Porcelain Veneer Restorations Research Articles

Patient Satisfaction of Porcelain Veneer at the Odonto-Stomatology Hospital, Vietnam

Abstract Objective The aim of this study was to study the clinical characteristics and patient satisfaction of the porcelain veneer aesthetic restoration at the Central Odonto-Stomatology Hospital, Vietnam. Materials and Methods This is a cross-sectional descriptive study of 94 teeth in 12 patients with indications for glass-ceramic restorations at the Department of Prosthodontics at the Central Odonto-Stomatology Hospital during the period from July 2021 to December 2022. Porcelain veneer aesthetic restorations in patients were evaluated using FDI World Dental Federation clinical criteria for the evaluation of veneer restorations for the esthetic parameters, functional parameters, biological parameters, and reliability. The evaluation was done immediately after installation and after 3 months. Evaluation of aesthetics, function, biology, and satisfaction was done using a scale (Scale 1–5). Data were analyzed using SPSS 18 software and descriptive statistics were calculated. Results It showed that the achieved results were good in terms of good to very good shape (100%) and good to very good color (98.8%). Three months after installation, the veneer restorations were stable in shape and color. The restorations were aesthetically and functionally satisfactory with no signs of broken or detachment. Conclusion Porcelain veneer restorations helped to improve the tooth shape and color. The patients were satisfied with the veneer restorations.

Ceramic anterior veneer restorations in periodontally compromised patients: A retrospective study.

Successful periodontal therapy can lead to poor esthetic results, especially in the anterior region, for which there are treatment options such as direct composite or indirect veneer restorations. Until now, there are no data describing the long-term results of veneer restorations in periodontally treated patients. The aim of this retrospective study was to evaluate the outcome of anterior porcelain veneer restorations in periodontally compromised and noncompromised patients. Periodontally healthy and periodontally compromised patients, who had received anterior veneer restorations at least 5years ago, were invited to a follow-up examination. Groups were divided according to their periodontal diagnosis (periodontally healthy, stage I/II, stage III/IV). Tooth loss, veneer loss, biologic parameters, and complication rates were examined. Also, veneers were evaluated according to modified United States Public Health Service criteria. A total of 68 patients with 312 veneers were examined with a mean follow-up time of 8years. Veneered teeth in patients with periodontitis stage III/IV showed no difference regarding tooth-specific, overall, and functional veneer survival when compared to periodontally healthy patients (Kaplan-Meier analyses). In Cox regression analysis, follow-up time had an impact on complications and veneer loss, whereas periodontal diagnosis showed no significant influence on the survival of restorations. Comparative tests showed that patients with severe periodontitis at baseline have slightly lower veneer survival rates after 8years and slightly higher complication rates after 13years. Long-term results and complication rates of veneer restorations in periodontally compromised patients are comparable to periodontally healthy patients over a mean follow-up of 8years.

Marginal Fit of Porcelain Laminate Veneer Materials under Thermocycling Condition: An In-Vitro Study.

Objective: The purpose of this study was to evaluate the cervical marginal fit of porcelain laminate veneer (PLV) restorations made from two different types of CAD/CAM ceramic laminates: CEREC C PC and E.max (LD). Materials and Methods: This in-vitro experiment used a total of 32 human maxillary first premolars that were clean and free of any cracks or caries, extracted for orthodontic purposes. The samples were divided in a random way into two study groups: A and B (n = 16). Each sample was mounted on a dental surveyor and a silicon impression was made to create a silicone index for each tooth in both groups. Standardized preparation was carried out for all the samples by using preparation bur kit for the ceramic veneer system. Subsequently, digital impressions were made for all the samples by using Trios 3 shape intraoral camera (Sirona Dental Systems). The design of veneer restorations was made using Sirona inLab CAD SW 16.1 with CEREC inLab MC XL (Dentsply, Sirona Dental Systems, Bensheim, Germany). The veneer restorations were cemented using 3M RelyX veneer resin cement (3M ESPE, Seefeld, Germany) and the samples kept in distilled water for two weeks at 37 °C. All the specimens were subjected to thermocycling in a water bath with temperature varying between 5 °C and 55 °C for 500 cycles. The cervical marginal fit of veneers was evaluated by a digital microscope after sectioning the embedded teeth in acrylic resin. Results: The lowest mean of cervical marginal gap was recorded for Group A (91.59431 ± 1.626069) which was restored with CEREC CAD/CAM veneers, while the highest mean value of the gap was recorded for Group B (106.48863 ± 2.506684) which was restored with IPS E.max CAD. The t-test showed that the type of porcelain veneer restoration had a highly significant effect on the cervical marginal fit (p ≤ 0.01). Conclusions: CEREC CAD/CAM veneers showed smaller cervical marginal gaps, indicating a better fit compared to the IPS E.max CAD.

