DR. SAAD MISFER AL-SHAHRANI*, DR. DINA AL-SUDANI**
*King Fahad Military Medical Complex,
** College of Dentistry, King Saud University, Riyadh, Saudi Arabia

The purpose of this investigation was two-fold, first; to compare the ability of three NiTi rotary systems (ProFile, K3, and RaCe) to centralize instrumentation relative to the original canal location, second; to determine the direction and lengths of transportation of these canals. Sixty mesial root canals of thirty mandibular first and second molars with curvature ranging from ^o to ⁴0o were selected. The canals were divided randomly into three groups of 20 canals each. The roots were sectioned horizontally at 3mm, 5mm, and 8mm from the root apex. Teeth were reassembled and instrumented using manufacturer's recommendation, all groups prepared to size 30 (0.06) taper master apical file. The cross sections were digitally scanned before and after preparation and the images were analyzed by image analysis software for the centering ability and extent and the direction of transportation. The three groups were statistically compared by Analysis of Variance ANOVA and Chi-square test. The results indicated that all rotary NiTi systems used in this study were able to preserve dentin structure. ProFile system significantly caused less canal transportation; remained well centered in the canal. RaCe system significantly showed the maximum extent of transportation. It was concluded that ProFile system was found to be the best for all variables measured in this study followed by K3, and RaCe. This difference in outcomes may be due to differences in cross sectional design of the three NiTi systems.
Saudi Dental Journal 2006;18(SI)-Abstr.061

062.Efficacy of two rotary NiTi instruments in the removal of gutta-percha during root canal treatment

DR. NASSER AL-KATHEERI
King Fahad Medical City,Riyadh, Saudi Arabia

The aim of this study was to evaluate the efficacy of two rotary MTi instruments, ProTaper and K3, in the removal or gutta-percha during root canal retreatment in comparison with hand instruments using Hedstrom files. Retreatment time and amount of apically extruded debris were also recorded and evaluated.

Sixty extracted single-rooted anterior teeth and premolars were instrumented to size # 40 and obturated with laterally condensed gutta-percha using AH-26 sealer cement. The teeth were randomly divided into three groups, 20 teeth each. Removal of gutta-percha was performed with chloroform and one of the following techniques: (1) Hedstrom files, (2) ProTaper, and (3) K3. The roots were split longitudinally and digitized using scanner. The area of the whole canal, the area of each third, and the area of remaining filling materials in the whole canal and in each third were traced using Ulead PhotoImpact 7 then calculated using Sigma Scan software. The remaining filling materials were expressed in percentage.

The results indicated that the two rotary NiTi instruments left significantly less remaining materials (P <0.0001) compared to Hedstrom files while there was no significant difference between the two rotary instruments. In all groups, the apical thirds showed the highest ratio of remaining materials compared to middle and coronal thirds. The retreatment time was significantly less (P < 0.0001) when the two rotary NiTi instruments were used compared to hand. There was no statistically significant difference (P = 0.159) found between the three techniques regarding the amount of apically extruded debris.

In conclusion, the two rotary NiTi instruments, ProTaper and K3 were found to be effective and faster in removing gutta-percha.
Saudi Dental Journal 2006;18(SI)-Abstr.062

063.Tobacco smoking and vertical periodontal bone loss

DR. MOSTAFA BALJOON*, DR. SUSAN NATTO*
DR. ABDULHADI ABANMY*

*Al-Noor Hospital, Makkah, Saudi Arabia,
**Department of Dentistry, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia

Purpose: To investigate the relationship between water pipe and cigarette smoking and the prevalence and severity of vertical periodontal bone defects.

Material and Methods: A study sample of 355 individuals in the age range 17 to 60 years was recruited from Jeddah, Saudi Arabia. Full sets of intra-oral radiographs for each individual were assessed with regard to the presence or absence of vertical bone defects. A vertical defect was defined as an angular resorption of the interdental marginal bone of 2 mm or more at either the mesial or distal aspect of the root.

