Martha Brackett | Augusta University (original) (raw)

Papers by Martha Brackett

Research paper thumbnail of Clinical Evaluation of the Soft-Start (Pulse-delay) Polymerization Technique in Class I and II Composite Restorations

Operative Dentistry, 2008

The polymerization shrinkage of resin composites may affect restoration quality. A double blind, ... more The polymerization shrinkage of resin composites may affect restoration quality. A double blind, randomized clinical trial was carried out to compare two curing techniques-Soft-Start (SS) and the plasma arc curing light (PAC). The hypothesis that, delaying the gel point (with SS) improves marginal seal, was tested at alpha = 0.05. Also, this report includes two-week, three-month, one-year and two-year results for post-op sensitivity. Twenty informed participants, each needing two Class II and/or complex Class I restorations, gave written consent. All the teeth were trans-illuminated to rule out pre-op crack lines before restoration placement. Fifty Z100-Single Bond restorations (25/SS and 25/PAC) were placed under rubber dam. Protocols: PAC (Control)-incremental curing < 2.0 mm, 2000 mW/cm2 for 10 seconds for all layers, SS (Treatment)-incremental curing <2.0 mm, 600 mW/cm2 for 20 seconds, except the final layer or enamel replacement increment, which was cured as follows-(mW/cm2/time) 200/3 seconds, wait 3 minutes; 200/3 seconds, wait 5 minutes; 600/20 seconds from multiple angles. Sensitivity to a standardized cold stimulus was performed preoperatively at 2 weeks and at 3, 12 and 24 months. Patients rated their sensitivity after stimulus by means of a Visual Analog Scale (VAS). In addition, two independent, calibrated investigators evaluated the restorations clinically at each appointment. There were no significant differences in VAS scores between the two groups at any appointment period (two-way ANOVA; p > 0.05). Several conditions were defined as indicating marginal stress before the start of the trial. At 24 months, there was no significant difference between the SS and PAC groups. Within the limitations of this study, Class I and II restorations placed with a SS technique did not show significant changes in post-op sensitivity or decreased signs of marginal stress.

Research paper thumbnail of Postoperative Sensitivity: A Comparison of Two Bonding Agents

Operative Dentistry, 2007

Historically, postoperative pain associated with temperature was considered a thermal conduction ... more Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent. This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared. For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American Journal of Dentistry, Feb 1, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity recorded. The difference in sensitivity between the two products proved to be statistically significant (Chi-square analysis, P < or = 0.0001). The median shade change for both products following 2 weeks of active treatment was six tabs. At the 4-week evaluation, the median shade change was 5.5 and 6.0 tabs respectively for Rembrandt and Nite White. There was no statistical difference between the products in respect to shade change.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...

Research paper thumbnail of Effect of Restoration Size on the Clinical Performance of Posterior “Packable” Resin Composites Over 18 Months

Operative Dentistry, 2007

Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restor... more Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restorations were placed in molars under rubber dam isolation. The restorative systems used were: Alert Condensable (Jeneric/Pentron) and SureFil (Dentsply/Caulk). The restorations were classified according to size, with 7 small, 25 moderate and 18 large, of which 8 were cusp replacement restorations. Baseline, 6, 12 and 18-month double-blinded clinical evaluations were carried out using modified USPHS criteria. The independent variables: restorative material, restoration size and three other clinical factors, were tested using a Multiple Logistic Regression procedure to determine if any were predictive of failure. Of the 50 restorations, four failed by the 18-month recall, three failed due to fracture of the restoration and one due to secondary caries. Both restorative systems demonstrated a 92% success rate. No association between restoration size (p = 0.99) or restorative material (p = 0.65) and failure was found. Similarly, the additional variables, occlusal contact type, presence of occlusal wear facets and first or second molar, were not predictive of failure.

