Wednesday, March 21, 2012

Stainless Steel Crown Aspiration During Sedation in Pediatric Dentistry

Resident: Cho

Date: 3/21/12

Author(s): Adewumi et al.

Journal: Pediatric Dentistry 30:1,2008

Type of Journal: Case Report

Purpose: Describe the aspiration of an SSC in a young child undergoing conscious sedation for restorative dental treatment.

Case Report: 5 year old boy was scheduled for four sedation appointments due to anxiety. Patient was healthy, ASA I, and airway normal. The failure of oral midazolam at the first restorative appointment prompted the use of midazolam and hydroxyzine at subsequent sedations. This combination was successful and the sedations were uneventful.

At the final appointment involving SSC’s on #I and #J, patient was given 10mg (0.6mg/kg) of midazolam with 50mg (3mg/kg) of hydroxyzine. Patient was placed in the supine position and stabilized using a Papoose Board. When removing the SSC prior to cementation, the SSC became dislodged distally behind the throat pack into the patient’s airway.

Following quick oral exam and vacuum suction, mouth prop and Papoose Board was removed. Patient was given several back slaps and Heimlich maneuver. Patient was choking, coughing, and exhibited mild expiratory wheezing with no obvious signs of respiratory distress.

The patient was escorted to the hospital’s radiology department for chest Xray. While waiting for the Xray, the patient was escorted back to the dental clinic and the SSC’s were cemented on #I and #J. The radiologist confirmed the presence of the SSC in the entrance to the right main stem bronchus. The pediatric surgeon on call was contacted and diagnostic laryngoscopy with rigid bronchoscopy was performed under GA to retrieve the SSC. The surgery was uneventful and the patient was discharged home the same day.

Assessment of the article: Good example of how a dental emergency was handled correctly. The SSC was retrieved within 2 hours of the incident. It shows that good communication with a nearby hospital is critical in ensuring an efficient response in an emergency situation. This article reinforces the use of rubber dam whenever possible and a throat pack when extracting teeth/fitting SSC’s.

Clinical Evaluation of Two Different Methods of Stainless Steel Esthetic Crowns

Resident Name: Sadler
Article Info: Clinical Evaluation of Two Different Methods of Stainless Steel Esthetic Crowns

Yucel Yilmaz DDS

Journal of Dentistry for Children-71:3, 2004

Main Purpose: Compare success rates of SSCs with an opened facing or a bonded composite veneer facing.

Methods: 18 open faced and 15 veneered crowns were placed and followed up for 18 months. Teeth were asymptomatic before placement with no endodontic treatment. They were placed on upper and lower first and second molars. Determination of which crowns to use was done by a coin toss.

Key Points:

· Open facing crowns were prepared by placing a tradition SSC, then cutting an facing away to reveal tooth structure. The exposed tooth structure was etched, bonded and and composite was placed to mask the metal.

· Veneered crowns were prepared and not placed the same visit. The crowns where roughened with a polishing disk, retention grooves were placed and a resin cement was placed over the crown. After bonding, a layer of composite was placed and cured.

· Success rate was 95% for the open faced crowns and 80% for the veneered crowns.

· One open faced failed while 3 veneered failed. Failure was described as loss of 1/3 or more of the facing.

· No statistical difference between the two techniques could be found

· All failures were on lower teeth

Assessment of Article: Okay study. They had a very small sample size and I am not at all familiar with these techniques. I don’t know what you could put on a prepped tooth while you are doing the lab procedure to add the facing. Also, I wonder how good the crowns actually look because there is still plenty of metal showing on the occlusals and linguals and if parents were actually satisfied with the treatment. I think that if you are going to go for a white posterior crown then you should probably use one that is designed for that purpose.

Repairing Preveneered Posterior SSCs

Resident: Swan
Article Title:  The Repair of Preveneered Posterior Stainless Steel Crowns
Authors: Yucel Yilmaz, et al.
Journal: Pediatric Dentistry  30(5), 2008
Main Purpose: Evaluate shear bond strength and evaluate microleakage of posterior preveneered SSCs that were repaired using two different materials.

