Personality, learning styles and handedness: The use of the non-dominant hand in pre-clinical operative dentistry training.

AIM: This research was undertaken with the aim of using personality traits, learning styles and handedness to develop and evaluate a scale to measure a new concept in operative dentistry, symmetrisation. An initial hypothesis was proposed, stating that handedness, personality trait and learning style could be used to predict symmetrisation potential in the domain of operative dentistry. METHODS: Participants completed three questionnaires: the Edinburgh handedness inventory assessment; the Keirsey Temperament Sorter-II (KTS-II); and the learning style assessment (VARK). Then, participants prepared a cavity on an artificial third molar tooth in the traditional phantom head using their non-dominant hand. For evaluation and comparison purposes, Standard Tessellation Language images were obtained from prepared teeth using a CAD/CAM scanner and then aligned against a reference "unprepared" tooth image using a custom software developed by the authors based on the Iterative Closest Point algorithm. RESULTS: Extroverts, intuitive and participants characterised as relying on their feelings were more accurate compared to introverts, sensory and toughminded participants, respectively. Extroverts were faster to complete the task compared to introverts. Participants with a preference for read/writing learning style produced more errors than any of the other groups. Handedness, however, did not show any significant association with performance. CONCLUSIONS: It was concluded that both the KTS-II and the learning style assessment (VARK) questionnaires possess potential as useful measures of symmetrisation potential and the ability to use the non-dominant hand in operative dentistry, as well as platform for continuing research.

Accuracy evaluation of intraoral optical impressions: A clinical study using a reference appliance.

STATEMENT OF PROBLEM: Trueness and precision are used to evaluate the accuracy of intraoral optical impressions. Although the in vivo precision of intraoral optical impressions has been reported, in vivo trueness has not been evaluated because of limitations in the available protocols. PURPOSE: The purpose of this clinical study was to compare the accuracy (trueness and precision) of optical and conventional impressions by using a novel study design. MATERIAL AND METHODS: Five study participants consented and were enrolled. For each participant, optical and conventional (vinylsiloxanether) impressions of a custom-made intraoral Co-Cr alloy reference appliance fitted to the mandibular arch were obtained by 1 operator. Three-dimensional (3D) digital models were created for stone casts obtained from the conventional impression group and for the reference appliances by using a validated high-accuracy reference scanner. For the optical impression group, 3D digital models were obtained directly from the intraoral scans. The total mean trueness of each impression system was calculated by averaging the mean absolute deviations of the impression replicates from their 3D reference model for each participant, followed by averaging the obtained values across all participants. The total mean precision for each impression system was calculated by averaging the mean absolute deviations between all the impression replicas for each participant (10 pairs), followed by averaging the obtained values across all participants. Data were analyzed using repeated measures ANOVA (α=.05), first to assess whether a systematic difference in trueness or precision of replicate impressions could be found among participants and second to assess whether the mean trueness and precision values differed between the 2 impression systems. RESULTS: Statistically significant differences were found between the 2 impression systems for both mean trueness (P=.010) and mean precision (P=.007). Conventional impressions had higher accuracy with a mean trueness of 17.0 ±6.6 µm and mean precision of 16.9 ±5.8 µm than optical impressions with a mean trueness of 46.2 ±11.4 µm and mean precision of 61.1 ±4.9 µm. CONCLUSIONS: Complete arch (first molar-to-first molar) optical impressions were less accurate than conventional impressions but may be adequate for quadrant impressions.

Survival of short dental implants for treatment of posterior partial edentulism: a systematic review.

PURPOSE: Dental implant therapy for posterior partial edentulism may utilize short implants. The advantages of short implants include the ability to avoid the additional surgical procedures that would be required to place longer implants. The aim of this study was to systematically review studies concerning dental implants of ≤ 8.5 mm placed in the posterior maxilla and/or mandible to support fixed restorations. MATERIALS AND METHODS: English-language articles published between 1992 and May 2011 were identified electronically and by hand search of the PubMed, Embase, and Cochrane libraries. Data were extracted and compared statistically. Forest plots were generated to compare outcomes of short versus long implants. RESULTS: An initial screening of 1,354 studies led to direct evaluation of 401 articles. Of these, 33 met the research criteria: 5 randomized clinical studies; 16 prospective, nonrandomized, noncontrolled studies; 12 retrospective, nonrandomized studies; and 1 study with both prospective and retrospective data. These studies indicated that there is no significant difference in the reported survival of short versus long implants. Failure of 59 of 2,573 short implants at 1 year was recorded, with 71% of them failing before loading. Only 101 short implants were followed for 5 years. CONCLUSIONS: The initial survival rate for short implants for posterior partial edentulism is high and not related to implant surface, design, or width. Short implants may constitute a viable alternative to longer implants, which may often require additional augmentation procedures.