Interdisciplinary approach for complex esthetic periodontal or prosthodontic treatment: a case report

Patients with a complex periodontal/restorative esthetic condition can only be successfully treated with an interdisciplinary approach. This report presents case managed with varying levels of periodontal and prosthodontic coordination of care. A 48-year-old female patient with no medical conditions, presented chiefly to enhance her dental esthetics and eliminate the central diastema. There was also gingival asymmetry and altered passive eruption (APE). High frenal attachment was also noticed in relation the central diastema space. The depigmentation, gingivectomy, and gingivoplasy procedures were planned accordingly. After 3 months of periodontal healing, the patient returned for the final porcelain veneer restorations limiting to the upper anterior incisors. The treatment of the complex periodontal/prosthetic esthetic patient can be achieved with an interdisciplinary approach. Such a dental rehabilitation should be beginning by a comprehensive esthetic examination. Then an accurate diagnosis, prognosis evaluation, and treatment planning have to be identified. In addition, the utilization of an advanced surgical and restorative biomaterials will ensure the best result with patient satisfaction.

Expert consensus on porcelain veneer technology in oral esthetic restoration

In recent years, porcelain veneer restoration has been widely carried out in clinical practice. In order to standardize the clinical behavior, Chinese Society of Esthetic Dentistry organized experts in relevant fields to formulate an expert consensus on porcelain veneer technology in oral esthetic restoration. The consensus described in detail the material selection, clinical indications, tooth preparation requirements and bonding process of porcelain veneer restoration. It puts forward expert suggestions on how to obtain the strong and durable porcelain veneer restoration effect, prevent complications, and provide patients with comfortable diagnosis and treatment experience. At the same time, in order to provide reference for making successful porcelain veneer restoration in line with the connotation of oral esthetics, Chinese Society of Esthetic Dentistry put forward with its own characteristics the concept of taking esthetic design as the guidance, emphasizing the combination of local and overall esthetics, and carrying out multi-disciplinary porcelain veneer restoration.

Effect of light intensity, light-curing unit exposure time, and porcelain thickness of ips e.max press and vintage LD press on the hardness of resin cement

Background: Porcelain veneer restoration is the primary choice for indirect restoration, especially for anterior teeth, given its high esthetic properties and lower failure rate than resin composites. Glass-based ceramics such as IPS e.max Press and Vintage LD Press are a choice for veneer due to its superior physical properties. Resin cement is used to attach the veneer restoration to the teeth. The polymerization of resin cement used in veneer restoration affects the stability, mechanical properties, and resistance of the restoration. The composition and thickness of the porcelain material affect the light-curing unit to cured resin cement. Objectives: The aim of this study was to evaluate the influence of porcelain thickness, light intensity, and exposure time in the hardness of resin cement. Methods: Porcelain samples measuring 5 mm in diameter with three types of thicknesses of IPS e.max Press and Vintage LD Press were used in the study. Resin cement in a metal mold was placed under a porcelain sample before curing with a light-emitting diode (LED) intensity of 1300 or 1700 mW/cm2. The hardness test was then carried out on the bottom of the resin cement. Result: The highest hardness value was obtained from a Vintage LD Press with a thickness of 0.7 mm (cured at 1300 mW/cm2 for 20 s). A four-way ANOVA test showed significant differences for brands, thicknesses, and times of exposure (P