Background: Not many published studies exist regarding preveneered SSCs, but several have reported that the facing chips regularly. One study reported no chipping after 6 months, but every crown in the study had chipped after 4 years. 

Methods:  22 of these crowns were stored in saliva for 30 days and then thermocycled. Force was applied to the occlusal surface of each crown until the original veneered surface appeared to fracture. Fracture types (adhesive, cohesive, mixed) and SBS were recorded. The crowns were then repaired using one of two methods:
1) Panavia opaque cement and Tetric flow (etch, bond, leave for 60 seconds for silanization reaction, cement, cure 40 seconds, flowable, cure 20 seconds)
2) Monopaque and Tetric Flow
20 of the crowns were subjected to SBS and dye penetration tests, and the other 2 to SEM evaluation

Significant Points: 
-NuSmile preveneered crowns used in this study.
-fractures of original veneers were cohesive or mixed only, no adhesive failures (steel to composite) 
-veneer facing made of hybrid resin composite
-Opaque cement used to mask metallic shade
-SBS values slightly higher in original preveneered group, not statistically significant
-similar dye penetration in both repair groups (~20%)
-sig difference in extent of fracture bet repaired and non-repaired groups: monopaque group had more cracking and loss of 1/3 size of crown.
-SEM evaluation showed no gaps between original materials or repair material (SS was sandblasted)
-forces required to induce fracture ranged from 763 to 870 N, which is much greater than average biting force of a 5-10 yr old (375 N)

1. both of these repair materials provided basically the same SBS when compared with the original material
2. none showed a purely adhesive failure upon fracture, indicating a good bond to the SS

Thoughts:  Since we don't use these crowns it's hard to know exactly how often this would apply clinically, but these both seem like great options for repairing these crowns in anesthetic way, which is good because parents who demand crowns like this would like to have them repaired esthetically, too. 

Clinical Success and Parental Satisfaction With Anterior Preveneered Pirmary Stainless Steel Crowns

Authors: Shah, Purvi V., BS, Lee, Jessica Y, DDS, Wright, J. Timothy, DDS, MS
Journal: Pediatric Dentistry, 26:5, 2004 391-395
Reviewed by: Fotini M. Dionisopoulos, DMD

Purpose: To evaluate the success and parental satisfaction using prefabricated resin-faced stainless steel crowns (SSCs) on anterior primary teeth

Methods: This was a retrospective cross-sectional study of 46 out of 48 teeth.
-Subjects were children ages 3-6 who were treated at the UNC faculty dental practice, treated under ideal conditions under general anesthesia
-Only resin-veneered SSCs purchased commercially by Kinder Krown were included
-Each parent/guardian provided feedback regarding satisfaction with the crowns
-Criteria for evaluation of the crowns included: 1) crown appearance, 2) shape, 3) size, 4) color and 5) durability. They were judged on a scale of 1-5 (1= very dissatisfied to 5= very satisfied)

Results: The average age of the crown at evaluation was 17.3 months.
-There was a 100% retention rate of the SSCs, with exception of 2 of the teeth exfoliated out of 48
-Overall, 24% of the crowns had some sort of facing loss: Six (13%) of the crowns had total facing loss, Five (11%) had partial facing loss due to fracturing, Seven (15%) had a loss of some incisal resin due to wear. Overall, Kinder Krowns had a better facing retention than other previously studied SSCs.
-Parental satisfaction was positive overall- especially with regard to appearance, color, shape and size.
- The parental satisfaction score was an average of 21 on a 25 point scale.
-When the factors associated with total parental satisfaction with the resin-faced SSCs were explained, the authors found that patient sex (female), overjet, and overbite were significant and had a positive relationship in the model. Significant clinical factors that had a negative effect on total parental satisfaction were: 1) facing fractures, 2) color, and 3) wear.
-Facing failure was associated with an increased overjet.
Conclusion: It is good to know that the Kinder Krown restorations are an option to protect the anterior teeth. Facing loss is definately an issue with these--it is good to let the parent know ahead of time that if this is the route that is chosen, that facing loss is likely. It would be good to see how these crowns did more than 17.5 months after and if they all lasted until the teeth exfoliated at normal exfoliation time-- I would assume there would also be a higher percentage of total facing loss.

