Wednesday, August 16, 2017

Biomechanical behavior of titanium and zirconia frameworks for implant-supported full-arch fixed dental prosthesis


Abstract

Background

The biomechanical behavior of implant-supported titanium and zirconia full-arch fixed dental prosthesis (FAFDP) frameworks require further investigation.

Purpose

Strains transferred by implant-supported titanium (Ti) and zirconia (Zr) FAFDP frameworks were analyzed.

Materials and Methods

Maxillary 14-unit FAFDPs supported by 6 implants and 12-unit FAFDPs supported by 4 implants were tested. One-piece frameworks were fabricated by computer-aided design/computer-aided manufacturing. Four groups were divided (n = 3): G1, Ti-6 implants; G2, Zr-6 implants; G3, Ti-4 implants; G4, Zr-4 implants. A 250 N single-point load was applied on the second premolar. A three-dimensional digital image correlation system recorded framework and maxilla model surface deformation.

Results

The following strains (μS) averaged over the length of the second premolar were calculated: frameworks, G1 (321.82 ± 111.29), G2 (638.87 ± 108.64), G3 (377.77 ± 28.64), G4 (434.18 ± 132.21); model surface, G1 (473.99 ± 48.69), G2 (653.93 ± 45.26), G3 (1082.50 ± 71.14), G4 (1218.26 ± 230.37). Zirconia frameworks supported by 6 implants (G2) presented higher surface strains (P < .05). FAFDPs with titanium frameworks transferred significantly lower strains to the supporting maxilla when 6 implants were used (G1) (P < .05). Both framework materials transferred similar strains when supported by 4 implants (G3 and G4) (P > .05).

Conclusions

Zirconia frameworks supported by 6 implants showed higher strains. FAFDPs supported by 6 implants transferred less strains to the supporting maxilla, irrespective of framework material.

Tuesday, August 15, 2017

Comparison of periodontal evaluation by cone-beam computed tomography, and clinical and intraoral radiographic examinations

Oral Radiology
pp 1–11

Abstract

Objectives

Cone-beam computed tomography (CBCT) has been widely used in many fields of dentistry. However, little is known about the accuracy of CBCT for evaluation of periodontal status. The objective of this study was to compare and correlate periodontal assessments among CBCT, clinical attachment loss (CAL) measurement, and periapical (PA)/bitewing (BW) radiography.

Methods

Eighty patients (28 males, 52 females; age range, 19–84 years) from the University of Texas School of Dentistry at Houston were evaluated retrospectively. Measurements were taken on the central incisors, canines, and first molars of the right maxilla and left mandible. CAL was extracted from periodontal charts. The radiographic distance from the cementum–enamel junction (CEJ) to the alveolar crest was measured for tooth mesial and distal sites on PA/BW and CBCT images using MiPacs software and Anatomage Invivo software, respectively. One-way ANOVA and Pearson analysis were performed for statistical analyses.

Results

The CEJ–crest distances for CBCT, PA/BW, and CAL were 2.56 ± 0.12, 2.04 ± 0.12, and 2.08 ± 0.17 mm (mean ± SD), respectively. CBCT exhibited larger values than the other two methods (p < 0.05). There were highly significant positive correlations among CBCT, PA/BW, and CAL measurements at all examined sites (p < 0.001). The Pearson correlation coefficient was higher for CBCT with CAL relative to PA/BW with CAL, but the difference was not significant (r = 0.64 and r = 0.55, respectively, p > 0.05).

Conclusions

This study validates the suitability of CBCT for periodontal assessment. Further studies are necessary to optimize the measurement methodology with CBCT.

Monday, August 14, 2017

Dentsply Sirona World 2017 selling out fast

Come and join me at this years SiroWorld! MJ
Sign up now to reserve your spot at the Ultimate Dental Meeting before it’s too late!

CHARLOTTE, N.C. (Aug. 8, 2017) – Only a limited number of registrations remain for Dentsply Sirona World in Las Vegas. With tracks including Business and Practice Management, CEREC®, Imaging, Restorative, Endodontic, Orthodontic and more, this educational festival is designed to provide the highest caliber of education to all dental practitioners, including General Practitioners and specialists.
Kicking off on Thursday, Sept. 14, and continuing through Saturday, Sept. 16, at The Venetian and The Palazzo, Dentsply Sirona World is the ultimate educational festival for dental professionals to gain comprehensive clinical and business content throughout the day and enjoy remarkable entertainment in the evening.
Registration to Dentsply Sirona World includes access to all General Sessions and Breakout Sessions, along with the social events- including the workout session with Beachbody Super Trainer Joel Freeman and the Evening of Espionage closing party at Tao Nightclub- and all of the celebrity entertainment like the exclusive concert by Grammy-winning band Imagine Dragons.
There are multiple registration types†, including doctor, staff/spouse/guest, technician, military and government, etc. Visit www.dentsplysironaworld.com for a full list of registration options and pricing.

