Jack D. Gerrow

A Prospective Randomized Study on the Immediate Loading of Mandibular Overdentures Supported by One or Two Implants; A 3 Year Follow-Up Report

AIM The objective of the study was to evaluate and compare treatments with mandibular overdentures supported by one or two immediately placed implants 3 years after loading. MATERIALS AND METHODS Thirty-six edentulous subjects were eligible for inclusion. Using a random sampling system, one or two implants were placed in the mandible. Separate ball attachments were connected to the implants, and the denture was relined and delivered the day of surgery with the retentive components incorporated in the denture base. At the follow-up examinations peri-implant bone levels, implant and denture stability/retention, and need for maintenance and adjustments were evaluated. Moreover, the OHIP-EDENT questionnaire was used to measure patient satisfaction. RESULTS Nineteen subjects (10 men and 9 women) with a mean age of 56 years were available for the 3-year follow-up examination. The group with 1 implant (Group 1) consisted of 11 subjects (5 women and 6 men) while the remaining 8 (5 women and 3 men) belonged to Group2. Nine subjects had been excluded during the first year due to failing implants, 6 had moved, 1 had died, and 1 reported severe illness. No implant failures between the 12-and 36 month follow-up were observed. The mean peri-implant bone change was.86 mm and the Implant Stability Quotient showed only minor changes with no significant difference between the groups when compared with the 12-month follow-up. Patient satisfaction scores increased significantly when compared with the baseline values and continued to be high for both groups and need for denture maintenance was low. CONCLUSION No significant differences were found between subjects in the two groups with respect to implant survival and peri implant bone loss, and patient satisfaction scores continued to be high for both groups. Need for denture maintenance was low in both groups.

Evaluating the Bookmark Standard Setting Method: The Impact of Random Item Ordering.

Throughout the world, cut scores are an important aspect of a high-stakes testing program because they are a key operational component of the interpretation of test scores. One method for setting standards that is prevalent in educational testing programs—the Bookmark method—is intended to be a less cognitively complex alternative to methods such as the modified Angoff (1971) approach. In this study, we explored that assertion for a licensure examination program where two independent panels applied the Bookmark method to recommend a cut score on its Written Exam. One panel initially made their ratings using an ordered item booklet (OIB) in which items were randomly ordered with respect to empirically estimated difficulty followed by judgments on a correctly ordered OIB. A second panel applied the Bookmark process with only the correctly ordered OIB. Results revealed striking similarities among judgments, calling into question panelists’ ability to appropriately engage in the Bookmark method. In addition, under the random-ordering condition, approximately one-third of the panelists placed their bookmarks in a manner inconsistent with the new item difficulties. Implications of these results for the Bookmark standard setting method are also discussed.

Comparison of the surface detail reproduction of flexible die material systems

STATEMENT OF PROBLEM Flexible die materials have been introduced to facilitate the fabrication of indirect provisional or definitive restorations in 1 appointment. PURPOSE This study compared the surface detail reproduction of 7 potential flexible die materials when used in combination with 7 elastomeric impression materials. METHODS Surface detail reproduction of 17 impression material/flexible die material systems was compared with a control system containing an elastomeric impression material and a Type IV dental stone. Test dies of each system were prepared in a random order with the American Dental Association apparatus for testing detail reproduction, compatibility, and dimensional stability. RESULTS One flexible die system had better surface detail reproduction than the control stone die, other systems had similar or worse reproduction. Surface detail reproduction was adversely affected when a separator was required between the impression and flexible die material. CONCLUSIONS Impregum F die material with Extrude Light impression material produced better surface detail reproduction than the control dies. Impregum F impressions were incompatible with Blu-Mousse, Impregum F, or Imprint die materials. Polyvinyl siloxane impressions were incompatible with polyvinyl siloxane dies unless a separator was used. When a separator was used, the surface detail reproduction was not as good as the control die system or the Extrude Light impression material/Impregum F die material combination.

Satisfaction and Clinical Outcomes Among Patients with Immediately Loaded Mandibular Overdentures Supported by One or Two Dental Implants: Results of a 5-Year Prospective Randomized Clinical Trial

PURPOSE The purpose of this study was to evaluate patient satisfaction and clinical outcomes among subjects with mandibular overdentures supported by one or two immediately placed dental implants 5 years after loading. MATERIALS AND METHODS Thirty-six subjects (16 men and 20 women) received one or two dental implants in the anterior mandible, and all implants were loaded the day of surgery. Subjects were scheduled for follow-up 3-, 6-, and 12 months after implant placement and thereafter annually for 4 more years. Patient satisfaction scores were measured with the Oral Health Impact Profile-EDENT (OHIPEDENT) questionnaire. RESULTS Seventeen subjects (7 male and 10 female) with a mean age of 59.4 years (range, 44 to 74 years) were available for the 5-year follow-up examination. Nine subjects with 10 failing implants were excluded during the first year and nine subjects were lost to follow-up. No implants failed between the 12- and 60-month follow-up examinations, and the need for denture maintenance was low. Mean peri-implant bone change was 0.92 mm, and the Spearman test failed to show correlation between the insertion torque value and implant stability quotient. Patient satisfaction scores increased significantly when compared with baseline values and continued to be high for both groups, with no significant differences. CONCLUSION Ten implants in nine subjects failed early, but no failures were observed after the 12-month examination. No significant differences were found between subjects in the two groups with respect to implant survival rates and peri-implant bone loss, and patient satisfaction scores continued to be high. Although patient satisfaction and implant success were high during the 12- to 60-month period, the results should be interpreted with caution because of the high number of failing implants and patients lost to follow-up. More research is needed to study outcomes of treatment with immediately loaded mandibular implant overdentures.

