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PurposeTo evaluate the effectiveness of the prosthetic rehabilitation, as well as the quality of life (QOL) of older edentulous maxillectomy patients.MethodsEffectiveness of the complete denture obturator prosthesis and QOL of 44 older patients who had resection of the maxilla and were restored with a definitive prosthesis that was in use for minimum 1 year was assessed using 3 instruments: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30), Head and Neck Cancer Module (QLQ-HN35), and Obturator Functioning Scale (OFS). Data analysis was performed by the one-way ANOVA on ranks, Spearman rank order correlation, and hierarchical multivariable rank regression at α=.05 level of significance.ResultsParticipants’ gender (PP =.016), surgical approach (P =.017), size of the maxillary defect (P=.028), participants’ prosthetic history (P =.047), and dental status of the mandible (P =.038) were significantly related to the self-reported effectiveness of the obturator. Perceived functioning of the complete denture obturator prosthesis (P=.001), participants’ gender (P=.002), the American Society of Anesthesiologists (ASA) physical status (P=.027), and surgical approach (P=.039) were significant predictors of QOL. ConclusionRestoration of the edentulous maxillectomy defect is challenging. An effective definitive complete denture obturator appeared to be the strongest predictor for advanced quality of life in older maxillectomy patients. The physical status of the older participants significantly affected the overall QOL, but did not influence the self-reported functioning of the complete denture obturator prosthesis.

Purpose The immediate application of a dentin-bonding agent after tooth preparation and before impression-taking (immediate dentin sealing [IDS]) has been suggested to provide several advantages concerning bacterial microleakage, hypersensitivity, and bonding quality. We reviewed the literature and clarified certain aspects related to each step of IDS application. Materials and Methods The search strategy comprised an electronic research in MEDLINE, Cochrane, Ovid and Scopus for studies published from January 1990 to December 2020 regarding the IDS technique and including both in vitro and clinical studies. Results After exclusion of irrelevant or duplicate articles, 88 articles focusing on aspects of the IDS technique were assessed. IDS seems to be advantageous with regard to bond strength, gap formation, bacterial microleakage, and dentin hypersensitivity. However, issues arising from interaction with impression materials, the provisional phase, and conditioning methods before cementation require further investigation. Conclusion There are no documented reasons preventing clinicians applying IDS in their everyday practice. On the contrary, the presented technique seems to be beneficial in certain aspects regarding indirect restorations.

To determine the effect of lifetime maxillofacial changes on dental implants placed in adults, analyze the clinical implications of these changes, identify prognostic factors, and offer possible solutions.The relationship between implant placement and maxillofacial changes, occurring during not only the active growth period but also the entire span of adulthood, has not been extensively examined. Vertical differences between implants and adjacent teeth due to the ankylotic behavior of the former might be observed at any age and endanger restoration biologically, functionally, and esthetically. Regarding interproximal contacts, firm contact loss may occur within a few months after restoration, resulting in food impaction. Many prognostic factors have been reported, but most do not exhibit a statistically significant association with implant infraocclusion and interproximal contact loss. Incorporation of alternative solutions, accurate treatment planning, strict recall protocols, and retrievability of implant-supported restorations can facilitate efficient management of complications.Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. Rehabilitation of edentulism should be characterized by well-designed and flexible treatment plans to resolve long-term complications efficiently. Further long-term clinical studies are needed to identify other risk factors.Treatment plans for implant therapy should be reconsidered for adults. Careful patient monitoring and early intervention are essential for securing treatment outcomes.