Tuesday, March 20, 2012

Use of Anterior Veneered Stainless Steel Crowns by Pediatric Dentists

Resident’s Name: Jessica Wilson
Article title: Use of Anterior Veneered Stainless Steel Crowns by Pediatric Dentists
Author(s): Oueis et al.
Journal: Pediatric Dentistry
Year. Volume (number). Page #’s: 2010. 32:5. 413-416.

Anterior veneered stainless steel crowns (AVSSCs) have demonstrated high levels of parental satisfaction in previous studies. Both Kinder Krowns and NuSmiles have been evaluated and shown low failure rates.

849 out of 2,6000 pediatric dentists responded to a web-based survey regarding the use of AVSSCs.

456 (51%) of respondents utilized AVSSCs in their practice.
187 (41%) selected them as their first choice for full coverage primary anterior restorations while 46% preferred composite strip crowns.
278 (61%) selected the extent of caries as the influencing factor for their restoration choice.
NuSmile was the most common crown brand (61%) with Kinder Krown (35%) in second.
The major concern (73%) was crown durability with the majority of respondents recommending the manufacturers to allow crimping and improve facing retention.

Assessment of Article:
I liked this straight-forward article. The results are directly clinically applicable.

Veneer Retention of Preveneered Primary Stainless Steel Crowns After Crimping

Kyung-Hong Cal Kim

Veneer Retention of Preveneered Primary Stainless Steel Crowns After Crimping

Authors: Gupta M, Chen J, Ontiveros JC

Journal of Dentistry for Children 75:1, 2008

To determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings.

-The more esthetic options to restore primary anterior teeth (strip crowns, open-face resin crowns) tend to be the most fragile and time consuming.
-Main concerns regarding preveneered primary SSCs are long-term retention and resistance to fracture of the veneer.
-Pressure and high heat from sterilization can destroy the attached resin layer.

-26 NuSmile crowns
-13 crimped @ lingual aspect of the crowns, 13 uncrimped (control) crowns.
-Cemented onto resin cores duplicated from basic standard crown preparation on a typodont tooth #E using Ketac.
-24 hours after cementation, each specimen was placed into the custom holder on the Instron machine, and force was applied to the veneer at the veneer-crown junction at the incisal edge until the veneer fractured or was completely or partially dislodged.

-No statistically significant difference in shear strengths required to fracture the veneers or in the percentage of veneers lost upon fracture between both groups.
-The mean force required to fracture the veneers were in the range of 510 to 511N.
-Considering average biting force of 5- to 10-year-old children is around 357 +/- 64N, breakage of the veneers is probably due to traumatic forces, not incisive forces.
-Other variables include custom fabrication of each crown, variable thickness of the veneer material, operator standardization and modulus of the core material.
-One important factor contributing to the longevity of the veneer, although it wasn’t part of this study, is presence of water(moisture?), as composites tend to absorb water over an extended period of time and it could affect the strength of the bond and/or veneering material.
-Other study comparing different brands of preveneered SSCs (NuSmile, Cheng, Kinder Krown, Whiter Biter II), Whiter Biter II were significantly more resistant to shearing forces.

Even though it had many limitations as admitted by the authors themselves, this was an interesting study that attempted at answering the question all pediatric dentists probably asked themselves at least once in their careers. Even with their well-known limitations, preveneered SSCs are the treatment of choice when limited tooth structure is available after complete caries removal or if the prep extends too far subgingival. It is unfortunate that there isn’t a good enough alternative option that will be more esthetic and more retentive than preveneered SSCs that are currently available. I am sure I am not the only one whose heart skipped a beat when a child who went to the OR for “definitely negative” behavior returns for their recare visits with their NuSmiles in their moms’ hands. If and when the opportunity comes, I can’t wait to try those fancy EZ-Pedo crowns!

