Wednesday, May 27, 2015

ineral Trioxide Aggregte versus formocresol in pulpotomized primary molars: a preliminary report

Anna Abrahamian
June 3, 2015
Title: Mineral Trioxide Aggregte versus formocresol in pulpotomized primary molars: a preliminary report
Authors: Eliezer Eidelman, DrOdont, MSD, et al.
Journal: Pediatric Dentistry, Volume 23 (1)
Date: 2001
Purpose: The aim of this study was to compare the effect of mineral trioxide aggregate (MTA) to that of formocresol (FC) as pulp dressing agents in pulpotomized primary molars with carious pulp exposures.
Methods: Forty-five primary molars of 26 children were treated by a conventional pulpotomy technique. The teeth were randomly assigned to the MTA (experimental) or FC (control) group by a coin toss. Following removal of the coronal pulp and hemostasis, the pulp stumps were covered with an MTA paste in the experimental group. In the control group, FC was placed with a cotton pellet over the pulp stumps for 5 minutes and removed; the pulp stumps were then covered by zinc oxide-eugenol (ZOE) paste. The teeth of both groups were restored with stainless steel crowns. Eighteen children with 32 teeth arrived for clinical and radiographic follow-up evaluation ranging from 6 to 30 months.
Results: The follow-up evaluations revealed only one failure (internal resorption detected at a 17 month post-op evaluation) in a molar treated with formocresol. None of the MTA-treated teeth showed any clinical or radiographic pathology.  Pulp canal obliteration was observed in 9 of 32 (28%) evaluated molars. This finding was detected in 2/15 teeth treated with FC (13%) and in 7/17 treated with MTA (41%).
Conclusions: MTA showed clinical and radiographic success as a dressing material following pulpotomy in primary teeth and seems to be a suitable replacement for formocresol in primary teeth.

Tuesday, May 26, 2015

Microleakage of a new improved glass ionomer restorative material in primary and permanent teeth.

Microleakage of a new improved glass ionomer restorative material in primary and permanent teeth.
Authors: Castro A et. al.
Classic 100: Article #6 - Pediatric Dentistry 2002
Resident: Margaret Maclin

Purpose:
To assess the microleakage of the new conventional GI, Fuji IX in comparison to another conventional GI, an RMGI, and a composite resin in primary and permanent teeth

Background Information:
ART (Atraumatic Restorative Treatment)
- “Strategy of care using chemically cured, intermediate restorative materials in countries where children do not have access to optimal care.”
- Caries removal using hand instruments only + GI restorative material w/ adhesive characteristics
Glass Ionomer
- Advantage: chemical adhesion to dentin and enamel, fluoride release, high tissue tolerance, and pulpal biocompatibility
- Disadvantage: Lack of strength, abrasion resistance and poor esthetics

Improvement of recent years is largely due to smaller mean particles

Methods:
- 25 extracted premolars and 13 primary molars were randomly divided into 5 subgroups
- New Conventional GI (Fuji IXgp)
- Conventional GI (Fuji II)
- RMGI (Vitremer)
- Composite resin (TPH)
- New Conventional GI (Fuji IXgp) w/o conditioner
- Saucer-shaped cavity, 3.0mm in diameter and 1.0mm deep prepared in each tooth
- Teeth in each subgroup were then restored following manufacturer’s instructions
- 50% aqueous solution of silver nitrate for two hours in darkness, then placed in the developer for 8 hours under fluorescent light
- Sectioned teeth (2x in permanent, 3x in primary) and results were recorded

Results and Discussion:
- Microleakage in primary teeth: Fuji II (45%) > Fuji IX w/o conditioner (42%) > Fuji IX (24%) > TPH (16%) > Vitremer (9%)
- Microleakage in permanent teeth: Fuji II (76%) > Fuji IX w/o conditioner (46%) > Fuji IX (29%) > Vitremer (13%) > TPH (6%)
- Microleakage was observed more in primary teeth when restored w/ TPH
- Microleakage was observed more in permanent teeth when restored w/ Fuji II
- When conditioner was used, Fuji XIgp behaved similarly to RMGI or composite resin

Characterization of resin composites polymerized with plasma arc curing units



Authors: A. Peutzfeldt, etl al.