Potential errors when using a computerized pantograph

This study determined the effect on articulator settings of using an arbitrary hinge axis as compared with the terminal hinge axis in orienting a computerized pantograph on a patient. The effect of an error in measuring the reference plane angle or clutch angle was also determined. Two subjects were pantographed 30 times by using the terminal hinge axis and 30 times by using the arbitrary hinge axis. Statistically the articulator settings obtained by using the arbitrary hinge axis and the terminal hinge axis were different, but the difference was small. One subject was pantographed on 18 occasions by using different reference plane angle and clutch angle settings. Analysis showed that 1-degree change in the reference plane angle setting produced approximately 0.9-degree change in the protrusive and orbiting path articulator settings. A 1-degree change in the clutch angle setting produced approximately 0.9-degree change in the progressive side shift settings. It was concluded that the terminal hinge axis should be used as the posterior reference point and the reference plane angle and clutch angle should be carefully recorded.

Margin adaptation of indirect composite inlays fabricated on flexible dies

STATEMENT OF PROBLEM Indirect composite restorations can be made in 1 appointment using a flexible die. Interactions between different impression materials and flexible die materials may affect the accuracy of fit and margin adaptation of the restoration. PURPOSE This study compared the margin adaptation of composite inlays made using the following 5 impression/flexible die material combinations; condensation silicone/polyvinyl siloxane (CS/PVS), wash viscosity polyvinyl siloxane/medium or heavy viscosity polyvinyl siloxane (PVS/PVS), irreversible hydrocolloid impression/medium viscosity polyvinyl siloxane (IH/PVS), wash viscosity polyvinyl siloxane impression/polyether (PVS/PE), with composite inlays made using a control system of a wash viscosity polyvinyl siloxane impression and a type IV stone die. MATERIAL AND METHODS For each test and control system, 10 impressions were made of a class II composite inlay preparation in a metal master die. One die was made from each impression and one composite inlay was made and finished on each die (a total of 60 inlays). Inlays were placed on the master die and the margin opening at the buccal, distal, and gingival sites was recorded with a measuring microscope (x40 magnification). RESULTS The overall mean +/- SD margin openings of inlays made from the systems were as follows: PVS wash/PVS heavy viscosity 149.5 +/- 107. 4 microm; PVS wash/PVS medium viscosity 87.4 +/- 63.0 microm; IH/PVS medium viscosity 76.7 +/- 48.9 microm; CS/PVS 73.3 +/- 48.7 microm, PVS wash viscosity/PE 64.0 +/- 44.3 microm, PVS wash viscosity/stone 53.9 +/- 48.3 microm. Composite inlays made using the PVS wash viscosity/PVS heavy viscosity system had significantly larger distal, gingival, and overall mean margin openings than all other inlays (ANOVA and Fisher PLSD test; P =.05). The separating medium required between some impression and die materials did not work consistently. Composite inlays fabricated on dies made of material different than the impression material had mean buccal, distal, gingival, and overall margin openings < or =100 microm. CONCLUSION Composite inlays made on the CS/PVS, IH/PVS medium viscosity, PVS wash viscosity/PE flexible dies, and control PVS wash viscosity/stone dies had statistically similar (P =.05) mean buccal, distal, gingival, and overall mean margin openings that were < or =100 microm. Composite inlays made on dies that were made of the same type of material as the impression material (PVS/PVS) had mean gingival margin openings >100 microm that were significantly larger than all other systems tested (P =.05).

Clinical evaluation in prosthodontics: Practical methods to improve validity and reliability at the undergraduate level☆

The potential causes of reliability and validity problems with traditional methods of evaluating a students clinical prosthodontic skills are reviewed. Practical methods of evaluating critical skills in a reliable and valid way are presented. These methods include clinical tests using written criteria and anonymous examiners, skills assessment by faculty members, patient-based written examinations, and bell ringer examinations.

Use of mouthguards during tooth preparation for extreme tooth hypersensitivity

During tooth preparation, the air and water from a dental handpiece occasionally cause painful stimulation of hypersensitive teeth. Use of mouthguards may be an alternative for the management of patients with tooth hypersensitivity.

Tips form our readersUse of mouthguards during tooth preparation for extreme tooth hypersensitivity

During tooth preparation, the air and water from a dental handpiece occasionally cause painful stimulation of hypersensitive teeth. Use of mouthguards may be an alternative for the management of patients with tooth hypersensitivity.