Parental Satisfaction with Preveneered Stainless Steel Crowns for Primary Anterior Teeth

Resident Name: Elliot Chiu

Article Info

Title: Parental Satisfaction with Preveneered Stainless Steel Crowns for Primary Anterior Teeth

Author: Cariann Champagne, DDS

Journal: Pediatric Dentistry 2007

Main Purpose

To evaluate parental satisfaction with NuSmile crowns


-54 parents completed a survey 6 months after NuSmile crowns were placed on their child

-Average age: 4 years old

-Average # crowns per patient: 5

-Total # crowns placed: 238

Key Points

-93% of parents were overall satisfied with NuSmile crowns

- Size: 97% satisfaction

-Shape: 94%

-Shade/retention: 89%

-Metal visibility: 74%

-Durability: 70%

-11% of crowns demonstrated fracture of the veneer

-<1% of crowns completely dislodged


It would be interesting to see parental satisfaction for a longer follow-up time such as 1-2 years.

Crowns from canine to canine or lateral to lateral would be the most esthetic. The author didn’t comment on the parental response being affected by how many crowns were placed or which teeth were crowned.

Parents seem very satisfied with the esthetics on these pearly white crowns. My opinion is the esthetics on strip crowns is much better, I’d be curious to see what the parents think if both could be compared side by side.

Clinical Outcomes for Primary Anterior Teeth Treated with Preveneered Stainless Steel Crowns

Resident Name: Matthew Freitas
Article Info
Title: Clinical Outcomes for Primary Anterior Teeth Treated with Preveneered Stainless Steel Crowns
Author: J. K. MacLean
Journal: Pediatric Dentistry 29:3 2007

Main Purpose
-The purpose of this study was to explore clinical outcomes for NuSmile anterior preveneered stainless steel crowns.

-1 or more NuSmile crowns were either placed by a private dentist or a pediatric dental resident on max or mand anterior teeth (cemented with glass ionomer cement).
-At least 6 months later 3 examiners assessed many factors: 1. presence; 2. chipping; 3. wear; 4. crazing; 5. margin location

-226 NuSmile crowns were evaluated; mean age of patients were 4 years 2 months.
-Each patient received on average of 5 crowns; the majority placed under general anesthesia.
-96% of the patient's NuSmile crowns were of a lighter shade that did not match their natural shade.
-85% were determined to look normal in shape and size.
-88% resisted fracture for at least 6 months.
-71% resisted attritional wear.
-99% resisted crazing.
-They found canines to be the least successful and most likely to fracture, wear and appear bulky.
-They found no difference whether the NuSmile crowns were placed by private dentist or residents :)

-Limitations of NuSmile crowns: inflexible, resin facing material tends to break, no crimping, agressive tooth preparation, expense, limited shade choice, and difficulty placing multiple crowns adjacent to one another when you have crowding or spaceloss.
-The authors argue that while bonded strip crowns are the most esthetic, they are also time consuming and extremely technique sensitive (especially when you are unable to obtain hemostasis).
-The study was slightly limited because the follow-up was approximately 6 months.

Repairing a Preveneered Stainless Steel Crown with Two Different Material

Repairing a Preveenered Stainless Steel Crown with Two Different Materials
Yucel Yilmaz, DDS, PhD; Asude Yilmaz, DDS, PhD
Journal of Dentistry for Children 71:2, 2004

Resident Meg

Abstract: To determine the bond strength of two repair materials used for a preveneered SSC after bond failure and breakage of the veneer.

16 preveneered SSC's (NuSmiles) were used. They were placed in water for one year casted on dies and cemented. The crowns were then loaded with a mechanical testing machine applying force to the veneer until the veneer fractured or dislodged. The data was recorded and the characteristics of the failure were scored.
The fractured crowns were then divided into two groups.
Group 1: NuSmile + Tetric Flow: Contour discs were used then a phosphoric acid was applied, followed by two bonding agents. Tetric flow was applied in two layers over the area.
Group 2: Nu Smile + Major Resin: Crowns were prepared using the same finish phosphoric rinse and bond. Veneering resin and it's opaquer were used brand name Opaquer.
All crowns were then stored in water again, thermocycled then debonded again with the same machine. The failures and forces were recorded.