Effectiveness of Porcelain Veneer on Dental Restoration in Rats with Periodontitis

The purpose of this study is to explore the effectiveness of porcelain veneer technology on periodontitis in rats, so as to better guide clinical practice. Using 70 rats the periodontitis rat model was established. Porcelain veneer was used to repair the rat teeth. Follow-up evaluation of the curative effect was carried out at 2, 4, 6 and 8 weeks after operation, so as to gain a certain understanding of the treatment of periodontitis with porcelain veneer. The results showed that after porcelain veneer restoration, the teeth of periodontitis rats constructed by string ligation became wider, the space between teeth become smaller, the height of tooth bone decreased and the teeth were closely adhered to the gingiva. After operation, alveolar bone volume significantly increased (P<0.05). The follow-up results showed that the success rates of porcelain veneer were 100, 100, 97.5 and 95 % on the 2, 4, 6 and 8 week after operation. These results indicated that the ceramic veneer exerted a good restorative effect on rat teeth with periodontitis and has a high stability after operation. It is hence worth further investing future in clinical research

Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements.

This study evaluated the effects of ceramic veneer thicknesses on the polymerization of two different resin cements. A total of 80 ceramic veneer disks were fabricated by using a pressable ceramic material (e.max Press; Ivoclar Vivadent) from a Low Translucency (LT) ingot (A1 shade). These disks were divided into light-cured (LC; NX3 Nexus LC; Kerr) and dual-cured (DC; NX3 Nexus DC; Kerr) and each group was further divided into four subgroups, based on ceramic disk thickness (0.3, 0.6, 0.9, and 1.2 mm). The values of Vickers microhardness (MH) and degree of conversion (DOC) were obtained for each specimen after a 24-hour storage period. Association between ceramic thickness, resin cement type, and light intensity readings (mW/cm(2)) with respect to microhardness and degree of conversion was statistically evaluated by using analysis of variance (ANOVA). For the DOC values, there was no significant difference observed among the LC resin cement subgroups, except in the 1.2 mm subgroup; only the DOC value (14.0 ± 7.4%) of 1.2 mm DC resin cement had significantly difference from that value (28.9 ± 7.5%) of 1.2 mm LC resin cement (p < 0.05). For the MH values between LC and DC resin cement groups, there was statistically significant difference (p < 0.05); overall, the MH values of LC resin cement groups demonstrated higher values than DC resin cement groups. On the other hands, among the DC resin cement subgroups, the MH values of 1.2 mm DC subgroup was significantly lower than the 0.3 mm and 0.6 mm subgroups (p < 0.05). However, among the LC subgroups, there was no statistically significant difference among them (p > 0.05). The degree of conversion and hardness of the resin cement was unaffected with veneering thicknesses between 0.3 and 0.9 mm. However, the DC resin cement group resulted in a significantly lower DOC and MH values for the 1.2 mm subgroup. While clinically adequate polymerization of LC resin cement can be achieved with a maximum 1.2 mm of porcelain veneer restoration, the increase of curing time or light intensity is clinically needed for DC resin cements at the thickness of more than 0.9 mm.

Survival Rates for Porcelain Laminate Veneers with Special Reference to the Effect of Preparation in Dentin: A Literature Review

The porcelain laminate veneer is an elective restoration, often placed in the absence of disease for purely esthetic reasons. As such, it would appear desirable that the success rate of the technique was 100%. It is therefore the purpose of this paper to review the literature on porcelain laminate veneer survival by searching dental databases containing clinical trials of porcelain veneer restorations. References of selected trials were also screened to identify relevant studies. Each paper that was included was examined to ascertain if preparation into dentin affected survival. A total of 24 papers were included in the review. It was concluded that survival rates of porcelain laminate veneers are rarely 100%, and there is reasonable evidence indicating that a veneer preparation into dentin adversely affects survival. A review of the literature has indicated that porcelain laminate veneer survival is rarely 100%. Accordingly, patients should be made aware of this before embarking on this elective restorative technique. Clinicians should also be aware that the ideal preparation for porcelain veneers remains within enamel.

