Amara Abreu

Complications and Solutions in Presurgical Nasoalveolar Molding Therapy

Objective: To outline three main categories of nasoalveolar molding complications, describe their etiologies and manifestations, and prescribe preventive and palliative therapy for their proper management. Estimates of the incidence of each complication also are provided. Materials and Methods: Data were collected retrospectively from the charts of 27 patients with complete unilateral cleft lip and palate treated by the first author (D.L.-B.) at the University of Puerto Rico (n  =  12) and the Medical College of Georgia (n  =  15). Confidence intervals for the true incidence of each complication were calculated using exact methods based on the binomial distribution. A significance level of .05 was used for all statistical tests. Results: Of the soft and hard tissue complications considered, only one (tissue irritation) had an estimated incidence greater than 10%. Compliance issues were of greater concern, with an estimated incidence of 30% for broken appointments and an estimated incidence of 26% for removal of the nasoalveolar molding appliance by the tongue. Conclusions: Although benefits outnumber the complications, it is important to address all complications in order to prevent any deleterious outcomes.

Tensile bond strength of an adhesive resin cement to different alloys having various surface treatments

STATEMENT OF PROBLEM The ability of a resin cement to bond to a restorative alloy is critical for maximal crown retention to nonideal preparations. Surface treatment and metal type may have an important role in optimizing resin-to-metal strength. PURPOSE The purpose of this study was to examine the effect of surface pretreatment on the tensile strength of base and noble metals bonded using a conventional resin cement. MATERIAL AND METHODS Cylindrical plastic rods (9.5 mm in diameter), cast in base (Rexillium NBF) or noble metal (IPS d.SIGN 53), were divided into rods 10 mm in length (n=10-12). Specimens were heated in a porcelain furnace to create an oxide layer. Test specimens were further subjected to airborne-particle abrasion (50-microm Al(2)O(3) particles) alone or with the application of a metal primer (Alloy Primer). Similarly treated rod ends were joined using resin cement (RelyX ARC), thermocycled (x500, 5 degrees -55 degrees C) and stored (24 hours, 37 degrees C) before debonding using a universal testing machine. Debond strength and failure site were recorded. Rank-based ANOVA for unbalanced designs was used to test for significant interaction (alpha=.050). Each pair of treatments was compared separately for each metal (Bonferroni-adjusted significance level of .0083, overall error rate for comparisons, .05). The 2 metals were compared separately for each of the 3 treatments using an adjusted significance level of .017, maintaining an overall error rate of .05. A multinomial logit model was used to describe the effect of metal type and surface pretreatment on failure site location (alpha=.05). RESULTS Interaction between metal type and surface pretreatment was significant for stress values (P=.019). Metal type did not significantly affect tensile bond strength for any of the compared surface pretreatments. Metal primer significantly improved tensile bond strength for each metal type. Most failures tended to occur as either adhesive or mixed in nature. CONCLUSIONS Metal primer application significantly enhanced tensile bond strength to base and noble metal. No significant differences in tensile strength were found between alloys. Differences in failure site incidence were found to be related to metal type and surface pretreatment.

Oral rehabilitation of a patient with complete unilateral cleft lip and palate using an implant-retained speech-aid prosthesis: Clinical report

Objective: To report the oral rehabilitation of velopharyngeal insufficiency due to a congenital anatomic defect using an implant-retained speech-aid prosthesis. Case Report: A 65-year-old man with a diagnosis of complete unilateral cleft lip and palate on the left side with an unrepaired palate was examined. A removable partial denture with a speech bulb had been used for approximately 40 years. After primary care for gross caries and tooth mobility, an implant-retained obturator with a speech bulb was fabricated. Results and Conclusion: Improvement in mastication, speech, and velopharyngeal function was achieved with a satisfactory esthetic result.

Effect of metal type and surface treatment on in vitro tensile strength of copings cemented to minimally retentive preparations

STATEMENT OF PROBLEM Due to the potential lack of ideal preparation form, the type of alloy and its surface pretreatment may have clinically relevant correlations with the retentive strength of castings to minimally retentive preparations. PURPOSE The purpose of this study was to evaluate the effect of alloy type and surface pretreatments of base and noble metal copings on their tensile strength to minimally retentive preparations. MATERIAL AND METHODS Minimally retentive, standardized crown preparations were made on recently extracted human third molars (n=68). Noble (IPS d.SIGN 53) and base metal (Rexillium NBF) copings were fabricated. All copings received heat treatment for oxide formation. Three experimental groups were then developed for each metal type (groups ranging from 10 to 12 specimens each): oxide only, airborne-particle abraded, or metal-primed. Copings were cemented using a self-adhesive universal resin cement (RelyX Unicem) and were thermal cycled (500 cycles between 5 and 55 degrees C) and stored (24 hours, 37 degrees C) before debonding using a universal testing machine. Frequency of debond location was compared among specimen groups. A 2-way ANOVA was used to test for interaction between the metal type and surface treatment, and, if no significant interaction was found, to test the main effects for metal type and surface treatment (alpha=.05). A multinomial logit model using the likelihood ratio test was used to describe the effect of metal type and surface treatment on failure site location (alpha=.05). RESULTS The 2-way ANOVA indicated no significant influence of any factor on debond load: metal type (P=.885), surface treatment (P=.555), or their interaction (P=.644). The multinomial logit statistical model showed that noble metals and metal primers significantly (P<.05) shifted debond failures to occur more frequently at the resin/tooth interface or within the tooth itself. CONCLUSIONS Neither metal type nor surface pretreatment affected bond strength. However, alloy type and surface treatment affected site of debond location. (J Prosthet Dent 2007;98:199-207).

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.

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)

A Technique to Facilitate Tooth Modification for Removable Partial Denture Prosthesis Guide Planes.

The technique in this article was developed to provide a means to create prepared guide planes of proper dimension to ensure a more stable and retentive removable partial denture prosthesis (RPDP) framework when providing this service for a patient. Using commonly found clinical materials, a paralleling device can be fabricated from the modified diagnostic cast of the patients dental arch requiring an RPDP. Polymethyl methacrylate or composite added to an altered thermoplastic form can be positioned intraorally and used as a guide to predictably adjust tooth structure for guide planes. Since it can potentially minimize the number of impressions and diagnostic casts made during the procedure, this can help achieve the desired result more efficiently and quickly for the patient.

Interdisciplinary treatment of an adult with bilateral cleft lip and palate with missing premaxilla: The prosthodontic perspective

Conventional orthognathic surgery and orthodontic techniques occasionally fail to completely correct the occlusal relationship and esthetic deficits of patients with cleft lip and palate and severe midface deficiency. Prosthodontic rehabilitation is often required to establish adequate occlusion and provide a more proportional facial appearance. This clinical report describes the interdisciplinary management of an adult with complete bilateral cleft lip and palate who was treated with distraction osteogenesis using a rigid external distraction device for maxillary advancement and his prosthodontic rehabilitation with a dual path removable partial overdenture to develop definitive facial and dental esthetic form.

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.