*The Major Resin material required the least amount of force to dislodge.
*All the repaired groups demonstrated both mixed and adhesive failures.
*The extent of the fracture was either 1/3 or 1/2 of the veneer but never complete.
*Both repair groups showed modes of fracture similar to the original veneer.
*None of the repair groups showed complete facing dislodgement.

We've all seen our NuSmiles in the clinic lose a facing and it's unfortunate that there is still no real good solution to it's repair. I'd be curious to try one of these repair techniques, however, the outcome doesn't look that great. One thing it reminded me of is that we should tell our parents that with these crowns there is a strong chance that the veneer will break and there are no good repair techniques so they are prepared for when it does break.

Wednesday, March 14, 2012

Long-term Photographic and Radiographic Assessment of Bonded Resin Composite Strip Crowns for Primary Incisors: Results After 3 Years.

Kyung-Hong Cal Kim

Long-term Photographic and Radiographic Assessment of Bonded Resin Composite Strip Crowns for Primary Incisors: Results After 3 Years.

Authors: Kupietzky A, Waggoner WF, Galea J

Pediatric Dentistry 27:3, 2005

To examine the photographic and radiographic success of the treatment of maxillary anterior primary incisors with composite resin strip crowns (SCs) placed in a private-practice setting after a minimum of 18 months.

-Retrospective study (145 restorations in 52 children, with average age of 31.3 months)
-Private practice in middle- and upper-class preschool children
-Extensive caries on 1 surface, moderate caries on 2+ surface, or traumatized incisors with crown fractures involving at least 1/3 of the clinical crown: more than 1/2 to 2/3 of the clinical crown must be in tact to ensure sufficient surface area for bonding
-None were placed under GA
-Photographs were taken to for evaluation of gingival health and clinical appearance by 2 independent raters
-Radiographic success was defined as the absence of pathologic internal/external root resorption, or periapical radiolucency

-88% showing no discernable difference in color with adjacent teeth
-98% w/ acceptable or ideal contour
-20% rated as having lost some resin material
-99% w/ no gingival inflammation (43%) or mild marginal gingivitis (56%)
-89% w/ nice, continous crown contour (54%) or slight overhang or an area of RL at the margin (35%)
-92% w/ healthy pulps, while only 6% had pulpal changes (premature resorption, calcific metamorphosis, and internal resorption.

-Less-than-ideal crown margins or its cervical plaque retention make gingiva surrounding SCs twice as more likely to show gingival inflammation than gingiva surrounding unrestored adjacent teeth.
-With good retention rate (83% after 1.5 years and 78% after 3 years) and ability to maintain good pulpal health (93%), SCs can be considered a very good treatment of choice if adequate tooth structure remains after caries removal. Prevaneered SSC should be considered if caries removal results in insufficient tooth surface area for bonding

Good article, although as the author pointed out there are many limitations to this study. The results from this study are very similar to what we see in the clinic, and the conclusion that recommends SCs for teeth with sufficient tooth structure and Nu-Smiles for those without is what we usually do either in the clinic or in the OR. Based on my experience in the clinic, I agree with the article that gingival inflammation seems to be the major issue with the strip crowns post-operatively, and unfortunately, patients who need strip crowns are less likely to maintain good oral hygiene after the teeth are restored.

Evaluation of Resin Based and Glass Ionomer Based Sealants Placed With or Without Tooth Preparation

Resident Name: Elliot Chiu

Article Info

Title: Evaluation of Resin Based and Glass Ionomer Based Sealants Placed With or Without Tooth Preparation

Author: Vineet Dhar, BDS, MDS, PhD

Journal: Pediatric Dentistry Jan/Feb 2012

Main Purpose

-To compare the 2 year success of 2 sealants placed with and without tooth prep.