Aim The aim of this literature review is to determine whether endocrowns are a reliable alternative for endodontically treated teeth with extensive loss of tooth structure, the indications and contraindications of this restorative choice, the principles that should be followed for tooth preparation and which material is most appropriate for endocrown fabrication. Background Rehabilitation of endodontically treated teeth with severe coronal destruction has always been a challenge for the dental clinician. Until recently, the fabrication of a metal-ceramic or all-ceramic full-coverage crown along with a metal or glass fiber post has been the "gold standard" proving its efficacy via numerous clinical studies. With the development of CAD/CAM technology and the evolution of dental materials, new minimally invasive techniques have been introduced with less need for adjustments and less incorporation of structural defects. One of them, the "monoblock technique," proposed by Pissis in 1995, was the forerunner of endocrown restoration, a term used by Bindl and Mormann to describe an all-ceramic crown anchored to the internal portion of the pulp chamber and on the cavity margins, thus obtaining macromechanical retention provided by the axial opposing pulpal walls and microretention attained with the use of adhesive cementation. Review results Endocrowns require a decay-oriented preparation taking advantage of both the adhesion and the retention from the pulp-chamber walls, they are strongly indicated in endodontically treated molars in cases where minimal interocclusal space and curved or narrow root canals are present and they should be manufactured from materials that can be bonded to the tooth structure. Conclusion Endocrowns are a reliable alternative to traditional restorative choices, given that the clinicians respect the requirements and indications describing this technique. Clinical significance Traditional restorative techniques demanding tooth substance removal and minimizing the opportunity for reinterventions should be reconsidered.

The purpose of this study was to investigate the surface characteristics and color stability of gingiva-colored composite restorative materials (Anaxgum&mdash, ANG, Ceramage&mdash, CMG and Gradia Gum&mdash, GRG). The microstructure, composition, degree of conversion (DC %) and 3D roughness (Sa, Sz, Sdr, Sc) were examined by LV-SEM/EDS, ATR-FTIR and optical profilometry, respectively. For the color stability (CIE L*, a*, b* system) and hardness (HV), measurements were performed at baseline and after 30 days storage in distilled water, coffee and red wine. The ANG and GRG contain prepolymerized particles in aromatic and aliphatic resin matrices, respectively, whereas CMG contains inorganic zirconia silicate/silica particles, in an aromatic resin matrix, with a smaller particle size and a higher surface area fraction. Urethane monomers were mainly identified in CMG and GRG. The DC% showed statistically insignificant differences between the materials. The same applied for the roughness parameters, except for the greatest Sdr in CMG. ANG showed a color difference (&Delta, E) of &gt, 3.3 after immersion in all media, CMG in coffee and wine and GRG only in coffee. Sc was the only roughness parameter demonstrating correlations with the &Delta, L*, &Delta, b* and &Delta, E*. The HV values showed insignificant differences between the storage conditions per material. There are important differences in the color stability of the materials tested, which were mostly affected by the roughness parameters due to variations in their microstructure.

Aim: The precise framework fit is important for the success of implant restorations. The purpose of the present study was to examine the effect of two different impression materials both of their medium viscosity on the master cast accuracy when parallel and inclined implants were used. Materials and Methods: An epoxy master cast with three implants was fabricated. The first two implants were parallel to each other and perpendicular to the horizontal plane and the third implant had a 250 inclination in reference to the other two. A passively fitting metal framework that was fabricated over this master cast was used to measure accuracy of fit. Five closed tray impressions for each medium viscosity material (polyether and polyvinyl-siloxane) tested were taken and the respective ten stone casts with three implant analogs were fabricated. The metal framework in the master cast, was fixed in the new specimens and the micro-gap between this prosthesis and the implant analogs was evaluated. The specimens were observed to an optical microscope and digital photography. Results and Conclusion: The data were statistically analysed using a computer software and t-test. Polyether exhibited higher micro-gap mean values (93,4 to 61,8 μm) compared to polyvynil siloxane (30,47 to 14,83μm). The differences were statistically significant only for implant B. The categorical regression analysis (p < 0.01) for all implants showed that the marginal micro-gap was affected by the impression material (94.1%) and significantly by the type of it. The micro-gap values were higher for polyether compared to polyvinyl-siloxane. The torqued implant did not exhibit any statistically significant effect.

