Heat Generation on Implant Surface During Abutment Preparation at Different Elapsed Time Intervals.

PURPOSE: The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. MATERIALS AND METHODS: Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each). Group 1: the temperature was maintained at 20 ± 1°C; and group 2: the temperature was maintained at 32 ± 1°C. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute. The temperature of the heat generated from abutment preparation was recorded and measured at 3 distinct time intervals. RESULTS: Water-coolant temperature (20°C vs 32°C) had a statistically significant effect on the implant's temperature change during preparation of the abutment (P < 0.0001). CONCLUSION: The use of water-coolant temperature of 20 ± 1°C during preparation of the implant abutment decreased the temperature recorded at the implant surface to 34.46°C, whereas the coolant temperature of 32 ± 1°C increased the implant surface temperature to 40.94°C.

Pull-out retentive strength of fiber posts cemented at different times in canals obturated with a eugenol-based sealer.

STATEMENT OF PROBLEM: Currently, no standard luting protocol exists for fiber posts. In addition, no agreement has been reached on the time interval between canal obturation and post space preparation and cementation. PURPOSE: The purpose of this in vitro study was to evaluate the retention of fiber posts cemented with 3 different types of cement: Paracore, Variolink II, and RelyX Unicem cement after 24 hours or 2 weeks in root canals obturated with gutta percha and a eugenol-based sealer. MATERIAL AND METHODS: Seventy-two caries-free, freshly extracted, single-rooted human mandibular first premolar teeth with straight root canals were prepared and obturated with gutta percha and Endofil sealer. Specimens were divided into 2 groups (n=36): post spaces prepared 24 hours after obturation and post spaces prepared 2 weeks after obturation. Posts in both groups were luted with 1 of 3 different luting agents (n=12), ParaCore, Variolink II, or RelyX Unicem cement. Each tooth specimen was vertically secured in a universal testing machine, and a constant pull-out loading rate of 0.5 mm/min was applied until cement failure occurred. Data were statistically analyzed with 2-way and 1-way ANOVAs and t tests. RESULTS: Two-way ANOVA indicated statistically significant differences in mean post retention among the 3 cement types (P<.001) and among the means of the different time intervals investigated (P<.001). Significant differences were noted among all cement types tested between the 24-hour and 2-week time intervals (P<.05). CONCLUSIONS: Time elapsed between canal obturation and post cementation significantly influenced fiber post retention, regardless of the type of resin cement. Fiber posts showed significantly higher retention if cemented after 24 hours of obturation than if cementation occurred after 2 weeks.

Effect of endodontic sealers on push-out bond strength of cemented fiber posts.

OBJECTIVE: The purpose of this study was to compare the effect of eugenol-based and resin-based endodontic sealers on the push-out bond strengths of prefabricated fiber posts luted with different resin cements. METHOD AND MATERIALS: Ninety prefabricated fiber posts were luted into extracted singlerooted teeth with one of three resin cements (Variolink II, ParaCore, or Rely X Unicem). Each group was subdivided into three groups with 10 teeth each. The first two groups were obturated with gutta percha and one of two eugenol-based endodontic sealers (Endofil or TubliSeal) each. The third group was obturated with gutta percha and (AH26) resin-based root canal sealer. Push-out tests were performed in a universal testing machine by applying a load speed at 0.5 mm/min by using a 1-mm-diameter metallic plunger which induced a load in an apical to coronal direction. The maximum value for post dislodgement (in Newtons) was recorded. Data were collected and statistically analyzed using two-way ANOVA and Tukey multiple comparison tests (α = .05). RESULTS: The highest mean bond strength values were recorded for the AH26 sealer group (non-eugenol sealer) luted with Rely X Unicem resin cement (mean ± SD = 326.1 ± 66.1 N), while the lowest mean bond strength values were observed with posts luted with Variolink II resin cement into canals obturated with gutta-percha and Endofil (eugenol-based) sealer (90.3 ± 25.2 N). There was no significant difference between the means of push-out strengths for the Endofil and TubliSeal groups (P = .745). CONCLUSION: Eugenol-based sealers (Endofil and TubliSeal) significantly reduced the push-out bond strength of prefabricated fiber posts luted with resin cement.