Comparison the Surface Roughness of Polishing And Glazed Ceramic With Glazed Zirconium Based Ceramic

Porcelain veneer restoration often require modification at laboratory and chair side prior to cementation .Common adjust - ments include contour, occlusion , color correction , and special characterization masking of imperfections and final glazing. The purpose of this study to compare surface roughness of polished, glazed porcelain with ceramic based zirconium. Thirty samples {Twenty porcelain specimens resembling flat-back facing (Metal porcelain buttons) of vita ceramic and ten specimens of ceramic based zirconium } were fabricated according to the manufacturer’s Instructions.(prepared with dimension of (10mm) in diameter and (2mm) in thickness). The specimens were divided into three groups according to the type of surface treatment tested .Each group consisted of ten specimens and the groups were distributed as follows:- - Group A: Polished unglazed porcelain with Rubber wheel. - Group B: Glazed ceramic based Metal. - Group C: Glazed ceramic based with zirconium. The surface roughness evaluation of the specimens was carried out by a surface roughness analyzer device (profilometer). Statistical analysis of data using (ANOVA- one way test) indicated high significant differences among the tested groups. The highest roughness value was scored by group A (porcelain polished with rubber wheel ) followed by group B ( glazed ceramic based Metal.) then group C ( glazed ceramic based zirconium). - Group (A) showed statistical significance in comparism to group (B). - Group (A) showed high statistical significance in comparism to group(C) -Group (B) showed statistical significance in comparism to group(C). According to the conditions under which this study was carried out, it may be concluded that mechanical finishing, polishing procedures were not able to provided a surface as smooth as the glazed surface for the tested porcelain.

Experimental–Numerical Investigation on the Biomimetic Recovery of Natural Tooth Structural Response after Porcelain Veneer Restoration

Abstract: This study analyzes the effect of porcelain veneer restoration on the structural response of a maxillary incisor. Tooth deformation is evaluated, prior to and after restoration, by the synergic use of Phase‐Shifting Electronic Speckle Pattern Interferometry (PS‐ESPI) and 3D finite element (FE) analyses. The intact maxillary incisor and the porcelain veneer restored tooth are subject to flexural load. Displacement fields are measured with Phase‐Shifting Electronic Speckle Pattern Interferometry. Experimental tests are simulated with 3D FE analyses tuning materials parameters via an optimisation‐based inverse procedure. ESPI measurements indicate that the restoration design under study produced deformations very similar to those of the intact tooth under load. FE results show sharp changes in displacement and stress 1 mm above the cement–enamel junction on the facial side of the restored tooth. Severe stress concentration (about 50% increase with respect to natural tooth) appears at the interface between veneer restoration and intact enamel and dentine tissues. This confirms the hypothesis that veneer restorations can amplify the effect of occlusal loading on the loss of dental hard tissue in the tooth cervical region.

Comparison of color and translucency between resin and try-in paste with same number

To test and compare the color and translucency between the mono-component light-cure adhesive resin and try-in paste with same number for porcelain veneer restorations, and evaluate the consistency of the materials. Variolink Veneer and Relyx Veneer were involved in the study. The adhesive resins and try-in pastes were added into a model of diameter of 10 mm and thick of 2 mm with white background and covered with filtered cover glass, and then the resins was cured with light. The color (L(*), a(*), b(*)) of these samples was test and ΔE was also calculated to evaluate the color consistency of samples. The resins and try-in pastes were made into a thin layer of 0.15 mm, and their translucency was tested under the light from 380 µm to 780 µm. Average translucency was calculated. Tukey t-test for multiple comparisons was used to analysis the differences of ΔE. Paired t-test was used to analysis the differences of translucency of them. Tukey's t-test shows that the evaluation of ΔE of TR (1.11 ± 0.18) was a; those of LV-1 (6.38 ± 0.45), LV-2 (5.94 ± 0.19), A1 (7.54 ± 0.20), WO (4.24 ± 1.14) were b; those of HV + 2 (10.90 ± 0.41), HV + 1 (11.48 ± 0.17), LV-3 (10.69 ± 0.13), B0.5 (13.26 ± 0.21) were c; and those of HV + 3 (21.94 ± 0.21), MV0 (29.78 ± 0.14), A3 (32.67 ± 0.19) were d (a, b, c, d meaned that the consistency of resin and try-in paste became lower and lower). There were significant differences between resin and tray-in paste in 7 colors (A1, TR, HV + 3, HV + 2, HV + 1, LV-2, LV-3) of 12 colors (P < 0.01). The consistency of color and translucency between most adhesive resin and try-in paste with same number is low. This kind of materials should be used with caution in demanding cases.