To register now, visit www.dentsplysironaworld.com and sign up before it’s too late. For any event questions, please contact the help desk by email at events@dentsplysironaworld.com or by phone at 844.462.7476.

Friday, August 11, 2017

Effect of conventional irrigation and photoactivated disinfection on Enterococcus faecalis in root canals: An in vitro study




 Abstract

 
Aims: A study was done to evaluate the antimicrobial efficacy of sodium hypochlorite (NaOCl) and photoactivated disinfection (PAD) on Enterococcus faecalis.
 
Settings and Design: Random sampling, in-vitro study.

Subjects and Methods: Access opening and biomechanical preparation were performed on fifty freshly extracted mandibular second premolars. The specimens were sterilized; 15 μm of E. faecalis was inoculated into each canal and incubated at 36°C for 24 h. Later, specimens were randomly divided into two groups of fifty each and following procedures was carried out: (i) conventional irrigation with 2.25% NaOCl (ii) PAD using diode laser, and toluidine blue photosensitizer. Samples were collected from each canal using sterile paper points which were deposited in brain heart infusion broth, and microbiological evaluation was carried out.

Statistical Analysis Used: Student's t-test was used to find the significant difference in the reduction of colony forming unit (CFU) between the groups.

Results: The mean CFUs of the two groups showed statistically significant difference (P = 0.001). Improved antibacterial efficacy was seen with PAD group compared to conventional NAOCL irrigation.

Conclusions: NaOCl alone was not effective in eliminating E. faecalis completely from the root canals. PAD compared to conventional irrigation showed the best results in removing E. faecalis from root canals.



Balakrishna N, Moogi P, Kumar G V, Prashanth B R, Shetty NK, Rao KR. Effect of conventional irrigation and photoactivated disinfection on Enterococcus faecalis in root canals: An in vitro study. J Conserv Dent 2017;20:125-8

Thursday, August 10, 2017

Is cone beam computed tomography accurate for post-operative evaluation of implants? an in vitro study



Abstract

Objective

To evaluate the accuracy of CBCT images for bone/implant interface diagnosis in comparison to periapical radiographs.

Study Design

Titanium implants were inserted in 74 bovine rib blocks in intimate contact to the bone walls, and with a gap of 0.125 mm (simulating a failure in the osseointegration process). Periapical radiographs were taken with conventional film, and CBCT scans were acquired with i-CAT (0.2mm and 0.125mm voxel) and Kodak (0.2mm and 0.076mm voxel) units. Three examiners evaluated the images using a 5-point scale. Diagnostic accuracy was analyzed through sensitivity, specificity, and the area under the ROC curve (AUC) with 95% confidence intervals (CI). Intra- and inter-examiner agreements were analyzed through Kendall's concordance test.

Results

Intra- and inter-examiner agreements showed satisfactory results. The greatest accuracy was observed with conventional radiographs (AUC = 0.963 / CI 95% = 0.891-0.993). I-CAT 0.125mm images showed good accuracy (AUC = 0.885 / CI 95% = 0.790-0.947), with no significant difference compared to conventional radiography. Kodak images had high specificity and low sensitivity, presenting more false-negative results.

Conclusion

Conventional radiographs showed the highest accuracy for bone/implant interface diagnosis. However, CBCT scans (i-CAT 0.125 mm voxel), if available or if performed for pre-surgical assessment of another implant site, may provide similar accuracy.

Wednesday, August 09, 2017

Manual tactile sensation, digital radiograph, and multidetector computed tomography: An in vitro study.

Dutta K, Desai PD, Das UK, Sarkar S. Comparative evaluation of three methods to measure working length - J Conserv Dent [serial online] 2017 [cited 2017 Aug 5];20:76-80. Available from: http://www.jcd.org.in/text.asp?2017/20/2/76/212242   

 

  Abstract

     

Aim: Compare the measurement of working length with three different methods manual tactile sensation, digital radiography and Mutidetector computed tomography(MDCT).

Materials and Method: 40 human premolar extracted for orthodontic purpose were selected. Teeth were store in sodium chloride (0.9%) during the study. Access cavity was prepared and canal patency was seen with no 10 file in each tooth. Manually no 15 K file was inserted from access cavity until the tip was visible at the foramen, a silicon stopper was adjusted to the corresponding buccal cusp tip and the root canal length was measured. After that in each tooth with no-15 K file inserted from access cavity with stop at tip of buccal cusp until tip appear at foramen and x-ray was taken with digital radiograph (RVG,Satelac) and canal length was measured. After that all teeth are mounted in wax block,MDCT scan was done and in the scan images of teeth, root canal length is measured from buccal cusp tip to root end. After taking measurement of working length with all three methods and the data was stastically analyzed with One Way Analysis of variance (ANOVA) followed by Turkey's Test.