Research paper thumbnail of A Comparison of Human Raters and an Intra-oral Spectrophotometer

Operative Dentistry, 2009

Consistently choosing an accurate shade match is far more difficult than it appears. Recently, se... more Consistently choosing an accurate shade match is far more difficult than it appears. Recently, several electronic shade-matching devices have been marketed. One device is an intraoral spectrophotometer, Easyshade. The current study compared the accuracy and consistency of the Easyshade (ES) device to three clinicians experienced in tooth whitening trials and trained in the use of the Vitapan 3D Master shade. The maxillary anteriors of 16 participants were matched on three separate occasions one month apart. At each appointment, the three clinicians (R1, R2 & R3) and ES independently chose a single 3D Master tab. A trained research assistant used the Easyshade device to record CIE L*, C* and H* and a shade tab. In addition, color differences between shade tabs were calculated using the Delta E 2000 (delta e 00) formula. The CIE L*C*H* data were also used to establish standards for the five lightness groups of the 3D Master. An intrarater agreement was evaluated using an intraclass correlation statistic, and an inter-rater agreement was evaluated using a weighted Kappa statistic. The percentages of exact matches were: ES = 41%; R1 = 27%; R2 = 22% and R3 = 17%. Matches within a half-shade were also calculated. This represents a mismatch that is perceptible but acceptable. The percentages of matches within a half-tab were: ES = 91%; R1 = 69%; R2 = 85% and R3 = 79%. In terms of lightness, the intra-rater agreement was considered to be very good for ES and R2 and good for R1 and R3. For chroma, agreement for ES was considered good, and for the three clinicians, it was considered moderate. The mean color difference for the L*, C*, H* data recorded at each evaluation was 1.5, or only slightly greater than the color difference between the same tab on different guides (1.2). The delta e 00 data were the most accurate data collected, and they were used to establish a standard to which the tab choices of the four raters were compared. A weighted Kappa statistic was performed and, in terms of lightness, agreement was found to be good for all raters. For chroma, agreement was very good for ES and it was good for the clinicians. In terms of the number of exact matches and matches within a half-shade, the performance of ES was at least comparable to, if not better than, the dentists. Statistically, the same was true in terms of consistency and accuracy when making repeated matches of lightness and chroma using the 3D Master shade guide.

Research paper thumbnail of Comparison of Traditional and Low Sensitivity Whiteners

Operative Dentistry, 2008

This placebo-controlled, double-blind randomized clinical trial compared five 10% carbamide perox... more This placebo-controlled, double-blind randomized clinical trial compared five 10% carbamide peroxide tooth whitening formulations. Three products contained varying concentrations of potassium nitrate as desensitizers. One contained no desensitizers and one was a placebo. During the two weeks of active bleaching, participants used a daily diary to record the number of days of sensitivity from hot, cold, gums, tongue and/or throat. The total number of days of sensitivity experienced by the participants in each group was compared. Participants using the agent with no desensitizers did not experience any more sensitivity than those using the agent containing 3% potassium nitrate. The products that included 0.5% potassium nitrate and 0.5% potassium nitrate and 0.25% sodium fluoride were not associated with any more sensitivity than the placebo group. In addition, the shade tab change from baseline to 11 weeks following cessation of bleaching was compared. Using an active bleaching agent, no difference in color change was noted among the four groups. All four groups were associated with significantly higher color change than the placebo. The addition of a small percentage of potassium nitrate to a 10% carbamide peroxide tooth whitener was shown to significantly reduce postoperative sensitivity without reducing efficacy.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...

