Using Electronic Dental Records to Assess Osteoradionecrosis Risk in Irradiated Head and Neck Cancer.

OBJECTIVE: Over the last 2 decades, investigations have demonstrated a decreased trend in the likelihood of osteoradionecrosis of the jaw (ORNJ) after extraction. The aim of this study was to explore the potential risk factors for ORNJ in irradiated head and neck cancer by using patients' electronic dental records (EDRs). METHODS: Patients diagnosed with head and neck cancer who had irradiation between January 2010 and December 2020 were included in this retrospective cohort analysis. Patient charts showing evidence of "head and neck cancer," "oral cancer," "radiotherapy," "radiation," and "oral complication" were identified by an informatics analyst querying the EDR. Subsequently, the charts were manually reviewed, and data quality was assessed on 3 dimensions: completeness, accuracy, and consistency. The patient, tumor, systemic condition/drug, oral condition, treatment/trauma, and radiation were all categorized as potential risk factors. RESULTS: A total of 359 patients were included. With the exception of radiation-related factors, we found that the data quality was generally sufficient to support the research. Multivariate logistic regression analysis demonstrated that the following factors were significant in predicting the occurrence of ORNJ development in irradiated head and neck cancer: smoking (odds ratio [OR], 9.0; 95% CI, 1.9 to 43.0; P = 0.006), steroid use (OR, 6.4; 95% CI, 1.3 to 30.8; P = 0.021), oral health status (OR, 23.7; 95% CI, 2.7 to 211.0; P = 0.005), and postirradiation extraction (OR, 3.8; 95% CI, 1.0 to 14.4; P = 0.050). CONCLUSIONS: A 10-y retrospective analysis of data from an EDR revealed that smoking, steroid use, poor oral status, and postirradiation extraction are all factors linked to an increased risk of developing ORNJ. The quality of EDR data may be systematically assessed by determining the completeness, accuracy, and consistency of the underlying data. Radiation-related factors in particular were poorly documented, highlighting the need for collecting or incorporating this information into the EDR. KNOWLEDGE TRANSFER STATEMENT: EDRs can be used to identify risk factors for developing ORNJ in irradiated head and neck cancer and can help clinicians with selecting treatments by incorporating risk and complication considerations.

Development of a model shade guide for primary teeth.

AIM: Large disparities in colour ranges and distribution between primary and permanent teeth make shade guides for permanent teeth unsuitable for primary teeth applications. The aim of the study was to develop a model shade guide for primary teeth. STUDY DESIGN: The Vita Easyshade intraoral spectrophotometer was used to determine colour at the middle labial/buccal third surface of 612 primary teeth of 102 patients. METHODS: Model shade guides, containing 1-16 tabs, were designed in CIELAB (DeltaE*) and CIEDE2000 (DeltaE') colour difference formulae using nonlinear optimization. The coverage error (DeltaECOV) was calculated as the mean of minimal colour differences between each of primary teeth and the "closest" shade tab. Results were analyzed using descriptive and analytical statistics. RESULTS: The coverage error of Vitapan Classical shade guide applied to the primary teeth evaluated was 4.2 (SD +/- 1.8). DeltaE*COV and DeltaE'COV values for model shade guides with 16 tabs were 1.8 and 1.3, respectively. The CIELAB coverage error of the model shade guide containing two tabs outperformed DeltaE*COV of Vitapan Classical. CONCLUSIONS: As compared with Vitapan Classical shade guide, significantly smaller coverage error was obtained in the model shade guide with the same number of tabs, designed via constrained nonlinear optimization.

Technique for fabricating a lightweight, urethane-lined silicone orbital prosthesis.

A technique is presented for packing an acrylic resin core and controlling the thickness of an orbital prosthesis with the use of an irreversible hydrocolloid matrix. This technique provides a durable core without damaging the orbital prosthesis mold and permits a controllable thickness and therefore a lighter prosthesis.

Effect of adhesive retention of maxillofacial prostheses. Part 2: Time and reapplication effects.

STATEMENT OF PROBLEM: The success of most non-implant-retained extraoral prostheses depends on retention derived from skin adhesives. Part 1 of this study found that Skin-Prep Protective Dressing improved the retentive properties of adhesives and that Secure(2) Medical Adhesive was stronger than Epithane-3. Part 2 investigates the application of a second layer of adhesive to the prosthesis, which was earlier noted to improve retention at later time periods. PURPOSE: This study measured the force needed to remove silicone elastomer strips with Secure(2) Medical Adhesive from the skin of human subjects. Testing was performed before and after the removal of the strips and reapplication of the adhesive. MATERIAL AND METHODS: Secure(2) Medical Adhesive was painted on silicone rubber strips and placed in a nonsequential random order of the 3 variables to 3 sites on the ventral forearms of 21 human subjects and tested over an 8-hour period. The bond strength was measured at 0, 4, and 8 hours. After a reapplication of adhesive over the existing adhesive, additional bond strength measurements were made at 4 and 8 hours. Testing was at 10 cm/min in an Instron. All subjects had Skin-Prep coating applied before adhesive application. RESULTS: Bond strengths for both single applications and reapplications of the adhesive were greater at 0 hours and became significantly weaker after the 4- and 8-hour periods. The second application of the adhesive produced the strongest bonds when measured at 4 hours (110 N/m). Bonding was significantly higher at 8 hours if a second application of adhesive was applied at 0 or 4 hours. CONCLUSION: The results of this study indicate that the bond strength of silicone elastomer to skin decreased over an 8-hour interval. After removal of the silicone rubber strip and reapplication of Secure(2) Medical Adhesive over the existing adhesive, bond strengths increased.