The objective of this study was to examine the effect of splinting of the impression copings on the accuracy of the cast when the open-tray technique is used. An epoxy master cast with 3 implants was fabricated. The first 2 implants were parallel to each other and perpendicular to the horizontal plane (implants A and B), and the third implant (implant C) had a 25-degree inclination. A passively fitting metal framework that was fabricated over this master cast was used to measure accuracy of fit. Ten casts were fabricated from this epoxy resin master cast with the use of polyether material and the open-tray technique. For the first 5 casts, the impression copings were splinted with dental floss and autopolymerizing acrylic resin; in the next 5 casts, the impression copings were not splinted. The metal framework in the master cast was fixed in the new specimens, and the microgap between this prosthesis and the implant analogs was evaluated. The specimens were observed under an optical microscope, and microgap measurements were made on photographs taken at a standardized magnification of 40×. The inclined implant C had the smallest mean microgap among the 3 implants, but the differences were not statistically significant. Microgaps for all 3 implants were smaller when they were splinted, but the difference from the mean of the nonsplinted counterpart was statistically significant only for the inclined implant. The results suggest that there is no clinical advantage in splinting the impression copings for parallel implants. On the other hand, when the implants are not parallel, splinting of the impression copings can result in greater accuracy of the fabricated cast.

Svrha: Svrha ovoga rada bila je procijeniti utjecaj termocikliranja na čvrstoću savijanja poliamidnog materijala za bazu proteze. Materijali i metode: Testiran je poliamidni protezni materijal (Valplast), a kao kontrola korišten je PMMA (Vertex). Trideset primjeraka svakog materijala izrađeno je za ispitivanje čvrstoće savijanja prema standardu ISO 1567. Svi su uzorci pripremljeni i čuvani 48 sati u vodi na temperaturi od 37 °C, a zatim su podijeljeni u tri jednake skupine (n = 10). Ispitivanje čvrstoće savijanja obavljeno je odmah nakon uranjanja u vodu te nakon termocikliranja (5 °C/55 °C, 2c/min.) poslije 3000 i 5000 ciklusa. Ispitivanje fleksibilnosti provedeno je na trima točkama u univerzalnom stroju za testiranje na brzini križanja od 5 mm/min. Konačna čvrstoća savijanja izračunata je formulom: FS = 3PL/2bd2. Dvosmjerna ANOVA s Tukeyjevim post hoc testom primijenjena je na razini .05 statističke značajnosti. Rezultati: tatistički značajno smanjenje čvrstoće savijanja zabilježeno je nakon termocikliranja poslije 3000 ciklusa za PMMA-e i 5000 ciklusa za oba materijala. Čvrstoća savijanja PMMA-e bila je značajno veća u odnosu na poliamid za sve ispitane uvjete (p < 0,05). Zaključak: Termocikliranje je vrlo nepovoljno djelovalo na čvrstoću savijanja materijala poliamida i materijala PMMA za bazu proteze., Objective: The aim of the present study was to evaluate the influence of thermocycling on the flexural strength of a polyamide base denture material. Materials and methods: A polyamide denture base material (Valplast) was tested, whereas a PMMA material (Vertex) was used as a control. Thirty specimens of each material were fabricated for flexural strength testing according to ISO 1567. They were prepared and stored in water at 37°C for 48 hours. The specimens of each material were divided into three equal groups (n=10). Flexural strength testing was performed immediately after water storage and after thermocycling (5°C / 55°C, 2 c/min) for 3000 and 5000 cycles. A three point flexural test was performed on a universal testing machine at a crosshead speed of 5 mm/min. The final flexural strength was calculated using the formula: FS = 3 PL/2 bd2. A two-way ANOVA with post-hoc analysis using Tukey’s procedure was applied at .05 level of statistical significance. Results: A statistically significant reduction in flexural strength was recorded after thermocycling at 3000 cycles for PMMA and at 5000 cycles for both materials. The flexural strength of PMMA was significantly higher compared to polyamide for all the conditions tested (p

Purpose: To assess clinical performance of bar-retained implant overdentures (IOs) with distally placed ERA attachments on four implants, and patient satisfaction after a followup period of 5 years in a convenience selection of 15 patients. Materials and Methods: Bar-retained IOs with distally placed ERA attachments were placed and clinically monitored. Encountered complications during a 5-year follow-up period were recorded; and a modified OHIP-14 questionnaire was used to assess patient satisfaction. Results: Implant and restoration survival rates of 97.5% and 100%, respectively, were recorded. The most common maintenance requirement was the replacement of ERA retentive elements. A high degree of patient satisfaction was reported. Conclusions: The proposed IO design is a reliable clinical treatment protocol associated with a high degree of patient satisfaction and minor prosthetic complications.