Research paper thumbnail of The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

Operative Dentistry, 2007

This study evaluated the amount of residual yellow in cured resin composites when polymerizing wi... more This study evaluated the amount of residual yellow in cured resin composites when polymerizing with either a quartz-tungsten-halogen (QTH) or blue light-emitting diode (LED). Twelve shades (bleaching to conventional shades) of microfill, hybrid and microhybrid resin composite specimens (n = 10) were polymerized with both light types. All the materials contained only camphorquinone as the photoinitiator. After exposure, the specimens were stored in the dark for 24 hours. Then, the specimen color parameters were recorded (L*, a*, b* and C*(ab)) and color differences (deltaE*(ab)) were determined by examining for changes among the test combinations. Group comparisons were examined using ANOVA and the Tukey-Kramer post-hoc test, and pairwise comparisons were made using the Student's t-tests at a pre-set alpha of 0.05. When a significant difference in the shade of yellow was noted, the QTH light produced a greater yellow tinge than most comparisons using the LED. The potential for producing more residual yellowing could not be anticipated with respect to composite filler classification or shade, as this effect may be more dependent on individual product composition. The extent to which residual yellowing differences were noted between light curing units fell within levels considered detectable by the human eye (deltaE > 2.0). The selection of light curing unit to polymerize resin-based restorative materials can have a significant influence on the amount of residual yellow present, with the QTH light tending to leave more yellow than an LED unit.

Research paper thumbnail of Postoperative Sensitivity: A Comparison of Two Bonding Agents

Operative Dentistry, 2007

Historically, postoperative pain associated with temperature was considered a thermal conduction ... more Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent. This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared. For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

Research paper thumbnail of Color differences: Polymerized composite and corresponding Vitapan Classical shade tab

Journal of Dentistry, 2009

This study compared newer composite resin restorative materials to the Vitapan Classical tabs the... more This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

Research paper thumbnail of Class II restoration combining a low-shrinkage composite and a centripetal technique

Research paper thumbnail of Penetration of fluids into periodontal pockets using a powered toothbrush/irrigator device

The Journal of Contemporary Dental Practice, Jan 7, 2006

This study was a single-blind, randomized, controlled clinical trial. The researchers evaluated a... more This study was a single-blind, randomized, controlled clinical trial. The researchers evaluated a powered brush/irrigating device (HydraBrush Oral Health System; OHS) for its safety and ability to deliver a solution to the bottom of 5-6 mm pockets, compared to rinsing alone with a solution following brushing with a powered toothbrush (Sonicare Elite 7800; SE). An evaluation technique to measure the quantity and quality of solution able to enter the pocket was also introduced in this project.METHODS: Subjects were randomized in one of two-groups: brush plus simultaneous irrigation (OHS) versus brush plus rinsing (SE). Subjects used their devices at home for two weeks. At the measurement visit, subjects used the OHS to irrigate and brush simultaneously for 1 minute (30 seconds per each side of the mouth) with a 0.01% erythrosine disclosing solution in 10 oz of distilled water. Control subjects brushed for 2 minutes with a SE followed by a 1 minute rinse with an identical disclosing solution. A blinded evaluator collected six samples of approximately of 1 microL of sucular fluid from six 5-6 mm evaluation sites. This was accomplished by inserting a microcapillary tip with a 20 microL micropipette in the sulcus. Two-group repeated measures ANOVA was used to examine differences in two measures of the disclosing solution between OHS and SE subjects; the spectrometer reading of the disclosing solutions, and by visual inspection of the samples (positive/negative) to determine the presence or absence of solution in the samples. Subjects' diaries were collected. Bleeding and discomfort during the evaluation period was reported.RESULTS: Visually, OHS had a significantly greater proportion of solution taken from the base of 5-6 mm sites than the SE (p=0.0001). However, there was no statistical difference between the two groups (p=.1359) in the spectrophotometer readings.CONCLUSION: The experimental device is more efficient in delivering a solution to the base of 5-6 mm pockets than rinsing following use of a control powered toothbrush. Both devices have demonstrated they are safe and well accepted by patients. The technique developed provides a useful method for quantitative and qualitative studies of solutions from the base of periodontal pockets.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American Journal of Dentistry, Feb 1, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity recorded. The difference in sensitivity between the two products proved to be statistically significant (Chi-square analysis, P < or = 0.0001). The median shade change for both products following 2 weeks of active treatment was six tabs. At the 4-week evaluation, the median shade change was 5.5 and 6.0 tabs respectively for Rembrandt and Nite White. There was no statistical difference between the products in respect to shade change.