A Variety of Patient Factors may Influence Porcelain Veneer Survival Over a 10-Year Period

Clinical records were reviewed for more than 80,000 different patients from the General Dental Services (GDS) in England and Wales. A total of 2562 porcelain veneer restorations were placed in 1177 adult patients (> or =18 years old, 35% male and 65% female) over a period of 11 years (January, 1991, to March, 2002). A number of factors were considered potentially capable of impacting the need for reintervention on teeth restored with porcelain veneers. These included a number of patient factors such as gender, age, and dental utilization practices. Other factors analyzed included the tooth position receiving veneers, dentists' qualifications, and where and when the veneer was placed (eg, month and geographic location). The main outcome was survival over 10 years between initial placement and the first date of intervention for each tooth treated with a porcelain veneer. Information was abstracted from clinical records to create an analytical dataset of porcelain veneers, with their dates of placement and their dates, if any, of reintervention. This dataset was analyzed using a modified Kaplan-Meier statistic and a Cox-regression model. Factors that were found to influence the survival of porcelain veneers included the following: gender, with veneers placed in male patients surviving for less time than those placed for female patients (P = .01); patient age, with poorer survival of porcelain veneers in older (60 years or older) patients (P = .003); changing dentist, with teeth of patients who change dentist surviving for shorter periods of time to reintervention than for those patients who continue in the care of the same dentist (P < .001); patient's treatment need, with patients whose gross annual fees on all dental treatment are higher having teeth with less time to reintervention after receiving veneers than those patients with lower annual fees (P < .001); patient paying status, with patients who are exempt from charges also having veneered teeth with shorter time to reintervention (P <.001). Nevertheless, the factors associated with tooth position or mouth quadrant and with the dentist (gender, age, years since graduation, and country of qualification) did not influence the survival rate. Although dentist factors do not appear to play a part, a variety of patient factors have been found to influence veneer survival to reintervention. Overall, 53% of porcelain veneers in the study survived without reintervention at 10 years.

An investigation into the effect of try-in pastes, uncured and cured resin cements on the overall color of ceramic veneer restorations: An in vitro study

Objectives The aim of this study was to assess how different shades of try-in pastes, uncured and cured resin cements influence the overall color of porcelain veneer restorations. Methods Porcelain veneers of shade Vita 1M1 VM7 and 1 mm thick were applied to bovine teeth using three shades of resin cement and their try-in paste produced by three manufacturers. Analysis of variance was carried out on the color difference values (Δ E*) between the Aquagel and both the try-in paste and cured resins. An assessment of the clinical significance of Δ E* between the try-in paste and the cured resin and also between the uncured and cured resin was made. Results There were statistically significant differences in veneers’ colors when using different shades of both Calibra and Nexus resin cements ( p < 0.05). Also, statistically significant differences were noticed when using different shades of both Rely-X and Nexus try-in pastes ( p < 0.05). Color differences produced between the try-in pastes and the corresponding shades of cured resin cements ranged from Δ E* 1.05 to 3.34. The color differences between uncured and cured resins of the same shade ranged from Δ E* 0.78 to 1.41. Conclusions Different colored try-in pastes and resin cements produced color changes which are clinically useful in changing the color of veneer restorations and therefore aid color matching to adjacent dentition. Clinically significant differences were found between try-in pastes and the cured resin of the same shade, however, there were relatively small changes measured between uncured and cured resins. The color match achieved by the try-in paste has to be treated with caution and further assessment of the restoration made with the resin in place before curing is recommended.