Results: ANOVA and turkeys test showed that there was no significant difference in the measurements by the three procedures (p>0.05).

Conclusion: Working length measurement with MDCT scan and other two conventional methods does not show significant difference in measurement. Use of newer 3D imaging technique is useful in root canal treatment for measuring working length.

Tuesday, August 08, 2017

Clinical and radiographic comparison of biodentine, mineral trioxide aggregate and formocresol as pulpotomy agents in primary molars



Abstract

Aim

To compare the clinical and radiographic success rates of three different pulpotomy agents in primary molars after 18 months.

Methods

The study was carried out with 51 primary molars of children aged 5–9 years old. The teeth were randomly assigned to the experimental or control groups. After coronal pulp removal and haemostasis, the remaining pulp tissue was covered with Biodentine® or mineral trioxide aggregate in the experimental groups. In the control group, formocresol was placed with a cotton pellet over the pulp tissue for 5 min and after removal the pulp tissue was covered with zinc oxide–eugenol (ZOE) paste. All teeth were immediately restored with reinforced ZOE base and resin modified glass-ionomer cement, and later with pre-formed metal crowns. Follow-up assessments were carried out after 3, 6, 12 and 18 months.

Results

Forty-five teeth were available for follow up at the end of 18 months. All of the available teeth for mineral trioxide aggregate and Biodentine® were clinically successful, as were 73.3% of the FC group. Radiographic success rate for the formocresol group at 18 months follow up was 73.3, 100% for mineral trioxide aggregate and 86.6% for Biodentine® group.

Conclusion

Mineral Trioxide aggregate and Biodentine® showed more favourable results than formocresol.

Monday, August 07, 2017

The Intego Treatment Center: optimally designed for preventive care and ready for the future

As part of it commitment to better, safer, faster dentistry, Dentsply Sirona is pleased to present another unique integrated solution.  The Cavitron Ultrasonic Scaling System with Steri-Mate 360 is now fully integrated in the Intego Treatment Center.

York – General scaling and periodontal debridement applications are an integral service offered by dental practices. In order to help practitioners to best set up their treatment rooms, Dentsply Sirona has expanded its existing Treatment Centers product range with an integrated preventive care concept. The Cavitron built-in ultrasonic scaling system is now available with the Intego line of Treatment Centers for fast and effective removal of even the most tenacious deposits. The Intego and Intego Pro Ambidextrous models are available in the US and offer modern dental practice everything necessary for professional dental hygiene, dental aesthetics and dental care.

Flexibility through individually configurable equipment

Intego supports a variety of treatment concepts through two different variants: Intego TS is a traditional, over the patient delivery with hanging hoses. The dentist element has a wide range of movement and the adjustable tray holder makes for a convenient work environment. Intego CS is a continental delivery system with whip arms and offers the widest range of treatment positions around the oral cavity, whether working alone or as a team.
Intego is additionally configurable with special packages and practical equipment options. For optimal patient communication, the unit can be equipped with a 22-inch full-HD monitor, and an autofocus intraoral camera.

Integrated design ideal for hygiene procedures

Intego is an excellent choice for hygiene procedures. Configuration is ergonomically and functionally adapted to preventive care treatments thanks to features such as a double articulating headrest, external device connection, multifunctional syringe, maintenance-free electric motors, LED operating lights and, coming soon, the integration of Cavitron. The Intego Pro Ambidextrous model features an integrated infection prevention system and automated cleaning functions. Ergomotion provides a synchronized movement of the patient’s spine with no readjustment of the headrest. Changing from right-handed to left-handed operation can be easily done in 15 seconds between the treatments of patients. The Carl or Hugo stools are available as ergonomic add-ons.

Ready for the future thanks to innovative design and digital interfaces

Developed at the Dentsply Sirona Innovation Center in Bensheim, Germany, Intego Treatment Centers were created as high-quality and reliable units, designed for the technical requirements of the future. A network interface in the patient chair, and USB connections in the doctor's element enable digital updates as well as the use of additional applications. New system solutions can be accessed and controlled via the comprehensive user interface on the EasyTouch touchscreen.
The Intego Treatment Centers combine modern, award-winning design available in many color variations, with compact dimensions, and a holistic infection prevention concept. Intego is optimally equipped for every clinical need while also being optimally prepared for long-term use into the future.

Friday, August 04, 2017

Immediate implant placement into posterior sockets with or without buccal bone dehiscence defects: A retrospective cohort study



Abstract

Objectives

To evaluate bone reconstruction and soft tissue reactions at immediate implants placed into intact sockets and those with buccal bone dehiscence defects.