Results: The overall prevalence of vertical defects was 39%, with a specific prevalence of 47% in water pipe smokers, 54% in cigarette smokers, and 23% in non-smokers. The prevalence was significantly elevated in both types of smokers compared with non-smokers (P < 0.001). Expressed as the proportion of sites with vertical defects per person, the severity was 2.6% for water pipe smokers, 2.8% for cigarette smokers, and 1.3% for non-smokers. The association between smoking and severity of vertical defects was statistically significant (P < 0.001). The severity of vertical defects was significantly greater in heavy exposure compared to light exposure smokers in water pipe as well as cigarette smokers (P < 0.001). The relative risk associated with water pipe and cigarette smoking was 2.9-fold and 6.6-fold increased, respectively, compared to non-smoking.

Conclusion: The present observations suggest that prevalence and severity of vertical periodontal bone defects are increased in tobacco smokers. The association of vertical bone loss with water pipe smoking is comparable to the association with cigarette smoking.
Saudi Dental Journal 2006;18(SI)-Abstr.063

DR. MESHARI FARAJ AL-OTAIBI, DR. M. AL-HARTHY, DR. A. GUSTAFSSON, DR. A. JOHANSSON, DR. R. CLAESSON,DR. R.ANGMAR, DR. B. MANSSON
  Dental Department, Security Forces Medical Center, Makkah, Saudi Arabia

Background: The chewing stick, the miswak, is used in many developing countries as the traditional means for oral hygiene. It is prepared from the roots, twigs and stem of Salvadora persica or other alternative local plants. The objective is to compare the effects of the chewing stick miswak (from S. persica) and toothbrush on subgingival plaque microflora among Saudi Arabian individuals. Further, to investigate whether components extracted from S. persica may interfere with the subgingival plaque micro­organisms.

Material and Methods: Fifteen healthy Saudi Arabian male volunteers aged 21-36 years were included in a single-blind, randomized cross-over study. The participants were taught how to use each device properly. Plaque sampling for DNA test was performed at the baseline, 1 week after professional tooth cleaning, and after 3 weeks of either miswak or toothbrush use. Identification and quantification of microbial species were performed by the checkerboard method, using whole genomic, digoxigenin-labelled DNA probes. Inhibition zones around miswak were examined on agar plates with Actinobacillus actinomycetemcomitans and the leukotoxicity of this bacterium was analyzed in a bioassay with macrophages +/- extracts of miswak.

Results: Miswak and toothbrushing had a similar influence on the levels of the subgingival microbiota. However, A. actinomycetemcomitans was significantly more reduced by miswak (P < 0.05) than by toothbrushing. These results were supported by our in vitro results which, indicated that extracts from S. persica might interfere with the growth and leukotoxicity of A. actinomycetemcomitans.

Conclusion: In contrast to toothbrush use, miswak use significantly reduced the amount of A. actinomycetemcomitans in the subgingival plaque.
Saudi Dental Journal 2006;18(SI)-Abstr.064

DR. MOHAMMED AL-RASHEED
King Fahad Medical City, Riyadh, Saudi Arabia

 
In this study the accuracy of one-step, two-step putty wash and the monophasic single-mix addition silicone impression techniques was evaluated by comparing the dimensions of the poured dies to the standard stainless steel model (Control). Furthermore, the stability of each technique was determined by comparing the dimensions of delayed poured dies to a standard stainless steel model (Control).

A stainless steel model containing two full-crown abutment preparations was used as the positive control. Thirty replications for each of the mentioned techniques were made. In each technique, ten impressions were poured after 1 hour, 1 day, and 1 week. Accuracy and stability of the poured dies were assessed by measuring three dimensions of the stone dies namely: Inter-die, die width, and die height distances using traveling microscope and these dimensions were compared to that of the stainless steel model.

Data were statistically analyzed using two-way analysis of variance to compare the means of percentage changes. Tukey post-hoc test was employed to determine the significant group. The results indicated that there were no statistically significant differences in the accuracy of all the three dimensions among the three impression techniques. Furthermore, the impressions poured from two-step putty wash and monophasic single-mix impression techniques at 1 hour differed significantly (P<0.0001) in (I.D) distance compared with 1 week delayed pour. However, the differences in this distance measurement.
Saudi Dental Journal 2006;18(SI)-Abstr.065