton & CraneTM equipment for a clinic renovation, Dr. Hirsch turned to her for help on the Ghana project.
In addition to providing the necessary imaging equipment, KaVo Kerr Group provided on-site training for the team in Ghana, facilitated by David Bangert, VP/GM of Special Markets for KaVo Kerr Group, who traveled to the country himself. In addition to setting up the team for success, he made himself available for ongoing support during the study.
“Our partnership with KaVo Kerr Group is an example of how educators and the dental industry need one another. There is — or there needs to be — a relationship in order to move forward ideas and desires on both ends,” Dr. Hirsch shared. “We cannot exist in isolation.”
At this point, the data collection in Ghana is complete. Dr. Hirsch intends to have a small group of post-doctoral students help analyze the data — primarily reading the digital panoramic radiographs — with a targeted completion date of Fall 2015. Dr. Hirsch believes that there will be strong correlations between diabetes and periodontal disease, demonstrated by loss of bone as well as soft tissue.
With that analysis in hand, the real work can begin.
“Hopefully, what we get from this is data to support firm decisions on how to best implement preventive care since we can’t offer surgical care in these areas,” Dr. Hirsch said. “This is a very difficult thing. Even patients in a private office struggle to brush and floss consistently; how much more so, then, in areas like Ghana?”
This is why the dual work of helping patients understand the connections between diabetes and periodontal disease is the first phase; it can help create the motivation necessary for preventive care. The second is to figure out what simple, sustainable, preventive care measures can be employed.

“We’re not sure what those tools are yet, but assuming the prevalence is what we think it will be, that is the crucial next step,” Dr. Hirsch proposed. “And once our work is finished in Ghana, we will try to connect what we learn there with the issues we face here at home.”
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