The visual determination of tooth color with standard shade guides is a subjective method of color communication, depending on variables such as the light source, the operator, and the tooth. The assessment of tooth color may be improved by the use of special devices such as colorimeters or spectrophotometers. However, the repeatability and the interdevice agreement of these devices have not been thoroughly investigated.The purpose of this study was to evaluate the effect of different illuminants (natural daylight, dental unit lamp, and daylight lamp) on the matching repeatability of 2 intraoral spectrophotometers (Easyshade and SpectroShade).The maxillary right central incisor and canine and the mandibular left central incisor of each of 10 dental students were measured by a single operator using both devices. The color of each tooth was assessed 3 times with each device under each of the 3 different illuminants (natural daylight, a dental unit lamp, and a daylight lamp). The device readings were expressed in Vitapan 3D-Master shade codes. Statistical analysis was performed and the level of agreement was assessed with the Spearman Correlation Coefficient.A particularly high to moderate level of agreement among the readings made under natural daylight, a dental unit lamp, and a daylight lamp was observed for both devices (P.01), suggesting that their matching repeatability was not completely satisfactory for clinical practice. A moderate and a moderate to high level of agreement was found among Easyshade readings when the 3 different illuminants were used. The level of agreement for the respective SpectroShade readings was particularly high to high (P.001). A particularly low level of agreement was found among the respective Easyshade and SpectroShade readings performed under any of the illuminants tested (P.05), suggesting poor interdevice reliability.The matching repeatability of both devices under natural daylight, a dental unit lamp, and a daylight lamp was not completely satisfactory for clinical practice. The effects of different illuminants seem to be more pronounced for Spectroshade than for Easyshade. The interdevice agreement between the 2 devices tested was poor, suggesting that the 2 devices were not compatible.

AIM. This paper is an attempt to compare and analyze the various mathematical models for defining the dental arch curvature of children in normal occlusion based upon a review of available literature. Background. While various studies have touched upon ways to cure or prevent dental diseases and upon surgical ways for teeth reconstitution to correct teeth anomalies during childhood, a substantial literature also exists, attempting to mathematically define the dental arch of children in normal occlusion. This paper reviews these dental studies and compares them analytically. Method. The paper compares the different mathematical approaches, highlights the basic assumptions behind each model, underscores the relevancy and applicability of the same, and also lists applicable mathematical formulae. Results. Each model has been found applicable to specific research conditions, as a universal mathematical model for describing the human dental arch still eludes satisfactory definition. The models necessarily need to include the features of the dental arch, such as shape, spacing between teeth and symmetry or asymmetry, but they also need substantial improvement. Conclusions. While the paper shows that the existing models are inadequate in properly defining the human dental arch, it also acknowledges that future research based on modern imaging techniques and computeraided simulation could well succeed in deriving an allinclusive definition for the human dental curve till now eluding the experts.

