The effect of various preparation designs on the survival of porcelain laminate veneers.

PURPOSE: The aim of this clinical study was to observe the service duration of porcelain laminate veneers (PLVs) and to estimate the influence of the categorical covariates such as location, tooth vitality, preparation depth, incisal, gingival and proximal finishing lines, and peripheral tissue type on the survival rates of event-free and overall service duration. MATERIALS AND METHODS: A total of forty patients (26 women, 14 men; age range: 16 to 50) who had received 200 PLVs were evaluated in this study. Median follow-up time was 67.25 weeks with a range of 12 to 72 weeks. Fifteen of the restored teeth were nonvital, while the remaining 185 were vital. Categorical covariates related to the restoration design (localization, vitality, preparation depth, incisal, proximal, and gingival finishings, and surrounding tissue type) were recorded in order to estimate their influence on the survival rates. Survival rates of the event-free and overall service duration were calculated with the Kaplan-Meier analysis and Mantel log rank test. RESULTS: Twelve failures were observed. The most frequent failure type (11 units) was debonding of the restoration from the abutment tooth. Nine of them were rebonded and the remaining 2 were remade with a different preparation design. The last failure was observed as a coronal fracture at the cervical level. The overall survival rates were 99.5%, 99%, 97.5%, 94.9%, 94.4% and 93.8% at weeks 8, 9, 11, 15, 16, and 34, respectively, with a mean estimate of 68.45 weeks. CONCLUSION: PLVs exhibited good clinical results with their conservative specifications and high survival rates. The preparation and design specifications affect the service duration of PLVs.

Computed tomography-based planning and three-dimensional modeling for craniofacial implant placement: a technical note.

Facial defects can result from trauma, treatment of neoplasms, or congenital malformations, and their restoration is still a challenge for both surgeon and prosthodontists. Craniofacial implants can provide many benefits for prosthetic rehabilitation of facial defects; however, accurate placement of extraoral implants is vital for clinical success. Three-dimensional modeling is a novel technique that not only helps the surgeon to evaluate potential bone sites and adjacent structures, but also facilitates planning of the extraoral implant treatment by the prosthodontist. This technical report describes the use of three-dimensional modeling and planning for craniofacial implant placement.

Management of obstructive sleep apnea with a mandibular and tongue advancement splint (MTAS) in a completely edentulous patient. A clinical report.

Treatment of obstructive sleep apnea (OSA) in dentate patients using a mandibular advancement splint (MAS) from mandibular repositioners has been documented in detail. Nevertheless, studies about completely edentulous patients with OSA are sparse. This clinical report describes a clinical and laboratory method for producing a functional splint combining an MAS and a tongue-retaining device with an individualized tongue tip housing and discusses the rationale for using such a device.

Management of obstructive sleep apnea in an edentulous patient with a combination of mandibular advancement splint and tongue-retaining device: a clinical report.

BACKGROUND: Treatment of obstructive sleep apnea (OSA) in dentate patients by using mandibular advancement splint (MAS), had been documented in detail. Nevertheless, studies about completely edentulous patients with OSA are sparse. REPORT: This clinical report describes a clinical and laboratory method for producing a new functional splint combining a MAS and a tongue-retaining device with a custom-made tongue-tip housing and discusses the rationale for using such a device.

Heightened telescopic copings in cleft palate rehabilitation: a case report.

OBJECTIVE: To increase retention of overdentures in cleft palate patients by means of heightened telescopic copings with a newly designed attachment. In this study, a "precision attachment" is described to develop the stability and retention of telescopic overdentures. CASE: A cleft palate patient was treated with a newly designed overdenture. Intraoral examination revealed poor tooth structure and retention. Therefore, a new semiprecision attachment was designed in order to increase retention and stabilization. CONCLUSION: The patient's tolerance was increased with the new overdenture.

Effect of an adhesive resin luting agent on the dowel-head retention of three different core materials.

STATEMENT OF PROBLEM: A dowel-and-core restoration may fail due to failure at either the dowel-tooth or dowel head-core material interface. Long-term clinical success of a dowel-and-core restoration depends on retention of both the dowel to the tooth and the dowel head to the core material. Thus, strengthening of the dowel head-core interface is important. PURPOSE: This study evaluated the retention between a prefabricated dowel and 3 different core materials with or without a dual-polymerized adhesive resin luting agent. MATERIAL AND METHODS: Sixty prefabricated dowels (Gold Plated Anchorage Post) were divided into 3 groups (n=20) consisting of 1 of 3 core materials, amalgam (Standalloy F), light-polymerized resin composite (Clearfil Ray), or glass ionomer (Chelon-Silver). Each core group was divided into 2 subgroups (n=10), and a dual-polymerized adhesive resin luting agent (Panavia F) was applied to the dowel heads of 1 of these subgroups before application of the core material. The manufacturing procedure was standardized by using a plastic index (4.5-mm internal diameter and 5-mm height) and a custom-made dowel holder, which held the dowel head. Prepared specimens were stored in water at room temperature for 3 months and then loaded to fracture in a universal testing machine with a crosshead speed of 0.05 mm/min until failure. Bond strengths were recorded (MPa). Data were analyzed with 2-way analysis of variance (ANOVA) in a 2 x 3 factorial randomized design (alpha=.05). Afterward, core material differences were computed with 1-way ANOVA for both of the bonded and nonbonded groups. Post hoc multiple comparisons were made with the Dunnett C multiple range test. RESULTS: Dowel-head retention values (MPa) of the tested core materials (mean +/- SD) from the highest to the lowest were as follows: bonded amalgam core, 296.1 +/- 108; bonded composite core, 284.3 +/- 38.3; nonbonded composite core, 177.0 +/- 53.7; nonbonded amalgam core, 128.5 +/- 35.0; bonded glass-ionomer core (GIC), 128.0 +/- 24.5; nonbonded GIC, 61.8 +/- 13.3. Two-way ANOVA revealed significant differences between the core material groups and between the bonded and nonbonded groups (P <.001). The interaction between the core material and bond variables was also significant (P =.018). One-way ANOVA revealed statistically significant differences between the bonded (P <.001) and also between the nonbonded core material groups (P <.001). Post hoc multiple comparisons showed that the dowel-head retention of the GIC was significantly weaker than the post-head retention for amalgam and resin composite, whether bonded or not. CONCLUSION: Within the limitations of this study, the adhesive resin luting agent tested appeared to have a significant strengthening effect on the dowel-head retention of the core materials.

