Natural Tooth Pontic Using Recent Adhesive Technologies: An Esthetic and Minimally Invasive Prosthetic Solution.

An implant-supported crown represents an established and validated option for single-tooth replacement; however, a restorative solution should be selected according to a wide number of factors including patient's desire, expectations, specific clinical conditions, and financial possibilities. The aim of this case report is to describe a conservative rehabilitation strategy for the replacement of a periodontally compromised mandibular incisor: the extracted natural tooth was used as a pontic bonded to adjacent elements with polyethylene fiber and resin composite. This way, a chairside fabrication of a resin-bonded fiber-reinforced prosthesis is possible, using the patient's own tooth. After showing a satisfactory functional and esthetic result, advantages and pitfalls of this technique along with available data on the literature regarding the natural tooth pontic are addressed. Both patients and clinicians should be aware of minimally invasive, successful solutions for single-tooth replacement; whether indicated or necessary, the natural tooth pontic technique leaves open other treatment options for the future.

Undetected Excess Cement at Marginal Areas of Zirconia Crown Copings: In Vitro Analysis of Two Luting Agents and Their Influence on Retention.

PURPOSE: To evaluate the amount of residual cement (ECL) around the margins of zirconia crown copings after careful luting and cleaning procedures and to investigate these factors in relation to two tested luting materials. MATERIALS AND METHODS: An experimental model of a maxillary arch was selected for this in vitro study. The maxillary first molar was prepared to receive an all-ceramic, single, full-crown restoration with a finish line located 1 mm below the artificial gingiva. After scanning of the prepared tooth, 20 paired zirconia coping-abutment assemblies were CAD/CAM fabricated. A slot in the model allowed for insertion and removal of the assemblies for each new test. Specimens were divided into two groups according to the cementation procedure: half (n = 10) were luted using a resin-modified glass-ionomer (RMGI) (Ketac-Cem Plus) (GI group), and the other half with a dual-curing self-adhesive resin agent (RelyX Unicem 2) (UN group). The substructures were loaded with cement, and a customized preseating device was adopted for preliminary reduction of excess. The zirconia copings were finally seated on their respective abutments located on the simulation model. A blinded investigator attempted to remove all excess cement with clinically available instruments. The amount of excess cement left in situ after cleaning procedures was weighed in grams. Dislodging forces of luted coping-abutment assemblies were obtained by using pull-off tests in a universal testing machine (crosshead speed of 0.5 mm/minute) after 24 hours of water storage. Means and standard deviations were calculated for ECL and for retention force values, and Mann-Whitney and ANOVA tests were carried out to detect significant differences (α = .05) among groups. RESULTS: Cement remnants were found in all specimens despite the cleaning procedures, with a typical distribution in interproximal areas. Mean ECL values for the GI and UN groups were 0.0079 ± 0.0060 and 0.0107 ± 0.0081, respectively. No statistically significant differences were found between tested cements (P = .3284). Removal stress values (MPa) were significantly higher (P = .0313) for the UN group (12.4 ± 6.5) than for the GI group (6.57 ± 4.69). CONCLUSION: Similar amounts of undetected cement remnants were discovered around the esthetic margins of zirconia crown copings regardless of cement type. The luting procedure using the self-adhesive resin cement provided significantly higher early retention values than the RMGI material.

Unexpected Complication Ten Years after Initial Treatment: Long-Term Report and Fate of a Maxillary Premolar Rehabilitation.

Full-coverage restorations represent a well-known rehabilitation strategy for compromised posterior teeth; in the last years, new ceramic materials like zirconia have been introduced and widely adopted for the prosthetic management of molar and premolar areas. A long-term follow-up of a maxillary premolar rehabilitation using a veneered zirconia crown is presented; after ten years of uneventful clinical service of the tooth-restoration complex, a serious complication-namely, a vertical root fracture (VRF)-occurred. An extended time lapse (9 years) between the end of restorative procedures and development of symptoms due to VRF has been observed. On the other hand, a complete functional and esthetic integrity of the zirconia crown (without chippings or crack development) is documented along the follow-up period. Due to periodontal breakdown and severity of fracture, the premolar was extracted. The illustrations of our late failure, aetiological factors, and available data on the literature regarding VRF are addressed. Patients and clinicians should be aware of potential occurrences of some long-term, serious complications when dealing with previously treated and/or structurally weakened teeth. The development of a VRF might be unexpected and might occur many years after the end of tooth rehabilitation, despite adoption of contemporary restorative protocols and techniques.

Minimally-invasive dental anesthesia: Patients' preferences and analysis of the willingness-to-pay index.

AIM: The aim of the present prospective study was to evaluate the impact of a computer-controlled anesthesia on patients' comfort and to investigate, through the willingness-to-pay (WTP) index, and patients' acceptance of this new technology. METHODS: Fifty patients undergoing a class I or II restorative procedure were enrolled. A computer-controlled device for anesthetic delivery was utilized, and a questionnaire on the level of discomfort and WTP was given to all patients. RESULTS: A total of 86% of participants declared less discomfort than that perceived during their last traditional procedure for pain control; 58% of patients were willing to pay an additional fee for a modern anesthesia technique, with a median WTP value of 20$. CONCLUSIONS: Computer-controlled systems for local anesthesia represent a relevant tool for reducing patients' discomfort during dental treatment. The WTP index helps to quantify its relevance.