Objectives To investigate the colour stability of four indirect composite restorative materials after accelerated aging. Methods Four indirect composites (Gradia, Signum+, HFO and Adoro) were used. For each material, six specimens were prepared and subjected to accelerated aging (Suntest CPS+, Atlas, Chicago, IL, USA) according to ISO 7491. A Dr. Lange Microcolor Data Station colorimeter (Braive Instruments, Liege, Belgium) was used to measure specimen colour before and after aging. Measurements were performed according to the CIE L*a*b* system, and the mean L*, a* and b* values for each material were calculated. The equation DeltaE = [(DeltaL*)2 + (Deltaa*)2 + (Deltab*)2](1/2) was used to measure the total colour change (DeltaE), where DeltaL*, Deltaa* and Deltab* are the differences in the respective values before and after aging. One-way ANOVA were used to determine statistically significant differences in DeltaL*, Deltaa*, Deltab* and DeltaE. Results No statistically significant differences were found in DeltaL*, Deltaa*, Deltab* and DeltaE among the materials tested (PDeltaL*=.063; PDeltaa*=.521; PDeltab*=.984 and PDeltaE=.408). After aging, Gradia specimens showed an increase in lightness (DeltaL*=0.36) and a green-yellow shift (Deltaa*=-1.18, Deltab*=0.6), while Signum+ specimens exhibited an increase in lightness (DeltaL*=0.5) and a green-blue shift (Deltaa*=-0.9, Deltab*=-0.45). HFO specimens exhibited an increase in lightness (DeltaL*=0.75) and a green-yellow shift (Deltaa*=-1.3, Deltab*=0.06), and Adoro specimens exhibited an increase in lightness (DeltaL*=2.07) and a green-yellow shift (Deltaa*=-1.3, Deltab*=0.68). Conclusions Colour changes were found to be within accepted values of perceptibility and clinical acceptance after accelerated aging, and no statistically significant differences were found in DeltaL*, Deltaa*, Deltab* and DeltaE among the materials tested.

Implant treatment protocols for fully edentulous patients include implant-supported fixed restorations with a minimum of five to six implants or overdentures on two to four implants. However, implant placement in the posterior areas is sometimes not permitted by anatomic and/or financial restraints, or patients’ unwillingness to have extensive surgical procedures. The purpose of this case report is to present a treatment option where bilateral distal extension removable partial dentures (RPDs) are used in combination with anterior fixed implant prostheses with semi-precision attachments. The initial treatment plan of a 65-year-old female with failing dentition involved the fabrication of overdentures supported by four implants placed in the interforaminal area in both arches. Because of inadequate space for the retentive elements of the overdenture and the patient's objection to surgical procedures for the placement of additional implants to support a fixed restoration, the treatment plan was modified. Fixed ceramometal cement-retained implant restorations with semi-precision attachments adjacent to the distal abutments were fabricated in the maxilla and the mandible. Bilateral distal extension RPDs were placed in both arches. The patient's benefits were increased comfort, good esthetics in the anterior area, improved phonetics, and masticatory function. Retentive element maintenance requirements were similar to conventional RPDs. More extended controlled clinical studies are needed to establish the long-term success of this treatment option. CLINICAL SIGNIFICANCE Removable partial dentures may offer an attractive treatment option for an edentulous patient, as they may combine an FPD in the anterior segment with a removable appliance in the posterior areas. A satisfying restoration can be achieved with fewer implants.

Statement of Problem. Poor retention is a common cause of failure for resin-bonded restorations. Purpose. This study evaluated the effect of the convergence angle of tooth preparations on retention of resin-bonded restorations, luted with adhesive and conventional resinous cements. Material and Methods. A total of 80 posterior retainers with four different tooth preparation angles were cemented with two different resinous cements, and retentive strength was measured. Results. The results indicated that (1) increased tapering of tooth preparations resulted in loss of retention and this variable was statistically significant for both cements used when convergence angles exceeded 10 degrees and (2) sandblasted nickel-chromium retainers, combined with adhesive resins, should provide sufficient retention for posterior resin-bonded fixed partial dentures. (J Prosthet Dent 1997;77:475-81.)

