Jimmy Londono

Fabrication of a definitive obturator from a 3D cast with a chairside digital scanner for a patient with severe gag reflex: A clinical report

Patient gagging is a common problem during dental procedures such as maxillary impression making. This clinical report describes the use of a chairside intraoral scanner for a patient with a hypersensitive gag reflex. The technique proved to be a more comfortable alternative for the patient and an accurate method for the clinician to capture both hard and soft tissue detail for the fabrication of a definitive obturator.

Accuracy and precision of as-received implant torque wrenches

STATEMENT OF PROBLEM Previous implant torque evaluation did not determine if the target value fell within a confidence interval for the population mean of the test groups, disallowing determination of whether a specific type of wrench met a standardized goal value. PURPOSE The purpose of this study was to measure both the accuracy and precision of 2 different configurations (spring style and peak break) of as-received implant torque wrenches and compare the measured values to manufacturer-stated values. MATERIAL AND METHODS Ten wrenches from 4 manufacturers, representing a variety of torque-limiting mechanisms and specificity of use (with either a specific brand or universally with any brand of implant product). Drivers were placed into the wrench, and tightening torque was applied to reach predetermined values using a NIST-calibrated digital torque wrench. Five replications of measurement were made for each wrench and averaged to provide a single value from that instrument. The target torque value for each wrench brand was compared to the 95% confidence interval for the true population mean of measured values to see if it fell within the measured range. RESULTS Only 1 wrench brand (Nobel Biocare) demonstrated the target torque value falling within the 95% confidence interval for the true population mean. For others, the targeted torque value fell above the 95% confidence interval (Straumann and Imtec) or below (Salvin Torq). CONCLUSIONS Neither type of torque-limiting mechanism nor designation of a wrench to be used as a dedicated brand-only product or to be used as a universal product on many brands affected the ability of a wrench to deliver torque values where the true population mean included the target torque level.

Effect of Vital Tooth Bleaching on Solubility and Roughness of Dental Cements

STATEMENT OF PROBLEM Vital tooth bleaching may affect properties of dental cements used for fixed prostheses. PURPOSE The purpose of this study was to examine the effect of a combined in-office and at-home bleaching regimen on changes in surface roughness and depth loss of a variety of commercially available dental cements. MATERIAL AND METHODS Five cement classifications were tested: glass ionomer, resin-modified glass ionomer, resin,self-adhesive resin cement, and zinc phosphate. Cements were placed in multiple wells in plastic blocks. After setting,the surface profile of each block was determined, and average roughness and vertical height of cement surface from the specimen holder were recorded. Blocks were water stored (control) or subjected to in-office and at-home bleaching(n=12). Surfaces were rescanned and pre- and posttest parameter changes were calculated. Statistical analysis consisted of Mann-Whitney-Wilcoxon Rank Sum and Student t tests applied to control and bleaching parameterc hanges within the same cements. A family-wise alpha of .05 was maintained by using a Bonferroni-adjusted level of significance preset to .01 per test. RESULTS Zinc phosphate showed the only significant depth increase (P=.004) from bleaching: 0.9 +/- 0.7 microm deeper than the water-control group. Only resin-modified glass ionomer showed a significant (P=.004) increase in roughness from bleaching; values increased by 0.05 +/- 0.03 microm over the water-control group. CONCLUSIONS In-office and at-home bleaching significantly increased depth loss of zinc phosphate and increased resinmodified glass ionomer roughness. However, the absolute values of differences observed, as compared to the wateronly control, were considered to be clinically insignificant. (J Prosthet Dent 2009;102:148-154)

Method for fabrication of a cast mounting device with interchangeable occlusal templates

A definitive impression technique using both impression wax and vinyl polysiloxane impression material for displaceable mandibular residual ridges is described. Consideration has been given to the choice of impression materials as well as to the design of the impression tray to minimize the amount of pressure exerted onto the displaceable regions of the residual ridges during the impression-making procedure. REFERENCES

Measuring the space required for symmetrical prosthetic restorations in the esthetic zone for an orthodontic patient: A dental technique

This article describes a technique for measuring the length of the edentulous space to be restored and transferring the same size of the dentate space on the contralateral side to plan for symmetrical definitive restorations for the restorative dentist and orthodontist. The technique involves incorporating 2 archwire locks with hooks on a stainless steel wire that can be easily moved and adjusted to assess the curved space being measured.