Mechanical Properties of Elastomeric Impression Materials: An In Vitro Comparison.

Purpose. Although new elastomeric impression materials have been introduced into the market, there are still insufficient data about their mechanical features. The tensile properties of 17 hydrophilic impression materials with different consistencies were compared. Materials and Methods. 12 vinylpolysiloxane, 2 polyether, and 3 hybrid vinylpolyether silicone-based impression materials were tested. For each material, 10 dumbbell-shaped specimens were fabricated (n = 10), according to the ISO 37:2005 specifications, and loaded in tension until failure. Mean values for tensile strength, yield strength, strain at break, and strain at yield point were calculated. Data were statistically analyzed using one-way ANOVA and Tukey's tests (α = 0.05). Results. Vinylpolysiloxanes consistently showed higher tensile strength values than polyethers. Heavy-body materials showed higher tensile strength than the light bodies from the same manufacturer. Among the light bodies, the highest yield strength was achieved by the hybrid vinylpolyether silicone (2.70 MPa). Polyethers showed the lowest tensile (1.44 MPa) and yield (0.94 MPa) strengths, regardless of the viscosity. Conclusion. The choice of an impression material should be based on the specific physical behavior of the elastomer. The light-body vinylpolyether silicone showed high tensile strength, yield strength, and adequate strain at yield/brake; those features might help to reduce tearing phenomena in the thin interproximal and crevicular areas.

Effect of different dental articulating papers on SEMG activity during maximum clenching.

This study evaluated the influence of two different occlusal indicators (articulating papers of 40µm and 200µm) on muscular activity of the temporalis anterior (TA) and superficial masseter (MS) during maximum voluntary clenches (MVC), using surface electromyography (SEMG). It was hypothesized that an articulating paper positioned between dental arches during MVC elicits a different muscular activity compared with the occlusion on natural dentition (without the occlusal indicator). 30 healthy adult subjects with a complete, natural dentition were recruited; SEMG activity was recorded in the following experimental conditions: MVC with cotton rolls for standardization purposes; MVC on natural dentition; MVC onto the 40µm or 200µm paper indicator positioned on right or left side of the dental arch. Percentage Overlapping Coefficient (POC; separate values obtained for TA and MS), antero-posterior coefficient (APC) and total muscle activities (IMP) were the analyzed SEMG parameters. The use of an occlusal indicator statistically changed POC_TA, POC_MS and IMP median values (p<0.05). Both 40µm and 200µm occlusal papers did not significantly affect APC values (P=0.86). A pronounced asymmetric muscular activity has been recorded with the introduction of an interocclusal media. All indices of muscular activity did not differ between sexes (Kruskal Wallis test, P>0.05). In conclusion, the examined articulating papers affected two specific SEMG parameters (POC and IMP); the recorded muscular activity with the occlusal indicator varied regardless left or right side positioning, and independently from tested paper thicknesses.

Comparison of marginal fit of Lava CAD/CAM crown-copings with two finish lines.

PURPOSE: Marginal fit is valued as one of the most important criteria for the clinical quality and success of all-ceramic crowns. The aim of this in vitro study was to investigate the marginal fit of Lava Zirconia crown-copings on chamfer and shoulder preparations. METHODS: Two acrylic model teeth were selected to simulate the clinical preparations: one molar was prepared with a chamfer finish line (C) and one premolar was prepared with a rounded shoulder finish line (RS). Each resin model was duplicated 10 times using silicon-based impression material and poured in type IV dental stone for the fabrication of working dies. A total of 20 copings were divided into two groups (n = 10 for each finish line). Fifty measuring locations were chosen randomly along the margin on the dies and the gap width - vertical marginal discrepancy - was measured under a light microscope with a magnification of x100. Measurements were made without cementation. The mean marginal gap widths and standard deviations were calculated and a one-way analysis of variance (ANOVA) was performed for different types of preparations in order to detect differences (α = 0.05). RESULTS: The mean marginal gap was 30 ± 3 µm for the C group and 28 ± 4 µm for the RS group. The one-way ANOVA showed no statistical significant difference between the two groups (P = 0.23). CONCLUSIONS: Within the limitations of this study, the marginal discrepancies were all within the clinical acceptable standard set at 120 µm. Chamfer and shoulder preparations did not show differences regarding the gap dimension. CLINICAL SIGNIFICANCE: Bur design is an easily selected parameter before natural tooth preparation. Both tested finish lines are able to help clinicians in obtaining acceptable marginal fit values for the investigated zirconia copings.

Esthetic rehabilitation of anterior teeth with laminates composite veneers.