Implant Fixture Heat Transfer During Abutment Preparation.

The purpose of the study was to evaluate the effect of water flow rate on the heat transmission in implants during abutment preparation using a diamond bur in a high-speed dental turbine. Titanium-alloy abutments (n = 32) were connected to a titanium-alloy implant embedded in an acrylic resin within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each) according to the water flow rate used during the preparation phase. Group 1 had a water flow rate of 24 mL/min, and group 2 had a water flow rate of 40 mL/min. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute with a coarse tapered diamond bur using a high-speed dental handpiece. Thermocouples embedded at the cervix of the implant surface were used to record the temperature of heat transmission from the abutment preparation. Heat generation was measured at 3 distinct times (immediately and 30 seconds and 60 seconds after the end of preparation). Statistical analyses were carried out using 2-way analysis of variance and the Student t test. Water flow rates (24 mL vs 40 mL) and time interval had no statistically significant effect on the implant's temperature change during the abutment preparation stage (P = .431 and P = .064, respectively). Increasing the water flow rate from 24 to 40 mL/min had no influence on the temperature of the implant fixture recorded during preparation of the abutment.

Standards of teeth preparations for anterior resin bonded all-ceramic crowns in private dental practice in Jordan

OBJECTIVES: To investigate if general dental practitioners (GDPs) in private practice in Jordan follow universal guidelines for preparation of anterior teeth for resin bonded all-ceramic crowns (RBCs). MATERIAL AND METHODS: A sample (n=100) of laboratory models containing 208 tooth preparations for IPS Empress and In Ceram, featuring work from different GDPs, was obtained from 8 commercial dental laboratories. Aspects of preparations were quantified and compared with accepted criteria defined following a review of the literature and recommendations of the manufactures' guidelines. RESULTS: Subgingival margins on the buccal aspect were noticed in 36 percent of the preparations, 54 percent demonstrated overpreparation with a tendency to overprepare the teeth on the mesiodistal plane more than buccolingual plane. Twenty percent of samples presented a shoulder finish line while a chamfer margin design was noticed in 39 percent. Twenty-nine percent and 12 percent of samples had either a feathered or no clear margin design respectively. Incisal underpreparation was observed in 18 percent of dies of each type. Only 17 percent of all preparations were found to follow the recommended anatomical labial preparations while 29 percent of the RBC preparations were found to have the recommended axial convergence angle. In total, 43 percent of preparations were found to have the recommended depth of the finish line. CONCLUSIONS: It was found that relevant guidelines for RBC preparations were not being fully adhered to in private practice in Jordan.

Standards of teeth preparations for anterior resin bonded all-ceramic crowns in private dental practice in Jordan.

OBJECTIVES: To investigate if general dental practitioners (GDPs) in private practice in Jordan follow universal guidelines for preparation of anterior teeth for resin bonded all-ceramic crowns (RBCs). MATERIAL AND METHODS: A sample (n=100) of laboratory models containing 208 tooth preparations for IPS Empress and In Ceram, featuring work from different GDPs, was obtained from 8 commercial dental laboratories. Aspects of preparations were quantified and compared with accepted criteria defined following a review of the literature and recommendations of the manufactures' guidelines. RESULTS: Subgingival margins on the buccal aspect were noticed in 36% of the preparations, 54% demonstrated overpreparation with a tendency to overprepare the teeth on the mesiodistal plane more than buccolingual plane. Twenty percent of samples presented a shoulder finish line while a chamfer margin design was noticed in 39%. Twenty-nine percent and 12% of samples had either a feathered or no clear margin design respectively. Incisal underpreparation was observed in 18% of dies of each type. Only 17% of all preparations were found to follow the recommended anatomical labial preparations while 29% of the RBC preparations were found to have the recommended axial convergence angle. In total, 43% of preparations were found to have the recommended depth of the finish line. CONCLUSIONS: It was found that relevant guidelines for RBC preparations were not being fully adhered to in private practice in Jordan.