Fracture Resistance and Deflection of Pulpless Anterior Teeth Restored with Composite or Porcelain Veneers

Introduction The aim of this in vitro study was to evaluate the influence that resin composite and porcelain veneer restorations, associated or not to fiber post placement, have on fracture resistance and deflection of pulpless anterior teeth. Methods One hundred twenty freshly extracted human maxillary central incisors were selected. Teeth were randomly divided into 7 experimental groups (veneer preparation/resin composite veneer placement/endodontic therapy and resin composite veneer placement/endodontic therapy, fiber post and resin composite veneer placement/porcelain veneer placement/endodontic therapy and porcelain veneer placement/endodontic therapy, fiber post and porcelain veneer placement) and a control group (n = 15). Specimens were loaded to fracture recording crown deflection, and data were statistically analyzed. Results Veneer preparations did not significantly influence fracture resistance of incisors. On the contrary, veneer preparation significantly increased specimen deflection values. Fiber posts seemed to significantly increase mean maximum load values for endodontically treated teeth restored with either composite or porcelain veneers. Conclusions A fiber post restoration can be suggested when endodontic treatment is associated with veneer restoration. Veneer restorations seem to be an optimal choice also for endodontically treated teeth.

A BITTERSWEET SILVER ANNIVERSARY FOR THE BONDED PORCELAIN VENEER RESTORATION

A BITTERSWEET SILVER ANNIVERSARY FOR THE BONDED PORCELAIN VENEER RESTORATION

Ten-year outcome of porcelain laminate veneers placed within the general dental services in England and Wales

Aim It is the aim of this paper to consider the factors associated with the need for re-intervention on teeth restored with porcelain veneers. Methods A data set was established consisting of adult patients (18 years or older) whose restoration records contained the placement of one or more porcelain laminate veneers. For each tooth treated with a porcelain veneer, the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the extended data set, was obtained. Thus a data set was created of porcelain veneers which have been placed, with their dates of placement and their dates, if any, of re-intervention. Results Data for over 80,000 different adult patients were analysed, of whom 46% were male and 54% female. A total of 2562 porcelain veneer restoration occasions in 1177 patients were obtained from the data over a period of 11 years. Factors which were found to influence the survival of porcelain veneers include patient gender, patient age, changing dentist, patient's treatment need, patient charge-paying status and geographical area. Conclusions While dentist factors do not appear to play a part, a variety of patient factors have been found to influence veneer survival to re-intervention. Overall, 53% of porcelain veneers in the study survived without re-intervention at 10 years.

The Myth of Instant Orthodontics: An Ethical Quandary

There is a clinical trend of using porcelain veneer restorations (PVRs) for the correction of malaligned anterior teeth. Use of PVRs for this purpose raises clinical and ethical dilemmas.A literature review of four different topics (PVR preparation, enamel thickness of anterior teeth, dentinal bonding adhesive effectiveness and PVR long-term success) was conducted to determine the optimal preparation for a successful PVR. The amount of tooth malalignment that may be corrected with a PVR without adversely affecting its success was calculated.The optimal preparation for a successful PVR may have dentin exposed in the body of the preparation. However, most of the preparation must be in enamel, and all the margins must end in enamel. The strength of a dentin bond varies greatly owing to a multistep, technique-sensitive cementation process and is weaker than an enamel bond. It is not possible to correct atypical gingival esthetics (uneven gingival margins, uneven papillae, short papillae and bulbous gingivae) resulting from malaligned teeth through use of PVRs.andAligning a healthy tooth with a PVR is not a conservative procedure and more conservative treatment options (such as orthodontics, bleaching, direct bonding and enamelplasty) should be offered to the patient. In addition, the inability to restoratively improve gingival relationships with PVRs may result in achieving less-than-optimal esthetics. A clinician should present only treatment options that involve predictable, conservative restorations or that preserve healthy tooth structure. Aligning teeth with PVRs may create ethical dilemmas that can be resolved with the help of the American Dental Association Principles of Ethics and Code of Professional Conduct.