Research paper thumbnail of Two-year clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material

Operative Dentistry

This study compared the clinical performance of a polyacid-modified resin composite and a resin-m... more This study compared the clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material over two years. Thirty-four pairs of restorations of Compoglass and Fuji II LC were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. A significantly higher incidence of failed restorations was found with the polyacid-modified resin composite (p < 0.05).

Research paper thumbnail of Two-year clinical performance of Class V resin-modified glass-ionomer and resin composite restorations

Operative Dentistry

While a one-year report had been previously published, this study was undertaken to evaluate the ... more While a one-year report had been previously published, this study was undertaken to evaluate the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over two years. Thirty-seven pairs of restorations of FujI II LC and Z 250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. No statistically significant difference (p = 0.13) was observed in the overall performance of the materials. Retention was 96% for the resin-modified glass ionomer and 81% for the resin composite, with no additional restorations of either material lost after one year. As previously reported, retention of the Z 250 restorations at six months was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. The resin composite restorations generally had a better appearance, with a 100% alpha rating in color match, versus 85% for the resin-modified glass ionomer.

Research paper thumbnail of One-year clinical performance of a resin-modified glass ionomer and a resin composite restorative material in unprepared Class V restorations

Operative Dentistry

This study evaluated the clinical performance and appearance of a resin-modified glass ionomer an... more This study evaluated the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over one year. Thirty-seven pairs of restorations of Fuji II LC and Z250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline and 6 and 12 months, using modified Ryge/USPHS criteria. No significant difference (p>0.05) was observed in performance of both materials, although retention of the Z250 restorations was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. Little difference in the restorations' appearance was observed.

Research paper thumbnail of 8-week Cytotoxicity of Contemporary Endodontic Sealers In Vitro

Objectives: Contemporary endodontic sealers are distinct from traditional sealers used with gutta... more Objectives: Contemporary endodontic sealers are distinct from traditional sealers used with gutta percha for canal obturation. The long-term biocompatibility of these sealers is critical to peri-apical healing, but has not been adequately defined. We assessed responses of fibroblasts and osteoblasts to contemporary sealers that were aged' for up to 8 wk. Methods: AH-plus Jet (AH), two versions of Endo Rez (Rez, ExRez), Epiphany (Eph), and traditional Pulp Canal Sealer (PCS) were mixed according to manufacturers' directions and formed into discs (n = 6). MC3T3 mouse osteoblasts, ROS 17/2.8 rat osteoblasts, and L929 mouse fibroblasts were exposed to the sealers for 72 h initially or after the specimens had been placed in phosphate-buffered saline for 4 or 8 wk. Cellular response was assessed using mitochondrial succinate dehydrogenase (SDH) activity (MTT method) by normalizing to Teflon control materials. The cellular responses to the materials were compared using ANOVA with T...

Research paper thumbnail of Eighteen-month clinical performance of a self-etching primer in unprepared class V resin restorations

Operative Dentistry

This study evaluated the clinical performance of unprepared Class V resin composites, placed usin... more This study evaluated the clinical performance of unprepared Class V resin composites, placed using a self-etching primer and a single-bottle adhesive, over a period of 18 months. Thirty-eight pairs of restorations of Renew hybrid resin composite (BISCO, Inc) were placed using adhesives from the same manufacturer in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 76% of these lesions was considered to be sclerotic. The restorations were placed without abrasion of tooth surfaces, except for cleaning with plain pumice. One of each pair was placed using Tyrian, a self-etching primer and the other was placed using One-Step, a single-bottle adhesive placed after acid etching. Both the etchant and self-etching primer were applied for 20 seconds. The restorations were clinically evaluated at baseline, 6, 12 and 18 months, using modified Ryge/USPHS criteria. For both adhesives, very low retention of 50% to 56% of the restorations was observed ove...

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...

