Dentistry, College of

Clinical Assessment of Primary Implant Stability Parameters Using a Stereolithographic Surgical Guide

Thu, 21 Feb 2013 06:00:00 GMT

Clinical Assessment of Primary Implant Stability Parameters Using a Stereolithographic Surgical Guide Purpose: The objective of this investigation was to determine if there was a correlation between the circumferential mean bone density calculated quantified using computed tomography (CT), maximum applied insertion torque value, and the implant stability quotient (ISQ). Materials and Methods: Medical grade CT was utilized in conjunction with rapid prototyping to fabricate a stereolithographic (SLA) surgical guide. Nineteen self-tapping dental implants (OsseospeedTX ™) with a length ≥ 11mm were placed in eight patients using a SLA surgical guide, either tooth-mucosa supported or bone-supported. The circumferential mean bone density was quantified pre-operatively using CT in Hounsfield (HU) units using Facilitate™ computer-guided implant software. The maximum applied insertion torque value was recorded using the W&H ImplantMed™. Primary stability was quantified in ISQ values with the wireless Ostell™Mentor instrument using resonance frequency analysis (RFA) at the time of dental implant placement. Three measurements were taken from the buccal and lingual for a total of six measurements for each dental implant using RFA. The Pearson correlation coefficient was implemented to determine the presence of positive correlations between the parameters of circumferential mean bone density calculated using CT; the mean bone densities calculated using CT at the coronal, midcrestal, apical regions; maximum applied insertion torque value, and the implant stability quotient (ISQ). The linear regressions for the Pearson correlation coefficient were converted to p-values using biostatistics software (Systat™ software 13;Systat Software, Inc., Chicago, IL). A positive correlation amongst the parameters was reported when p-value < 0.05. Results: There was a positive correlation found between the circumferential mean bone density and the maximum applied insertion torque values for all implants (r = 0.862, p < 0.001). No correlation was found between circumferential mean bone densities and the mean ISQ values (r = 0.275, p > 0.05). No correlation was found between the measurements of mean ISQ values and the maximum applied insertion torque values (r = 0.056, p > 0.05). Conclusion: A mean maximum applied insertion torque value of 33.2 Ncm for all dental implants was correlated with the circumferential mean bone densities calculated using CT pre-operatively. Since no correlation was found between circumferential mean bone density and the mean ISQ vales or between maximum applied insertion torque and the ISQ. It seems rationale to conclude that the high mean ISQ value of 72 ± 2.80 for all dental implants was a result of the surgical approach implemented using computer-guided implant software to maximize the length of a potential implant site to ≥ 11mm.

Effect Of Bioactive Irrigants On Intraradicular Dentin Microstructure During Endodontic Therapy

Thu, 21 Feb 2013 06:00:00 GMT

Effect Of Bioactive Irrigants On Intraradicular Dentin Microstructure During Endodontic Therapy Irrigation using sodium hypochlorite is the most recommended irrigating solution in endodontics for the removal of remnants and dentine debris during instrumentation, however, it may cause changes to the organic and mechanical properties of dentine. Previous studies have shown that modification to the collagen by altering the number of cross-links, enhance the mechanical properties and lower rates of enzymatic degradation. Plant derived natural products represent a rich source of antimicrobial compounds. Grape seed extract (GSE), mainly composed of Proanthocyanidin and Tannic acid which is a chemical derived from certain plants, such as oak wood, have demonstrated the ability to create inter- and intra-molecular collagen cross-links in biological tissue. These cross-links affect the mechanical properties of demineralized dentin by increasing the level of stiffness, as measured by the Flexural Strength, and provide resistance against enzymatic degradation. We hypothesize that the use of crosslinking agents tannic acid (TA) and grape seed extract (GSE) will not have a significant effect on the flexural strength and dentin collagen biodegradation of intraradicular dentin. Extracted single-rooted permanent teeth were sectioned into 7x3x0.3 mm3 beams and randomly assigned to four groups according to the irrigation type : Group 1: Saline, Group 2: EDTA 17%, 5.25%NaOCl; Group 3:5.25% NaOCl, 20% TA , Group 4: 5.25% NaOCl, 30% GSE. Specimens were tested for flexural strength (MPa), dentin collagen biodegradation using bacterial collagenase for 24 hours, and calculating the amount of digested matrix, and denaturation temperature of dentin matrix. Statistical analysis was performed using one-way ANOVA test (α=0.05). To assess flexural strength, specimens were loaded to fracture at a crosshead speed of 1mm/min. Data analysis was performed by one-way ANOVA test (α= 0.05), and revealed no statistically significant differences in flexural strength among groups , although high values were observed for TA in comparison to EDTA>NaOCl , GSE, and Saline groups. TA was borderline significance in reducing the collagen degradability when compared to the other irrigants. Therefore, we concluded that the use of saline, NaOCl, TA and GSE didn’t affected the flexural strength, rate of collagen biodegradation and collagen thermal transition of root dentin, and the null hypothesis was accepted.