The relationship between tobacco smoking and oral colonization with Candida species.

AIM: The aim of this study was to assess and compare the quantitative and qualitative oral colonization of Candida species between a group of healthy tobacco smokers and a comparable group of nonsmokers, and to investigate a possible correlation between oral candidal colonization and the quantity or duration of the smoking habit. METHODS AND MATERIALS: Fifty smokers and 50 nonsmokers were included in the study. Candida species were isolated using the concentrated oral rinse (COR) technique and identified using the germ tube test and API 20 C AUX yeast identification system. RESULTS: Overall candidal transmission was 84 percent. Candida species were isolated from 42 (84 percent) of the smokers and 37 (74 percent) of the nonsmokers (p>0.05). The mean CFU/ml were 333 (SD=358) and 268 (SD=332), respectively (p>0.05). CONCLUSION: Tobacco smoking did not appear to increase oral colonization with Candida species in healthy subjects. CLINICAL SIGNIFICANCE: The effects of smoking on oral tissues and the mechanisms by which Candida proliferate intra-orally as a result of cigarette smoking warrant additional study.

Prevalence and risk factors associated with denture-related stomatitis in healthy subjects attending a dental teaching hospital in North Jordan.

UNLABELLED: There is scant information regarding the prevalence of denture-related stomatitis (DRS) in Jordan. AIMS: The aims of this study were to investigate the prevalence of DRS in a group of healthy Jordanian subjects wearing removable complete dentures, and to investigate for the factors that may be associated with this infection. MATERIALS AND METHODS: A total of 300 complete denture patients attending a dental teaching centre in North Jordan for replacement dentures were examined thoroughly for the presence of DRS. Demographic data, including denture-wearing habits, duration of denture usage and smoking, were also obtained. Oral mucosal tissues were examined for signs of denture trauma. Dentures were assessed for plaque accumulation. RESULTS: Of the 300 subjects examined, 175 were male and 125 were female. The overall prevalence of DRS in males and females was 52% (157/300). Increased plaque deposits (plaque indices 2 and 3) were significantly more prevalent in subjects with severe forms of DRS (p<0.01). Dentures that were more than 20 years old were located in the group of subjects with grade 2 and 3 infections. A total of 86% of patients with DRS complained of denture trauma compared to 10% of subjects with healthy mucosa, and 87% of the DRS group wore dentures continuously day and night. A total of 70% of subjects with grade 3 DRS were heavy smokers (more than 15 cigarettes/day). CONCLUSION: Local factors studied contributed significantly to the development of DRS in healthy subjects and are important factors to be considered in the pathogenesis of this infection.

Infection control procedures in commercial dental laboratories in Jordan.

The risk of cross-infection in dental clinics and laboratories has attracted the attention of practitioners for the past few years, yet several medical centers have discarded compliance with infection control guidelines, resulting in a non-safe environment for research and medical care. In Jordan, there is lack of known standard infection control programs that are conducted by the Jordanian Dental Technology Association and routinely practiced in commercial dental laboratories. The aim of this study was to examine the knowledge and practices in infection control among dental technicians working in commercial dental laboratories in Jordan. Data were collected from the dental technicians by a mailed questionnaire developed by the author. The questionnaire asked respondents to provide demographic data about age and gender and to answer questions about their knowledge and practice of infection control measures: use of gloves, use of protective eyeglasses and face shields, hepatitis B virus (HBV) vaccination, laboratory work disinfection when sent to or received from dental offices. and regularly changing pot water or pumice slurry. Of the total respondents, 135 were males (67.5 percent) and sixty-five were females (32.5 percent) with a mean age of twenty-seven years. The results showed that 24 percent of laboratory technicians wore gloves when receiving dental impressions, while 16 percent continued to wear them while working. Eyeglasses and protective face shields were regularly worn by 35 percent (70/200) and 40 percent (80/200) of technicians, respectively. Fourteen (14 percent) had received an HBV vaccination, and 17 percent inquired if any disinfection measures were taken in the clinic. Eighty-six percent of the technicians reported that pumice slurry and curing bath water were rarely changed. Only five dental technicians (two males and three females) were considered to be fully compliant with the inventory of infection control measures, a compliance rate of 2.5 percent with no significant difference between males and females (p>0.05). In conclusion, there is lack of compliance with infection control procedures of dental technicians working in commercial laboratories in Jordan.