Research paper thumbnail of Clinical Evaluation of the Soft-Start (Pulse-delay) Polymerization Technique in Class I and II Composite Restorations

Operative Dentistry, 2008

The polymerization shrinkage of resin composites may affect restoration quality. A double blind, ... more The polymerization shrinkage of resin composites may affect restoration quality. A double blind, randomized clinical trial was carried out to compare two curing techniques-Soft-Start (SS) and the plasma arc curing light (PAC). The hypothesis that, delaying the gel point (with SS) improves marginal seal, was tested at alpha = 0.05. Also, this report includes two-week, three-month, one-year and two-year results for post-op sensitivity. Twenty informed participants, each needing two Class II and/or complex Class I restorations, gave written consent. All the teeth were trans-illuminated to rule out pre-op crack lines before restoration placement. Fifty Z100-Single Bond restorations (25/SS and 25/PAC) were placed under rubber dam. Protocols: PAC (Control)-incremental curing < 2.0 mm, 2000 mW/cm2 for 10 seconds for all layers, SS (Treatment)-incremental curing <2.0 mm, 600 mW/cm2 for 20 seconds, except the final layer or enamel replacement increment, which was cured as follows-(mW/cm2/time) 200/3 seconds, wait 3 minutes; 200/3 seconds, wait 5 minutes; 600/20 seconds from multiple angles. Sensitivity to a standardized cold stimulus was performed preoperatively at 2 weeks and at 3, 12 and 24 months. Patients rated their sensitivity after stimulus by means of a Visual Analog Scale (VAS). In addition, two independent, calibrated investigators evaluated the restorations clinically at each appointment. There were no significant differences in VAS scores between the two groups at any appointment period (two-way ANOVA; p > 0.05). Several conditions were defined as indicating marginal stress before the start of the trial. At 24 months, there was no significant difference between the SS and PAC groups. Within the limitations of this study, Class I and II restorations placed with a SS technique did not show significant changes in post-op sensitivity or decreased signs of marginal stress.

Research paper thumbnail of Postoperative Sensitivity: A Comparison of Two Bonding Agents

Operative Dentistry, 2007

Historically, postoperative pain associated with temperature was considered a thermal conduction ... more Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent. This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared. For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American Journal of Dentistry, Feb 1, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity recorded. The difference in sensitivity between the two products proved to be statistically significant (Chi-square analysis, P < or = 0.0001). The median shade change for both products following 2 weeks of active treatment was six tabs. At the 4-week evaluation, the median shade change was 5.5 and 6.0 tabs respectively for Rembrandt and Nite White. There was no statistical difference between the products in respect to shade change.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...

Research paper thumbnail of Effect of Restoration Size on the Clinical Performance of Posterior “Packable” Resin Composites Over 18 Months

Operative Dentistry, 2007

Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restor... more Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restorations were placed in molars under rubber dam isolation. The restorative systems used were: Alert Condensable (Jeneric/Pentron) and SureFil (Dentsply/Caulk). The restorations were classified according to size, with 7 small, 25 moderate and 18 large, of which 8 were cusp replacement restorations. Baseline, 6, 12 and 18-month double-blinded clinical evaluations were carried out using modified USPHS criteria. The independent variables: restorative material, restoration size and three other clinical factors, were tested using a Multiple Logistic Regression procedure to determine if any were predictive of failure. Of the 50 restorations, four failed by the 18-month recall, three failed due to fracture of the restoration and one due to secondary caries. Both restorative systems demonstrated a 92% success rate. No association between restoration size (p = 0.99) or restorative material (p = 0.65) and failure was found. Similarly, the additional variables, occlusal contact type, presence of occlusal wear facets and first or second molar, were not predictive of failure.