Effect of adhesive retention on maxillofacial prostheses. Part I: skin dressings and solvent removers.

STATEMENT OF PROBLEM: The success of most maxillofacial prostheses depends on retention by medical adhesives. Products such as Smith-Nephew's Skin-Prep (SP) are available that can be used on the skin that could improve prosthesis adhesion protective dressing. The removal of adhesive from the skin is also problematic, so solvents, such as Uni-Solve adhesive remover (US), are often used. PURPOSE: This study measured the removal force of silicone elastomer strips with 2 adhesives from the skin of human subjects during the day, as affected by the use of SP and US, and determined the site of adhesive failure. MATERIAL AND METHODS: Silicone rubber strips were applied in a predetermined random order to the ventral arm surfaces of 20 human subjects. US was applied to half the sites 1 day before testing. SP was also applied to half the sites just before Epithane-3 (E3) or Secure(2) Medical Adhesive (SMA) were used to adhere the strips. They were peeled from the skin 6 hours later in an Instron at a rate of 10 cm/min. RESULTS: A 3-way within-group MANOVA revealed significant differences without interactions between adhesives (SMA=96.3 N.m, E3=24.1 N.m; P<.0005) and between use or nonuse of SP (SP=65.8 N.m, no SP=54.6 N.m; P<.0005). The use of US was not significant (no US=61.8 N.m, with US=58.6 N.m; P=.197). SMA adhered to the prostheses, whereas E3 adhered to the skin, leaving a residue (Fisher exact test; P<.0003). CONCLUSION: The combination of SMA and SP showed the highest adhesive bond strength. Overall, SMA was 3 to 5 times more retentive than E3. SP improved adhesion of both SMA (15%) and E3 (27%). SMA was still far more retentive. US had no effect on retention. SMA remained on the prostheses, whereas E3 left a difficult-to-remove residue on the skin.

A combined direct dowel and indirect core technique.

The dowel-and-core restoration is indicated when inadequate tooth structure remains to retain an extracoronal restoration. A modified technique for fabricating the dowel and core combines the direct technique of forming the dowel in the actual channel with the indirect technique of creating an ideal core contour in the laboratory. This technique allows the operator to create an accurate and passive fit of the dowel pattern in the canal preparation. The technique also introduces the option of retrieving the dowel portion by utilizing a polyvinyl siloxane cast or liner. Further advantages of the technique are reduced chairside time and the ability to capitalize on the preparation of multiple teeth. The technique focuses efforts on achieving an accurate and passive fit of the dowel clinically while delegating the formation of the core to the laboratory.

Simplified methods for fabricating tissue-supported implant-retained overdentures with retention from a resilient liner.

Resilient denture liner materials can be useful for tissue-supported implant-retained overdentures. They allow physiologic movement of the denture toward the tissues. This article presents a technique that offers several advantages over other methods of fabricating the overdenture with a resilient liner, and of transferring the superstructure: the acrylic resin base and the heat-cured resilient liner material are cured simultaneously; superstructure blockout is performed in the laboratory instead of in the mouth, where blockout is difficult; and direct transfer of the superstructure bar is more accurate and eliminates possible fracture of the duplicated superstructure if formed in die stone.

Overdenture retention of four resilient liners over an implant bar.

STATEMENT OF PROBLEM: Resilient denture liners offer an alternative method of designing implant-retained overdentures. Space is provided in the overdenture to envelop the implant bar with a resilient liner to be applied chairside or processed in the laboratory. The degree of retention may vary and these materials change over time. PURPOSE: This study evaluated the retention on an implant/bar prosthesis with overdentures lined with 4 resilient denture lining materials, after cyclic insertion and removal over a simulated 1.5-year period. MATERIAL AND METHODS: Four implants were placed in a mandibular edentulous cast and a gold bar superstructure was made. Overdentures were processed in Lucitone-199 and Tokuyama, Luci-Sof, Molloplast-B, and PermaSoft (with and without sealer) lining materials, cured according to manufacturers' instructions. Each of 5 overdentures contained each liner and were cycled 2740 times (simulating 1.5 years of service at 5 insertions daily) in 37 degrees C water in an Instron at 20 cm/min. Insertion and retention force were measured. RESULTS: The 3 silicone rubber liners were 3 to 5 times more retentive than the plasticized acrylic liner initially. After cycling, Tokuyama soft liner (autopolymerized silicone) gained 14% retention, Luci-Sof (heat-cured silicone) gained 8%, Molloplast-B (heat-cured silicone) lost 12%, whereas PermaSoft (autopolymerized plasticized acrylic) with sealer lost 43%, and without sealer lost 60%. PermaSoft lining material also chafed and crumbled after cycling and was significantly less retentive in most statistical comparisons. CONCLUSIONS: All the silicone-based resilient liners retained the overdentures well. The plasticized acrylic was less retentive initially, and lost significant retention after 2740 cycles, compared with silicone-based resilient liners.