No- or minimal-preparation veneers associated with enamel preservation offer predictable results in esthetic dentistry; indirect additive anterior composite restorations represent a quick, minimally invasive, inexpensive, and repairable option for a smile enhancement treatment plan. Current laboratory techniques associated with a strict clinical protocol satisfy patients' restorative and esthetic needs. The case report presented describes minimal invasive treatment of four upper incisors with laminate nanohybrid resin composite veneers. A step-by-step protocol is proposed for diagnostic evaluation, mock-up fabrication and trial, teeth preparation and impression, and adhesive cementation. The resolution of initial esthetic issues, patient satisfaction, and nice integration of indirect restorations confirmed the success of this anterior dentition rehabilitation.

Inlay-retained fixed dental prosthesis: a clinical option using monolithic zirconia.

DIFFERENT INDIRECT RESTORATIONS TO REPLACE A SINGLE MISSING TOOTH IN THE POSTERIOR REGION ARE AVAILABLE IN DENTISTRY: traditional full-coverage fixed dental prostheses (FDPs), implant-supported crowns (ISC), and inlay-retained FDPs (IRFDP). Resin bonded FDPs represent a minimally invasive procedure; preexisting fillings can minimize tooth structure removal and give retention to the IRFDP, transforming it into an ultraconservative option. New high strength zirconia ceramics, with their stiffness and high mechanical properties, could be considered a right choice for an IRFDP rehabilitation. The case report presented describes an IRFDP treatment using a CAD/CAM monolithic zirconia IRFDP; clinical and laboratory steps are illustrated, according to the most recent scientific protocols. Adhesive procedures are focused on the Y-TZP and tooth substrate conditioning methods. Nice esthetic and functional integration of indirect restoration at two-year follow-up confirmed the success of this conservative approach.

Prosthetic restoration in the single-tooth gap: patient preferences and analysis of the WTP index.

OBJECTIVE: The objective of this study was to evaluate the preference of a patients' population, according to the index of willingness to pay (WTP), against two treatments to restore a single-tooth gap: the implant-supported crown (ISC) and the 3-unit fixed partial denture prosthesis (FPDP) on natural teeth. MATERIALS AND METHODS: Willingness to pay values were recorded on 107 subjects by asking the WTP from a starting bid of €2000 modifiable through monetary increases or decreases (€100). Data were collected through an individually delivered questionnaire. The characteristics of the population and choices made, the median values and WTP associations with socio-demographic parameters (Mann-Whitney and Kruskal-Wallis tests), correlations between variables (chi-square test in contingency tables) and significant parameters for predicting WTP values obtained in a multiple linear regression model were revealed. RESULTS: The 64% of patients expressed a preference for ISC, while the remaining 36% of the population chose the FPDP. The current therapeutic choice and those carried out in the past were generally in agreement (>70% of cases, P = 0.0001); a relationship was discovered between the anterior and posterior area to the same method of rehabilitation (101 of 107 cases, 94.4%). The WTP median values for ISC were of €3000 and of €2500 in the anterior and posterior areas, respectively. The smallest amount of money has been allocated for FPDP in posterior region (median of €1500). The "importance of oral care" for the patient was a significant predictor, in the regression model analysis, for the estimation of both anterior (P = 0.0003) and posterior (P < 0.0001) WTP values. The "previous therapy" variable reached and was just close to significance in anterior (P = 0.0367) and posterior (P = 0.0511) analyses, respectively. CONCLUSIONS: Within the limitations of this study, most of the population (64%) surveyed indicated the ISC as a therapeutic solution for the replacement of a single missing tooth, showing a higher WTP index in the anterior area. Among investigated socio-demographic variables, the importance assigned by the patient to oral care appeared to influence WTP values of the rehabilitation, regardless the location of the single gap in the mouth.

Early bond strength to low-pressure sandblasted zirconia: evaluation of a self-adhesive cement.

The debonding of a densely sintered zirconia prosthesis is a clinically reported, and undesirable event. A standardized, affordable adhesive cementation protocol for zirconia-based restorations is not yet available. The aim of this investigation was to assess the influence of several surface treatments on the initial shear bond strength of self-adhesive resin cement to densely sintered zirconia ceramic. Thirty densely sintered zirconia cylinders were divided into three groups (n = 10). Each of them received a different surface treatment: control (No_T), with the zirconia surface unconditioned; low pressure air abrasion (Sand_S) (50 µm, 1 bar); and standardized air abrasion (Sand_H) (50 µm, 2.8 bar). Three more surface-treated only specimens were addressed to scanning electron microscope (SEM) for qualitative observations. After specimen fabrication, self-adhesive cementceramic interface was analyzed using SBS (shear bond strength) test. Mean shear bond strengths (MPa) obtained for Sand_H and Sand_S were 16.24 ± 2.95 and 16.01 ± 2.68, respectively; no statistically significant difference (P = 0.8580) was found between sandblasted groups. Low-pressure air abrasion positively affected the initial self-adhesive cement adhesion to zirconia with respect to the No_T control group; however it did not prevent scratches and the formation of microcracks on the ceramic surfaces.