Methods

Fifty-nine internal connection implants from four different manufacturers were immediately placed in intact sockets(non-dehiscence group, n = 40), and in alveoli with buccal bone dehiscence defects: 1) Group 1(n =  N10), the defect depth measured 3–5 mm from the gingival margin. 2) Group 2(n = 9), the depth ranged from 5 mm to 7 mm. The surrounding bony voids were grafted with deproteinized bovine bone mineral (DBBM) particles. Cone beam computed tomography(CBCT) was performed immediately after surgery (T1), and at 6 months later(T2). Radiographs were taken at prosthesis placement and one year postloading(T3). Soft tissue parameters were measured at baseline (T0), prosthesis placement and T3.

Results

No implants were lost during the observation period. For the dehiscence groups, the buccal bone plates were radiographically reconstructed to comparable horizontal and vertical bone volumes compared with the non-dehiscence group. Marginal bone loss occurred between the time of final restoration and 1-year postloading was not statistically different(P = 0.732) between groups. Soft tissue parameters did not reveal inferior results for the dehiscence groups.

Conclusions

Within the limitations of this study, flapless implant placement into compromised sockets in combination with DBBM grafting may be a viable technique to reconstitute the defected buccal bone plates due to space maintenance and primary socket closure provided by healing abutments and bone grafts.

Clinical significance

Immediate implants and DBBM grafting without using membranes may be indicated for sockets with buccal bone defects.

Thursday, August 03, 2017

Freehand Versus Guided Surgery: Factors Influencing Accuracy of Dental Implant Placement


Abstract:
Introduction: 
Patient anatomy, practitioner experience, and surgical approach are all factors that influence implant accuracy. However, the relative importance of each factor is poorly understood. The present study aimed to identify which factors most critically determine implant accuracy to aid the practitioner in case selection for guided versus freehand surgery.

Methods: 
One practitioner's ideal implant angulation and position was compared with his achieved position radiographically for 450 implants placed using a conventional freehand method. The relative contribution of 11 demographic, anatomical, and surgical factors to the accuracy of implant placement was systematically quantified.

Discussion:  
The most important predictors of angulation and position accuracy were the number of adjacent implants placed and the tooth-borne status of the site. Immediate placement also significantly increased position accuracy, whereas cases with narrow sites were significantly more accurate in angulation. Accuracy also improved with the practitioner's experience.

Conclusion: 
These results suggest tooth-borne, single-implant cases performed later in the practitioner's experience are most appropriate for freehand placement, whereas guided surgery should be considered to improve accuracy for multiple-implant cases in edentulous or partially edentulous sites.

Wednesday, August 02, 2017

Prevention of HPV-Related Oral Cancer by Dentists: Assessing the Opinion of Dutch Dental Students

Abstract

The aim of this study is to assess dental students’ opinions of the dentists’ role in primary prevention of human papillomavirus (HPV)-related oral cancer using a cross-sectional web-based survey. A questionnaire, containing questions about knowledge of HPV and oral cancer, confidence in head and neck examination and role of the dentist in preventing HPV-related oral cancer, was sent to all students of the Academic Centre of Dentistry Amsterdam (n = 912). One hundred and twenty-six (n = 126) students completed the questionnaire. Significantly, more master students (75%) than bachelor students (54.3%) were aware that HPV is a causative factor for oral cancer. Master students had more knowledge of HPV than bachelor students, but knowledge about HPV vaccination was irrespective of the study phase. The majority of dental students agreed that it is important to discuss HPV vaccination with patients. Eighty-nine percent of the students think that more education about symptoms of oral cancer will increase screening for oral cancer. Development of a protocol for screening in dental practices was considered even more important. According to dental students, dentists should discuss HPV as a risk factor for oral cancer with patients. Future dentists are willing to be involved in both primary and secondary prevention of HPV-related oral cancer. Therefore, screening for oral cancer and education about HPV vaccination should be integral elements of the dental curriculum.

Tuesday, August 01, 2017

Chlorhexidine mouthwash as an anticaries agent: A systematic review

Quintessence Int 48 (2017), No. 7  (21.06.2017)

Page 585-591, doi:10.3290/j.qi.a38353, PubMed:28555200


Objective:
To evaluate the effectiveness of chlorhexidine mouthwashes on the reduction of cariogenic bacteria on patients with moderate to high risk for dental caries.
Data Sources: A systematic review of the literature was performed using Cochrane Library, Embase, PubMed, Scopus and Web of Science. The search was limited to articles in English, Spanish, and Portuguese, published until January 2017. The research question was formulated following the PICO strategy. The risk of bias was evaluated using the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

Conclusion: 
 All the authors found statistically significant differences in Streptococcus mutans levels during and after the use of a chlorhexidine mouthwash. Although the results are suggestive, there is a clear need for the development of new studies with higher quality and with longer follow-ups, in order to assess whether the results translate into less development of dental caries and, consequently, whether or not these products should be incorporated into prevention protocols.