Research paper thumbnail of A Comparison of Human Raters and an Intra-oral Spectrophotometer

Operative Dentistry, 2009

Consistently choosing an accurate shade match is far more difficult than it appears. Recently, se... more Consistently choosing an accurate shade match is far more difficult than it appears. Recently, several electronic shade-matching devices have been marketed. One device is an intraoral spectrophotometer, Easyshade. The current study compared the accuracy and consistency of the Easyshade (ES) device to three clinicians experienced in tooth whitening trials and trained in the use of the Vitapan 3D Master shade. The maxillary anteriors of 16 participants were matched on three separate occasions one month apart. At each appointment, the three clinicians (R1, R2 & R3) and ES independently chose a single 3D Master tab. A trained research assistant used the Easyshade device to record CIE L*, C* and H* and a shade tab. In addition, color differences between shade tabs were calculated using the Delta E 2000 (delta e 00) formula. The CIE L*C*H* data were also used to establish standards for the five lightness groups of the 3D Master. An intrarater agreement was evaluated using an intraclass correlation statistic, and an inter-rater agreement was evaluated using a weighted Kappa statistic. The percentages of exact matches were: ES = 41%; R1 = 27%; R2 = 22% and R3 = 17%. Matches within a half-shade were also calculated. This represents a mismatch that is perceptible but acceptable. The percentages of matches within a half-tab were: ES = 91%; R1 = 69%; R2 = 85% and R3 = 79%. In terms of lightness, the intra-rater agreement was considered to be very good for ES and R2 and good for R1 and R3. For chroma, agreement for ES was considered good, and for the three clinicians, it was considered moderate. The mean color difference for the L*, C*, H* data recorded at each evaluation was 1.5, or only slightly greater than the color difference between the same tab on different guides (1.2). The delta e 00 data were the most accurate data collected, and they were used to establish a standard to which the tab choices of the four raters were compared. A weighted Kappa statistic was performed and, in terms of lightness, agreement was found to be good for all raters. For chroma, agreement was very good for ES and it was good for the clinicians. In terms of the number of exact matches and matches within a half-shade, the performance of ES was at least comparable to, if not better than, the dentists. Statistically, the same was true in terms of consistency and accuracy when making repeated matches of lightness and chroma using the 3D Master shade guide.

Research paper thumbnail of Comparison of Traditional and Low Sensitivity Whiteners

Operative Dentistry, 2008

This placebo-controlled, double-blind randomized clinical trial compared five 10% carbamide perox... more This placebo-controlled, double-blind randomized clinical trial compared five 10% carbamide peroxide tooth whitening formulations. Three products contained varying concentrations of potassium nitrate as desensitizers. One contained no desensitizers and one was a placebo. During the two weeks of active bleaching, participants used a daily diary to record the number of days of sensitivity from hot, cold, gums, tongue and/or throat. The total number of days of sensitivity experienced by the participants in each group was compared. Participants using the agent with no desensitizers did not experience any more sensitivity than those using the agent containing 3% potassium nitrate. The products that included 0.5% potassium nitrate and 0.5% potassium nitrate and 0.25% sodium fluoride were not associated with any more sensitivity than the placebo group. In addition, the shade tab change from baseline to 11 weeks following cessation of bleaching was compared. Using an active bleaching agent, no difference in color change was noted among the four groups. All four groups were associated with significantly higher color change than the placebo. The addition of a small percentage of potassium nitrate to a 10% carbamide peroxide tooth whitener was shown to significantly reduce postoperative sensitivity without reducing efficacy.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...

Research paper thumbnail of The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