Statement of problem There is a need for achieving reliable chemical bond strength between veneering composites resins and casting alloys through the use of simplified procedures. Purpose The purpose of this study was to examine the shear bond strength of an indirect composite resin to a Ni-Cr alloy, using 4 primers and 2 airborne-particle-abrasion procedures. Material and methods Fifty-six Ni-Cr (Heraenium NA) discs, 10 mm in diameter and 1.5 mm in height, were fabricated. Twenty-four discs were airborne-particle abraded with 50-μm Al2O3 particles, while another 24 were airborne-particle abraded with 250-μm Al2O3 particles. The following primers were applied on 6 discs of each airborne-particle-abrasion treatment group: Solidex Metal Photo Primer (MPP50, MPP250), Metal Primer II (MPII50, MPII250), SR Link (SRL50, SRL250), and Tender Bond (TB50, TB250). The Rocatec system was used on another 6 discs, airborne-particle abraded according to the manufacturer's recommendations, which served as the control group (R). Two more discs were airborne-particle abraded with 50-μm and 250-μm Al2O3 particles, respectively, to determine the Al content on their surfaces, without any bonding procedure. The indirect composite resin used was Sinfony. Specimens were thermally cycled (5°C and 55°C, 30-second dwell time, 5000 cycles) and tested in shear mode in a universal testing machine. The failure mode was determined with an optical microscope, and selected specimens were subjected to energy dispersive spectroscopy (EDS). Mean bond strength values were analyzed using 2-way ANOVA followed by Tukey's multiple comparison tests (α=.05) and compared to the control group using 1-way ANOVA followed by Tukey's multiple comparison tests (α=.05). Results The groups abraded with 50-μm particles exhibited significantly higher bond strength compared to the groups abraded with 250-μm particles. Group MPII50 exhibited the highest mean value (17.4 ±2 MPa). Groups MPP50, MPP250, and TB50, TB250 showed adhesive failures and significantly lower bond strength compared to group R. Groups MPII50, MPII250, and SRL50, SRL250 showed combination failures and no significant difference compared with group R. EDS revealed interfacial rather than adhesive failures. Conclusions Airborne-particle abrasion with 50-μm Al 2 O 3 particles may result in improved bond strength, independent of the primer used. The bond strength of Metal Primer II and SR Link specimens was comparable to that of specimens treated with Rocatec. (J Prosthet Dent 2008;99:377-387)

This study evaluated the color changes and amount of remaining C = C bonds (%RDB) in three dental composites after hydrothermal- and photoaging.The materials tested were Estelite sigma, Filtek Supreme and Tetric Ceram. Specimens were fabricated from each material and subjected to L* a* b* colorimetry and FTIR spectroscopy before and after aging. Statistical evaluation of the deltaL,* deltaa,* deltab,* deltaE and %deltaRDB data was performed by one-way ANOVA and Tukey's test. The %RDB data before and after aging were statistically analyzed using two-way ANOVA and Student-Newman-Keuls test. In all cases an alpha = 0.05 significance level was used.No statistically significant differences were found in deltaL*, deltaa*, deltaE and %deltaRDB among the materials tested. Tetric Ceram demonstrated a significant difference in deltab*. All the materials showed visually perceptible (deltaE1) but clinically acceptable values (deltaE3.3). Within each material group, statistically significant differences in %RDB were noticed before and after aging (p0.05). Filtek Supreme presented the lowest %RDB before aging, with Tetric Ceram presenting the lowest %RDB after aging (p0.05). The %deltaRDB mean values were statistically significantly different among all the groups tested. No correlation was found between deltaE and %deltaRDB.

Composite veneering materials are used as alternatives to porcelain in fixed prosthodontics. Mechanical retention of the resin on the metal framework has been associated with the formation of gaps at the resin/alloy interface, and failure of the restoration. Several chemical bonding systems have been introduced to promote resin adhesion. The purpose of the present study was to evaluate the shear bond strength of three photocured composites (Artglass, Solidex & Signum+) to a Ni-Cr alloy.72 wax disks covered with 150-mum diameter beads were cast and divided in two equal groups. In the first group, Metal Photo Primer was applied on the casting surface, while the Siloc system was used in the second. Each group was divided in three subgroups of 12 samples, in which the three composites were photocured. Half of the specimens of each subgroup were subjected to 1000 and 5000 thermal cycles (5 and 55 degrees C) respectively. All specimens were tested in shear in a universal testing machine. The Siloc-Solidex group showed the highest bond strength (17.3 +/- 3.7 MPa). No statistically significant difference was found between specimens treated with Metal Photo Primer or Siloc. Thermocycling did not significantly affect the bond strength values. Solidex showed an adhesive failure mode for both alloy surface treatments, while Artglass and Signum+ exhibited combination failures. Conclusively, the appropriate alloy surface treatment - resin combination can significantly improve the resin-alloy shear bond strength. Specifically, Solidex resin exhibited significantly higher bond values compared with Artglass and Signum+, for both surface treatments and thermocycling procedures.