Journal: Academy of Dental Materials

Purpose: To determine a number of characteristics of resin composites polymerized by plasma arc curing units

Background: Plasma arc curing (PAC) unit lights emit light from a glowing plasma composed of a gaseous mixture of ionized molecules and electrons. PAC units are characterized by a very high output in a rather narrow range of wavelengths around 470 nm.

Methods: Two PAC units (Apollo 95E and 1000 PAC) were investigated and a halogen curing unit (XL 3000) was used as baseline. The investigated polymerization characteristics of the materials were: 1.) quantity of remaining double bonds 2.) depth of polymerization 3.) flexural strength and flexural modulus 4.) wall-to-wall polymerization contraction

Results: Irradiation with Apollo 95E resulted in a higher quantity of remaining double bonds than did XL 3000, whereas the results obtained with 1000 PAC depended on the resin composite. The depth of cure with plasma arc units was equal to or less than that obtained with the conventional unit, dependent on the resin composite. The flexural strength did not depend on the curing unit. The flexural modulus resulting from curing with Apollo 95E was less than curing with XL 3000. The wall-to-wall polymerization contraction was equal to or less with the plasma arc units than with the conventional unit.


Conclusion: Plasma arc curing units make it possible to polymerize resin composite in much shorter times than conventional curing units, but the polymerization characteristics associated with the PAC units may be less than optimal.

Review of monitors and monitoring during sedation with emphasis on clinical applications

Anna Abrahamian
May 26, 2015

Article Title:  Review of monitors and monitoring during sedation with emphasis on clinical applications

Author: S Wilson, DMD, MA, PhD

Journal:  Pediatric Dentistry, Volume 17(7): 413-418

Date: 1995

·      Prior to 1980’s, only two papers reported the recording of physiologic measures during sedation
·      In the early 1980’s, electronic monitors began to flood the market, likely due to the development of the microchip, enabling the monitors to be packaged in smaller/more convenient units.
·      Pulse Oximetry: considered the “gold standard” for monitoring.
o   Measures the oxygen saturation and heart rate via an oxisensor
o   The oxisensor contains two elements: one emits light in red and infrared wavelengths and the other detects light transmitted through tissue.
o   Oxygenated hemoglobin absorbs more red wavelengths of light while deoxygenated hemoglobin absorbs proportionately more infrared.
o   Patient movement, red nail polish, crying involving Valsalva maneuver, blood pressure cuff on same extremity, and straining against wraps of a papoose board can cause erroneous readings
·      Blood Pressure Cuffs
o   Automated BP cuffs indicated indirectly the systolic and diastolic blood pressures, as well as heart rate
o   Artifact information can be caused by: cuff too large or small, air leaks within the system, and patient movement.
o   Under normal circumstances, most automated BP cuffs require less than 30 sec to determine BP.
o   In a struggling child, prolonged inflation can cause pain, which aggravates behavior.
o   It has not been determined if baseline BP is of any clinical value in the uncooperative, but otherwise healthy patient
·      Capnography
o   Least understood, least utilized, and only monitor that can give an indication of airway patency.
o   Determines expired CO2 concentration by infrared sensor.
o   Single breath excursions are displayed which represent the concentration of expired carbon dioxide during he expiratory cycle of breathing
o   Classified as mainstream (units used in intubated patients) or side-stream (units that are appropriate for non-intubated, sedated patients)
o   Most capnographs have an alarm to indicate an obstruction
§  Mucous blockage, crying, and mouth breathing may set off the alarm due to detection of lower expired CO2
§  **Meperidine causes the rise and fall segment of each single excursion to waver slightly because it causes increased tension in the respiratory muscles during expiration.
·      In a non-sedated patient, expiration involves a passive relaxation of the elastic tissues and little muscle involvement.
§  When a patient has received a narcotic like meperidine, the carbon dioxide concentration in the body tends to increase slightly over time due to mild depression of the respiratory centers
§  Normal carbon dioxide concentrations in children range from 33-40 mm Hg.
·      Precordial Stethoscopes
o   Useful for monitoring airway and heart sounds during sedations
o   Imaginary triangle with base formed by line drawn between the nipples with the apex formed by the remaining sides each joining the nipple to the precordial notch at the junction of the neck and chest.
o   Bell of stethoscope should be placed at the apex of the triangle in order to hear breath sounds


Effect of 1.23% acidulated phosphate fluoride (APF) gel on fluoride-releasing restorative materials.