Operative Dentistry, 2007

This study evaluated the amount of residual yellow in cured resin composites when polymerizing wi... more This study evaluated the amount of residual yellow in cured resin composites when polymerizing with either a quartz-tungsten-halogen (QTH) or blue light-emitting diode (LED). Twelve shades (bleaching to conventional shades) of microfill, hybrid and microhybrid resin composite specimens (n = 10) were polymerized with both light types. All the materials contained only camphorquinone as the photoinitiator. After exposure, the specimens were stored in the dark for 24 hours. Then, the specimen color parameters were recorded (L*, a*, b* and C*(ab)) and color differences (deltaE*(ab)) were determined by examining for changes among the test combinations. Group comparisons were examined using ANOVA and the Tukey-Kramer post-hoc test, and pairwise comparisons were made using the Student's t-tests at a pre-set alpha of 0.05. When a significant difference in the shade of yellow was noted, the QTH light produced a greater yellow tinge than most comparisons using the LED. The potential for producing more residual yellowing could not be anticipated with respect to composite filler classification or shade, as this effect may be more dependent on individual product composition. The extent to which residual yellowing differences were noted between light curing units fell within levels considered detectable by the human eye (deltaE > 2.0). The selection of light curing unit to polymerize resin-based restorative materials can have a significant influence on the amount of residual yellow present, with the QTH light tending to leave more yellow than an LED unit.

Research paper thumbnail of Postoperative Sensitivity: A Comparison of Two Bonding Agents

Operative Dentistry, 2007

Historically, postoperative pain associated with temperature was considered a thermal conduction ... more Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent. This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared. For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

Research paper thumbnail of Color differences: Polymerized composite and corresponding Vitapan Classical shade tab

Journal of Dentistry, 2009

This study compared newer composite resin restorative materials to the Vitapan Classical tabs the... more This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

Research paper thumbnail of Class II restoration combining a low-shrinkage composite and a centripetal technique

Research paper thumbnail of Penetration of fluids into periodontal pockets using a powered toothbrush/irrigator device

The Journal of Contemporary Dental Practice, Jan 7, 2006

This study was a single-blind, randomized, controlled clinical trial. The researchers evaluated a... more This study was a single-blind, randomized, controlled clinical trial. The researchers evaluated a powered brush/irrigating device (HydraBrush Oral Health System; OHS) for its safety and ability to deliver a solution to the bottom of 5-6 mm pockets, compared to rinsing alone with a solution following brushing with a powered toothbrush (Sonicare Elite 7800; SE). An evaluation technique to measure the quantity and quality of solution able to enter the pocket was also introduced in this project.METHODS: Subjects were randomized in one of two-groups: brush plus simultaneous irrigation (OHS) versus brush plus rinsing (SE). Subjects used their devices at home for two weeks. At the measurement visit, subjects used the OHS to irrigate and brush simultaneously for 1 minute (30 seconds per each side of the mouth) with a 0.01% erythrosine disclosing solution in 10 oz of distilled water. Control subjects brushed for 2 minutes with a SE followed by a 1 minute rinse with an identical disclosing solution. A blinded evaluator collected six samples of approximately of 1 microL of sucular fluid from six 5-6 mm evaluation sites. This was accomplished by inserting a microcapillary tip with a 20 microL micropipette in the sulcus. Two-group repeated measures ANOVA was used to examine differences in two measures of the disclosing solution between OHS and SE subjects; the spectrometer reading of the disclosing solutions, and by visual inspection of the samples (positive/negative) to determine the presence or absence of solution in the samples. Subjects' diaries were collected. Bleeding and discomfort during the evaluation period was reported.RESULTS: Visually, OHS had a significantly greater proportion of solution taken from the base of 5-6 mm sites than the SE (p=0.0001). However, there was no statistical difference between the two groups (p=.1359) in the spectrophotometer readings.CONCLUSION: The experimental device is more efficient in delivering a solution to the base of 5-6 mm pockets than rinsing following use of a control powered toothbrush. Both devices have demonstrated they are safe and well accepted by patients. The technique developed provides a useful method for quantitative and qualitative studies of solutions from the base of periodontal pockets.

Research paper thumbnail of Comparison of two low sensitivity whiteners

American Journal of Dentistry, Feb 1, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity recorded. The difference in sensitivity between the two products proved to be statistically significant (Chi-square analysis, P < or = 0.0001). The median shade change for both products following 2 weeks of active treatment was six tabs. At the 4-week evaluation, the median shade change was 5.5 and 6.0 tabs respectively for Rembrandt and Nite White. There was no statistical difference between the products in respect to shade change.