Fabrication of a sectional impression tray and sectional complete denture for a patient with microstomia and trismus: a clinical report.

This article describes techniques used to fabricate mandibular and maxillary sectional trays and a folding maxillary complete denture for a patient with limited oral opening caused by scleroderma. For the foldable denture, the anterior teeth had to be arranged on a second base and the hinge fitted at a location higher than the denture base. These 2 factors increased the thickness of the denture and limited the volume of the tongue. Nevertheless, a single-piece denture base provided the patient with ease in placement and removal of the denture.

Effect of different bonding agents on shear bond strengths of composite-bonded porcelain to enamel.

STATEMENT OF PROBLEM: The use of bonding agents in the luting procedure for porcelain laminate restorations to enamel is not clear. PURPOSE: This study evaluated the shear bond strength differences between an enamel-luting composite and a heat-pressed ceramic with 6 different bonding systems. MATERIAL AND METHODS: Seventy standardized heat-pressed IPS Empress ceramic discs (4-mm diameter, 3-mm height) were prepared. A vertical planar enamel-bonding surface was prepared on the buccal or lingual enamel of 70 freshly extracted sound human molars and premolars. The teeth were oriented to maintain a parallel relationship between the bonding plane and the shear loading axis of a universal testing machine. Tooth specimens were divided into 7 groups (n=10) comprising equal numbers of molars and premolars. The enamel surfaces of specimens in groups 1 through 6 were prepared with 1 of 6 bonding agents (Scotchbond Multi Purpose Plus, Heliobond, PQ1, SE Bond, Prime&Bond NT, and Prompt L-Pop). Finally, the specimens were luted to the ceramic discs with the composite cement (Opal Luting Composite). Ceramic discs in the seventh group (Control) were luted to the etched enamel with the composite cement without using bonding material. Enamel-ceramic specimens were kept in distilled water at room temperature for 30 days after cementation. All specimens were shear loaded axially in a universal testing machine with a crosshead speed of 0.05 mm/min until fracture. Shear bond strength was measured and recorded for each group in MPa. To determine the statistical significance of the differences between the mean shear bond strength values, a 1-way analysis of variance was used (alpha=.05). Post-hoc multiple comparisons were made with Duncan's multiple range analysis. Fractured surfaces of each specimen were also inspected with a stereomicroscope to evaluate failure modes. RESULTS: A 1-way analysis of variance revealed significant differences between the test groups (P=.00). Bond strength values (MPa) from the highest to the lowest were as follows: Prompt L-Pop, 25.46 +/- 5.6; Prime&Bond NT, 18.99 +/- 4.93; Heliobond, 17.28 +/- 4.0; SE Bond, 16.21 +/- 2.6; PQ1, 15.60 +/- 2.8; Scotchbond MPP, 14.82 +/- 2.4; and Control, 10.55 +/- 1.6. Duncan's multiple range post hoc analysis exhibited significant differences between the control group and the adhesive bonding agent groups (P<.05). There were also significant differences between the bonding agent groups (P<.05). Prompt L-Pop showed the highest bond strength values. CONCLUSION: Within the limitations of this study, bonding agents appear to have a strengthening effect on the shear bond strengths of the enamel/composite/porcelain interface of the materials tested. Bonding agents used in this study showed similar bond strength values except for Prompt L-Pop, which demonstrated the highest bond strength values.

Alternative method for connecting a removable gingival extension and fixed partial denture: a clinical report.

In terms of esthetics and hygiene, defects in the alveolar ridge can complicate the design and fabrication of fixed partial dentures. When missing anterior teeth are restored, it may be difficult to achieve a satisfactory appearance without the correction of soft tissue and alveolar defects. When surgical intervention is not an option, a removable gingival extension and fixed prosthesis may be considered. This clinical report describes the use of a custom-made pin system (rather than intra- or extra-coronal attachments) to esthetically connect a removable gingival extension to a fixed partial denture.