05/27/2015

Article: Effect of 1.23% acidulated phosphate fluoride (APF) gel on fluoride-releasing restorative materials.

Authors: Cehreli et al.

Journal: Journal of Dentistry for Children, 2000

Purpose: The study evaluated the effect of 1.23% APF gel on surface morphological characteristics and surface roughness of 1 high viscosity glass ionmer cement (HVGIC), 3 polyacid-modified resin based composites (PMRC) and 2 resin modified glass ionmer cements (RMGICs).

Background:
Some studies have shown degradation in RMGICs and PMRCs when treated in vitro by immersion in home-use of 0.5% APF gel over a long period of time.

Methods:

·      Plexiglass disks were used to make the specimens. A total of twenty specimens per material were used. 10 were the test and 10 were the control specimens.
·      After light curing the specimens were placed in 37 degrees Celsius deionized water for twenty-four hours.
·      Recommended manufacturer varnish was then applied.
·      Sequential polishing of material done after 24 hours.
·      Before APF treatment specimens were stored in 37 degrees Celsius.
·      Test specimens were then exposed to APF gel with cotton applicator for a period that simulated 4 years (1 min/6 months) under prophylactic fluoride treatment.
·      Control specimens were stored in distilled water.
·      Average surface roughness of the control and treated specimens were measured.

Results:
·      After APF treatment there was a statistically significant increase in surface roughness.
·      PMR material displayed the highest surface roughness value.
Conclusion:
·      Increasing surface roughness through APF treatment can increase the surface roughness of some cements which could harbor S. Mutans.

·      Additional study in needed to determine the effects of APF agents on mechanical properties of dental materials.

Microleakage Evaluation of Restorations Prepared with Air Abrasion


Title: Microleakage Evaluation of Restorations Prepared with Air Abrasion
Author: Guirguis et al.
Journal: Pediatric Dentistry 1999

Background: Air abrasion utilizes kinetic energy from alumina particles propelled by an air stream (Kinetic Cavity Preparation). The effects of air-abrasion cavity preparation on human enamel and dentin has been investigated under scanning election microscopy. When compared to high speed burs, air abrasion produced rounded margins and uniform abrasion with less stress, microchipping , and cracking. Other studies explored effects on bonding of restorative materials to enamel and dentin, pulpal response, dentin permeability, and to a lesser degree, microleakage.

The manufacturers of air-abrasive devices claim that their use reduces or eliminates the need for acid etching. The microleakage that may result following air-abrasion tooth preparation is unknown.

Purpose: The objective of the study was to measure and compare microleakage around preventative resin restorations prepared conventionally or with air-abrasion in the presence or absence of Acid etching.

Methods: One hundred extracted human non carious molars were assigned to each of four groups. Group A: fissures opened with a high speed handpiece, etched and restored with composite and sealants. 
Group B: fissures opened with KCP 1000 and restored with composite and sealants. 
Group C: fissures opened with KCP 1000, etched, and restored with composite and sealants. 
No adhesive was used for groups A, B, or C. 
Group D: fissures opened with KCP 1000, adhesive resin was applied, cured and restored with composite sealant. All teeth were thermocycled, stained with silver nitrate, sectioned and viewed with a computer linked measuring microscope. Measurements were recorded in a relative percentages and absolute millimeters.

Results: T-test showed no statistical significance between groups A and C, or between B and D. Statistically significant differences were found among groups A and B, groups A and D, groups B and C. and groups C and D.

Conclusions:
·      Significant microleakage was observed in all non-etched specimens prepared with air abrasion.
·      A minimal degree of microleakage was observed in all acid etched specimens prepared with either air-abrasion or conventional technique
·      The application of adhesive resin did not reduce microleakage in specimens treated with air-abrasion alone
·      If air-abrasion is used, it should be used in conjunction with acid etching.
·      The findings of this study do not support the manufacturers claims which state that the use of air abrasion reduces or eliminates the need for acid etching.