In vitro Effects of Berberine versus Sodium Hypochlorite on Dentin Flexural Strength

Thu, 13 Dec 2012 06:00:00 GMT

In vitro Effects of Berberine versus Sodium Hypochlorite on Dentin Flexural Strength Berberine, a goldenseal extract, has been proven to effectively reduce the bacterial load of E. faecalis in a tooth model. Objective: To measure the root dentin strength, by evaluating flexural strength, collagen degradation, and collagen temperature denaturation after exposure to irrigating solutions of Berberine Chloride (BBr), Sodium hypochlorite (NaOCl), or a BBr/NaOCl combination. Methods: Twenty-four caries, restoration and crack-free single-rooted human permanent teeth were decoronated and the apical 1/3 of each root was sectioned to prepare 7.0mm root samples. Dentin beams (sections) were prepared by making 7mmX3mmX0.3mm slices through each root. Control beams for each group were prepared from the same tooth as the experimental group. Irrigation was performed on one surface of the tooth samples. Teeth were divided into four groups as follows: Group 1-60 seconds irrigation with saline; Group 2- 60 seconds irrigation with 0.2% BBr; Group 3- 120 seconds irrigation with 5.25% NaOCl; Group 4- 120 seconds irrigation 5.25% NaOCl followed by 60 seconds irrigation 0.2% BBr. Specimens were then tested for flexural strength using a 3-point flexural device. From the same teeth, dentin disks were cut into 2mmX2mmX0.25mm to measure collagen degradation using a collagen digestibility method and collagen temperature denaturation was examined by a differential scanning calorimeter (DSC). Statistical analysis was performed using one-way ANOVA (p<0.05). Results: No statistically significant differences in flexural strength, collagen degradation, and collagen temperature denaturation among groups (p>0.05) was detected. Conclusion: Irrigation with berberine and/or sodium hypochlorite did not alter radicular dentin strength when compared to saline.

Impact of Childhood Obesity on Oral Health

Thu, 13 Dec 2012 06:00:00 GMT

Impact of Childhood Obesity on Oral Health Childhood obesity is reaching epidemic proportions in the United States and worldwide. Both obesity and poor oral health may increase a person’s risk for systemic disease and poor dietary habits may be one of the factors linking both multifactorial conditions together. Studies have investigated the association between obesity and dental caries, the results have been contradictory. This cross-sectional pilot study in children aged 8-12 tests the hypothesis that obese children have poorer oral health compared to healthy-weight children. To measure oral health, decayed and filled teeth (dft+DFT) scores, gingival index and plaque index was examined in 20 obese and 20 healthy-weight children. It represents part of a larger cross-sectional study that compared the oral health conditions, salivary characteristics, and dietary habits between obese and healthy weight 8-12 years old children. The results of the oral examination found no differences in caries experience, plaque or gingival scores between the two groups. However, BMI was inversely correlated with caries experience. Among the children recruited outside of the UIC dental school, the obese children had significantly lower caries experience. The larger study examining the dietary habits and properties of saliva could find additional differences between the groups and offer some insights as to why this inverse relationship may exist.