Research paper thumbnail of Two-year clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material

Operative Dentistry

This study compared the clinical performance of a polyacid-modified resin composite and a resin-m... more This study compared the clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material over two years. Thirty-four pairs of restorations of Compoglass and Fuji II LC were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. A significantly higher incidence of failed restorations was found with the polyacid-modified resin composite (p < 0.05).

Research paper thumbnail of Two-year clinical performance of Class V resin-modified glass-ionomer and resin composite restorations

Operative Dentistry

While a one-year report had been previously published, this study was undertaken to evaluate the ... more While a one-year report had been previously published, this study was undertaken to evaluate the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over two years. Thirty-seven pairs of restorations of FujI II LC and Z 250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. No statistically significant difference (p = 0.13) was observed in the overall performance of the materials. Retention was 96% for the resin-modified glass ionomer and 81% for the resin composite, with no additional restorations of either material lost after one year. As previously reported, retention of the Z 250 restorations at six months was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. The resin composite restorations generally had a better appearance, with a 100% alpha rating in color match, versus 85% for the resin-modified glass ionomer.

Research paper thumbnail of One-year clinical performance of a resin-modified glass ionomer and a resin composite restorative material in unprepared Class V restorations

Operative Dentistry

This study evaluated the clinical performance and appearance of a resin-modified glass ionomer an... more This study evaluated the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over one year. Thirty-seven pairs of restorations of Fuji II LC and Z250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline and 6 and 12 months, using modified Ryge/USPHS criteria. No significant difference (p>0.05) was observed in performance of both materials, although retention of the Z250 restorations was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. Little difference in the restorations' appearance was observed.

Research paper thumbnail of 8-week Cytotoxicity of Contemporary Endodontic Sealers In Vitro

Objectives: Contemporary endodontic sealers are distinct from traditional sealers used with gutta... more Objectives: Contemporary endodontic sealers are distinct from traditional sealers used with gutta percha for canal obturation. The long-term biocompatibility of these sealers is critical to peri-apical healing, but has not been adequately defined. We assessed responses of fibroblasts and osteoblasts to contemporary sealers that were aged' for up to 8 wk. Methods: AH-plus Jet (AH), two versions of Endo Rez (Rez, ExRez), Epiphany (Eph), and traditional Pulp Canal Sealer (PCS) were mixed according to manufacturers' directions and formed into discs (n = 6). MC3T3 mouse osteoblasts, ROS 17/2.8 rat osteoblasts, and L929 mouse fibroblasts were exposed to the sealers for 72 h initially or after the specimens had been placed in phosphate-buffered saline for 4 or 8 wk. Cellular response was assessed using mitochondrial succinate dehydrogenase (SDH) activity (MTT method) by normalizing to Teflon control materials. The cellular responses to the materials were compared using ANOVA with T...

Research paper thumbnail of Eighteen-month clinical performance of a self-etching primer in unprepared class V resin restorations

Operative Dentistry

This study evaluated the clinical performance of unprepared Class V resin composites, placed usin... more This study evaluated the clinical performance of unprepared Class V resin composites, placed using a self-etching primer and a single-bottle adhesive, over a period of 18 months. Thirty-eight pairs of restorations of Renew hybrid resin composite (BISCO, Inc) were placed using adhesives from the same manufacturer in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 76% of these lesions was considered to be sclerotic. The restorations were placed without abrasion of tooth surfaces, except for cleaning with plain pumice. One of each pair was placed using Tyrian, a self-etching primer and the other was placed using One-Step, a single-bottle adhesive placed after acid etching. Both the etchant and self-etching primer were applied for 20 seconds. The restorations were clinically evaluated at baseline, 6, 12 and 18 months, using modified Ryge/USPHS criteria. For both adhesives, very low retention of 50% to 56% of the restorations was observed ove...

Research paper thumbnail of Comparison of two low sensitivity whiteners

American journal of dentistry, 2008

To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for th... more To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity re...