Use of an esthetic overdenture as an alternative treatment in a patient with bilateral cleft lip and palate

Stable occlusion and a pleasing esthetic appearance are often difficult to achieve in patients with congenital defects and severe midfacial deficiencies. Conventional therapy, such as orthodontic treatment followed by orthognathic surgery, is often not sufficient to fully correct the dental and esthetic problems. An interdisciplinary approach for these patients should include prosthodontic treatment that will assist in establishing a harmonious occlusion and improve facial appearance. This clinical report describes the interdisciplinary approach for a young patient with a history of bilateral cleft lip and palate, spina bifida, hydrocephalus, and ventriculoperitoneal shunt. The patient was treated with conventional orthodontic treatment and orthognathic surgery that failed to fully correct the malocclusion. A removable overlay prosthesis made of crystallized acetyl resin was used to reestablish esthetics and create a stable occlusion.

Digital design and 3D printing of an implant-supported prosthetic stent for protecting complete arch soft tissue grafts around dental implants: A dental technique

&NA; A method for digital fabrication of an implant‐supported soft tissue graft stent to protect, shape, and ensure intimate adaptation of the complete arch graft to the periosteum surrounding dental implants is described. To fabricate the stent, an extraoral scanner was used to convert the implant cast into digital data. Dental design software was then used to fabricate the stent, which is produced by 3‐dimensional (3D) printing. Due to the lack of long‐term biocompatible 3D printing material, the stent was duplicated in bisacryl resin. The patient reported more comfort and stability with the implant‐supported stent than the conventional stent received following a previous debulking surgical procedure.

Optimal Implant Position in the Aesthetic Zone

Planning for the optimal implant position in the aesthetic zone requires a thorough communication between the surgeon and the restorative dentist. The implant position is influenced by not only the anatomical morphology but also by the various prosthetic designs of the restoration. The mesial-distal, buccal-lingual, apical-coronal position, and angulation of the implants are all critical factors that will impact the emergence profile and material thickness of the prosthesis. This chapter will outline an interdisciplinary treatment approach to achieve the optimal implant position for the ultimate aesthetic and biologic outcome.

Digital design of a surgical guide for placement of definitive implants before orthodontic treatment.

Interdisciplinary treatment planning is an essential part of orthodontic therapy for patients with partial edentulism, especially when dental implants are to serve initially as anchorage and ultimately as prosthetic abutments for the definitive fixed restoration. A technique is presented for designing and fabricating a computed tomography-based surgical guide to place definitive implants before orthodontic therapy. First, the diagnostic cast and the orthodontic tooth arrangement and diagnostic waxing cast are scanned with a 3-dimensional optical scanner. Three-dimensional renderings of these scans are then merged and superimposed onto the cone beam computed tomography (CBCT) image with implant planning software to develop definitive implant positions. A custom surgical guide is fabricated from these data.

Fabricating short-term interim restorations from edentulous tissue conditioner material

Figure 1. Diagnostic waxing. The fabrication of interim restorations is a critical step in fixed prosthodontic treatment. In an extensive treatment, creating proper margins and adequate emergence profiles requires time and precision. However, if a rehabilitation appointment needs to be shortened unexpectedly and the relined interim shell still needs to be refined, the use of a short-term interim restoration is convenient for both the patient and clinician. This article describes a technique for fabricating a rapid and esthetic short-term interim device from a tissue conditioner and a vacuum-formed matrix. This alternative method comforts patients who are self-conscious and concerned about their dental esthetics during short intermissions such as lunch or lengthy breaks. It can also be used for those who do not tolerate long visits, allowing them to return on the following day so that overnight laboratory adjustments of the interim or of the definitive restorations can be completed. It is a useful and good backup technique for patients with fragile interim restorations likely to fail and is readily available in case of unscheduled emergencies. Tissue conditioning material is easy to mix, manipulate, and remove. Furthermore, the substance (CoeComfort; GC America) is white and reasonably simulates the natural dentition in the short term. It also covers the prepared teeth and minimizes their sensitivity. Because this material is used traditionally for tissue conditioning, it is biocompatible and not harmful to the gingival tissue. However, it should not be kept in place for more than 1 week because it may depress the interdental papillae when it hardens.