-25 children 6-10yo had 4 6-year molars sealed using rubber dam isolation by 1 operator

-Split mouth design used, teeth randomly selected to be sealed with a resin sealant (Clinpro) or GI sealant (Fuji VII), with or without tooth preparation

-Teeth prepared using a quarter round bur on a slow-speed handpiece

-Teeth evaluated every 6 months for 2 years

Key Points

-Resin sealants showed better retention than GI sealants

-100% loss of retention was seen in teeth sealed with GI sealants without prep

-Tooth prep improved the retention of sealants in both types

-In cases of sealant loss, tooth preparation made the teeth more prone to caries

-In cases of sealant loss, teeth sealed with resin sealants were more prone to caries than teeth sealed with GI sealants


-I was surprised that ALL GI sealants without prep fell off after 2 years

-If you prep the tooth before, it helps with the retention. But if the sealant falls off, the tooth is now more prone to caries.

Multi-colored Duel-cured Compomer

Resident’s Name: Jessica Wilson
Article title: Multi-colored Duel-cured Compomer
Author(s): Croll et al.
Journal: Pediatric Dentistry
Year. Volume (number). Page #’s: 2004. 26:3. 273-276.

To detail the procedure for use of MagicFil compomer material for occlusal restoration of a primary second molar.

MagicFil, a polyacid-modified resin-based composite (compomer), is a dual-cured material that is produced in Blue, purple, yellow, “universal” and a green color can be developed by mixing yellow and blue. Although MagicFil is meant to be decorative, it displays physical properties that “apparently are sufficient to hold up in the mouth until the restored primary tooth is lost.” However, the properties do not match those of traditional resin based composites and long-term durability will vary. The authors have only placed MagicFil in Class I, II and V restorations in teeth that will exfoliate in 3-5 years.
The authors note that since the compomer contains glass filler particles, once the material is saturated with saliva, fluoride ion is released and available for take-up by nearby tooth structure, however, more research needs to be done in this area.

The use of anesthetic, RDI, etch and bond is recommended in the usual manner. In the case of the class II restoration, a matrix band and wedge should be used. The material is placed with a double-barrel mixing syringe and should be added in 1-1.5mm thick layers and cured for 30 seconds with each new layer. Usually 2 increments is sufficient in primary teeth. A final layer of sealant material can be placed to fill “marginal microgaps”. Occlusion should be checked and adjusted if needed.

Assessment of Article:
The authors report having no financial interest in the product or company and I thought it was an interesting presentation of a material that I don’t believe many of us have had the opportunity to work with. The longest follow-up included in this article was 1 year so I would be interested to see an update in the long term use of this material. Not sure if I really buy into it at this point, but this might be where pediatric dentistry is headed in the near future!
PS. See you guys next week!!

Tuesday, March 13, 2012

Microshear bond strength of resin composite to teeth affected by hypomineralization using 2 adhesive bonding systems

Resident Name: Sadler
Article Info: Microshear bond strength of resin composite to teeth affected by hypomineralization using 2 adhesive bonding systems

Vanessa William BDS

Pediatric Dentistry 28:3, 2006

Main Purpose: Evaluate bond strength in hypomineralized molars compared to healthy enamel using two different bonding systems.

Methods: 120 first permanent molars from children under 18 years of age were collected. Teeth were ground to a flat surface and were bonded with either 3M single bond or 2 step bond Clearfil SE. A tube of composite was attached and cured. Samples were evaluated to strength by a shear test. Some samples were evaluated by SEM as well

Key Points:

· 22 control surfaces of regular enamel and 27 surfaces of hypomineralized enamel were used for each bonding agent

· Shear strength was significantly higher on the control enamel than on the hypomineralized enamel.

· No statistical difference could be found in the shear strength of either adhesive in hypomineralized enamel.

Assessment of Article: I was not a fan of the article. I thought that the conclusions they reached were already fairly obvious and it was well understood that bond strength in hypomineralized enamel was weaker. It was VERY technical in describing lab processes. It also threw in some SEM photos that described different etch patterns that turned out to not matter because the bond strength was essentially the same. I guess what I can gather as the take home is that these alternative bonding systems may be worth trying just to see what they are like.