Microleakage of porcelain veneer restorations bonded to enamel and dentin with a new self-adhesive resin-based dental cement

Cementation technique of bonded ceramic restorations is a time-consuming and technique-sensitive procedure critical to long-term success. Objective Evaluate the performance of a self-adhesive, modified-resin dental cement (Rely-X UniCem, 3M-ESPE) for the cementation of ceramic veneer restorations without previous conditioning of the tooth surface, and in combination with a one-bottle adhesive and a self-etching adhesive. Methods Thirty-six premolars received a veneer preparation that extended into dentin. Leucite-reinforced pressed glass ceramic (Empress 1) veneers were cemented following manufacturers’ instructions, according to the following treatment groups ( n = 9): (1) Variolink–Excite Ivoclar–Vivadent (V + E control), (2) Unicem + Single Bond 3M-ESPE (U + SB), (3) Unicem + Adper Prompt L-Pop 3M-ESPE (U + AP), (4) Unicem 3M-ESPE (U). After 24 h storage at 37 °C, teeth were thermocycled (2000 cycles) at 5 and 55 °C, immersed in ammoniacal silver nitrate for 24 h, placed in a developer solution overnight and sectioned using a slow-speed saw. Three 1 mm longitudinal sections were obtained from each tooth and evaluated for leakage with a microscope (1× to 4×). Imaging software was used to measure stain penetration along the dentin and enamel surfaces. Results ANOVA with SNK ( α = 0.05) revealed that on dentin, U had significantly less leakage than U + SB and U + AP, but no different than V + E; on enamel U had leakage values that were significantly greater than the groups with adhesives. Significance The self-adhesive cement U gave low leakage on dentin that was comparable to the cement that employed an adhesive for sealing dentin, whereas this cement benefits from use of an adhesive when cementing to enamel.

Dentin exposure in tooth preparations for porcelain veneers: A pilot study

The various clinical techniques available for even reduction of a tooth surface to receive a porcelain veneer restoration do not produce a consistently even conservative reduction. In addition, it is not known which technique is most conservative of enamel. The purpose of this pilot study was to assess the effectiveness of 3 clinical techniques, namely, dimple, depth groove, and freehand, in producing an intraenamel preparation. The relation between overpreparation beyond the commonly accepted depth of preparation of 0.5 mm and dentin exposure was also examined. A single operator prepared 3 groups of 5 extracted maxillary central incisors to a depth of 0.5 mm using dimple, depth-groove, and freehand methods of tooth preparation. The prepared teeth were scanned using an x-ray microtomography scanner. The reconstructed images were studied using software that provided a volume-rendering routine so that, by choosing suitable x-ray linear attenuation coefficient thresholds, enamel (2.78 cm(-1) at 40 keV) and dentin (1.63 cm(-1) at 40 keV) surfaces could be viewed. The percentage area of enamel conserved was analyzed from these images. Coordinate metrology was used to produce color-coded images depicting the depth of preparation. The Kruskal-Wallis test was used to determine the statistical significance (alpha=.05) in the difference between the mean percentage area of enamel conserved in the 3 technique groups. The coordinate metrology and x-ray microtomography images were visually compared to study the correlation between overpreparation and dentin exposure. The Kruskal-Wallis test did not demonstrate significant difference (P=.07) between the 3 techniques in conserving enamel. However, the dimple technique showed a greater trend to retaining a larger mean percentage area of enamel (77.5% +/- 14.2) compared to depth-groove (50.1% +/- 17.5) and freehand (76.8% +/- 24.4) techniques. Preparation depth in the range of 0.4 to 0.6 mm was largely seen to be intraenamel, except in the cervical region. Within the limitations of this pilot study, the 3 different techniques tested did not differ significantly in conserving enamel.