A survey of localized lesions of oral tissues: a clinicopathological study.

OBJECTIVE: The purpose of this study was to establish the relative prevalence of the different histopathological aspects of biopsied localized soft tissue oral lesions in a university-based dental school biopsy service. STUDY DESIGN: A retrospective analysis of patients' records with localized lesions treated in the Department of Oral Medicine and Oral Surgery between 2001 and 2004 was conducted. The lesions were classified into either fibrous lesions or soft hemorrhagic lesions. Clinical data regarding age, gender, location, and treatment of the lesions were obtained for each case. RESULTS: The majority of the lesions were located in the gingiva. There were a total of 294 cases of which 182 (61.9%) were fibrous lesions and 112 (38.1%) were soft hemorrhagic lesions. All cases were treated by excisional biopsy and elimination of the chronic irritant. CONCLUSION: Although this data might be used as a guide for forming clinical impressions about oral lesions, the clinician must always be aware of the possible occurrence of more rare lesions. This study indicates there are some differences in age and gender distribution as well as in location between the different lesions.

Compliance with infection control programs in private dental clinics in Jordan.

The aim of this study was to assess the compliance of general dental practitioners (GDPs) in the private sector in North Jordan with infection control measures. A pilot-tested questionnaire about infection control measures was distributed in March 2004 to 120 private practices. The response rate was 91.66 percent. About 77 percent of dentists usually ask their patients about medical history, 36 percent were vaccinated against hepatitis B, 81.8 percent wear and change gloves during treatment and between patients, and 54.5 percent wear and change masks during treatment and between patients. Most dental practitioners (95.4 percent) reported that they changed extraction instruments and burs between patients. All dental practitioners reported that they changed saliva ejectors between patients, but only 41.8 percent changed handpieces between patients. Approximately 63 percent (69/110) used autoclaves for sterilization, 47.3 percent (52/110) used plastic bags to wrap sterilized instruments, and only 18 percent (20/110) disinfected impressions before sending them to dental labs. Fourteen percent used rubber dams in their clinics, and only 31.8 percent had special containers for sharps disposal. Based on these responses, approximately 14 percent of general dentists in this sample were considered to be compliant with an inventory of recommended infection control measures. In Jordan, there is a great need to provide formal and obligatory infection control courses and guidelines for private dentists by the Ministry of Health and the dental association in addition to distribution of standard infection control manuals that incorporate current infection control recommendations.

Cheating behaviors of dental students.

There has always been some degree of cheating in educational institutions. Many students who have difficulty retaining information, or who are just too lazy to work, turn to cheating as an easy way to obtain high marks. The aims of this study were to investigate undergraduate dental students' attitudes about the seriousness of thirteen cheating behaviors and to determine the students' attitudes about justification for cheating. A multiple choice questionnaire was distributed to 200 undergraduate dental students at the Faculty of Dentistry of the Jordan University of Science and Technology in the second through the fifth year of the curriculum in order to rate thirteen cheating behaviors and report their degree of satisfaction with studying dentistry. The response rate was 100 percent. Nine out of the thirteen cheating behaviors were considered as serious by about 85 percent of students. This majority also reported that they enjoyed studying dentistry compared to 10 percent who liked dentistry and 5 percent who disliked dentistry. Those 85 percent reported that they considered themselves to be ethical, while 10 percent selected somewhat ethical and 5 percent selected not ethical. This study revealed the importance of the issue of cheating and how it is evaluated by dental students who may benefit from educational programs as part of their curriculum.