Implant Stability after Graftless Motor-Driven Crestal Sinus Elevation: A Cohort Study.

Graftless motor-driven crestal sinus elevation may be a preferable alternative to conventional methods due to the reduction of post-surgical complications and lower cost. This prospective cohort study evaluated the stability of implants installed using this technique. Twenty-nine Straumann BLT implants in 29 different patients were included in the sample. Average implant stability quotients (ISQ) were measured immediately after surgery (Mean 73.5 ± 9.2) and after a period of healing (Mean 77.1 ± 4.5) using resonance frequency analysis (RFA). There was a significant increase in implant stability after healing (p = .035). The healing duration did not significantly influence how implant stability increased (p =.373). The mean ISQ after healing was significantly higher than the clinically acceptable stability value of 65 ISQ (p <.001). Implant length and width were not significantly correlated with ISQ increase (p =.764 and p =.085, respectively). In addition, there were no significant differences in average ISQ values measured immediately post-surgery (at baseline) or after healing between implants with and without registered perforations during surgery (p =.118 and p =.366, respectively). The post-healing stability of four implants that did not achieve primary stability was not significantly less stable after the healing period than those that had achieved primary stability (p =.086). Moreover, the level of insertion torque significantly impacted implant stability immediately post-surgery (p < .001), but the ISQ values measured after healing were not significantly different based on the initial insertion torque values (p = .131). This study suggests that implants installed using graftless motor-driven crestal sinus elevation may achieve clinically acceptable stability as measured by RFA.

In Vitro Evaluation of Candida albicans Adhesion and Related Surface Properties of CAD/CAM Denture Base Resins.

OBJECTIVE: The aim of this study was to evaluate the surface roughness, contact angle, and adhesion of Candida albicans to computer-aided designing/computer-aided manufacturing (CAD/CAM) and heat-polymerized (HP) denture base materials. MATERIALS AND METHODS: Specimens were allocated to six groups based on the composition of studied denture base materials, HP acrylic resin, milled resins (AvaDent and IvoCad), and 3D-printed resins (ASIGA, FormLabs, and NextDent). Ten specimens per group were used for each test (n = 10/test). Surface roughness and contact angles were analyzed using profilometer and goniometer, respectively. Adhesion of C. albicans was counted using colony-forming unit (CFU/mL). Means and standard deviations were calculated, and then one-way analysis of variance (ANOVA), followed by Tukey's post hoc test. Correlation of Candida adhesion and surface parameters was determined by using Pearson's correlation analysis. RESULTS: No statistically significant difference was noted in surface roughness between HP, milled, and 3D-printed denture base resins except NextDent, which showed significantly higher roughness in comparison to all other resins (p = 0.001). In terms of contact angle, milled resins had the lowest value, followed by HP, ASIGA, and FormLabs, whereas NextDent showed the highest contact angle (p = 0.001). C. albicans adhesion showed no significant difference between all denture base resins. A positive and significant correlation was found between C. albicans adhesion and contact angle (p = 0.003), while no correlation was reported between C. albicans adhesion and surface roughness (p = 0.523). CONCLUSION: Adhesion of C. albicans was similar in all tested specimens. Surface roughness showed no significant difference between all groups except NextDent, which had the highest value. Milled denture base resins had the lowest contact angle among all groups.

Influence of Denture Cleansers on the Retention Loss of Attachment Systems Retained Implant Overdenture.

Background: This study aimed to evaluate the effects of different denture cleansing solutions (DCSs) on the retention of Locator and Locator R-Tx attachment systems of implant retained overdentures (IRO). Methods: Two part acrylic resin blocks were fabricated, upper part contained metal housing and plastic inserts and lower part contained implant analogs and abutments. Eighty pink plastic inserts (40/attachment, 10/solution) were immersed in Corega, Fittydent, sodium hypochlorite, and water for a time simulating upto 1-year of clinical usage. Acrylic blocks were held on a universal testing machine for a pull-out test to record the dislodgement force. Measurements were conducted after 6 months (T1) and 12 months (T2). One-way ANOVA followed by Tukey's HSD test was used to analyze the results (α = 0.05). Results: For both attachments, retention significantly decreased after immersion in different solutions at T2 (P < 0.001). Locator R-Tx attachment in NaOCl showed a significant decrease in retention compared with other solutions at T1. At T2, there was a significant decrease in retention for all DCS compared with water (P < 0.001). Locator R-TX showed higher retention values per solution compared to Locator attachment (P < 0.001). In terms of retention loss %, NaOCl recorded the highest (61.87%) loss, followed by Corega (55.54%) and Fittydent (43.13%), whereas water demonstrated the best retention (16.13%) in both groups. Conclusion: Locator R-TX has better retention with different DCS immersion. The loss of retention varied with different types of DCS and NaOCl recorded the highest retention loss. Therefore, denture cleanser selection must be guided by the type of IRO attachment.

Flexural Properties and Hardness of CAD-CAM Denture Base Materials.

PURPOSE: To compare flexural strength, elastic modulus, and surface hardness of computer aided design and computer aided manufacturing CAD-CAM milled, 3D-printed, and heat-polymerized denture base resins. MATERIALS AND METHODS: A total of 120 specimens were fabricated from heat-polymerized acrylic resin (HP), milled resin (Avadent and IvoCad), and 3D-printed resin (ASIGA, FormLabs, and NextDent). The specimens were divided into 6 groups according to the type of denture base material (n = 20/material) (10/flexural properties and 10/hardness). Flexural strength and elastic modulus of the specimens were evaluated by 3-point bending test and surface hardness by Vickers hardness test. To test flexural properties, the specimens were fabricated according to ISO 20795-1:2013 standards (64 × 10 × 3.3 ± 0.2 mm). The dimensions for hardness test were 15 × 10 × 2.5 ± 0.2 mm. Scanning electron microscope was used to evaluate the surface morphology of the fractured specimens. The means and standard deviations were calculated, followed by one-way ANOVA and Tukey post-hoc test (α = 0.05). RESULTS: Milled resins showed significantly higher values for flexural strength, elastic modulus, and surface hardness, followed by HP and then 3D-printed resins (p < 0.001). Within milled groups, flexural strength of AvaDent was significantly higher than IvoCad (p < 0.001), while elastic modulus and hardness didn't show significant difference. Within 3D-printed resins, ASIGA showed the highest flexural strength and elastic modulus, insignificantly with FormLabs (p = 0.595) and significantly with NextDent (p = 0.008). ASIGA also showed significantly the highest hardness among the 3D-printed groups. No significant difference was found between FormLabs and NextDent in flexural strength (p = 0.357), elastic modulus (p = 1.00), or surface hardness (p = 0.987). CONCLUSION: CAD-CAM milled resins had greater flexural properties and hardness compared to heat-polymerized acrylic resin and 3D-printed resins. Although 3D-printed samples showed the lowest values of tested properties, the flexural strength and modulus were above clinically acceptable values.

Influence of ZrO2 Nanoparticle Addition on the Optical Properties of Denture Base Materials Fabricated Using Additive Technologies.

This study investigated the translucency of 3D-printed denture base resins modified with zirconium dioxide nanoparticles (ZrO2NPs) under thermal cycling. A total of 110 specimens were fabricated and divided into 3 groups according to the materials, i.e., heat-polymerized resin, and 3D-printed resins (NextDent, and ASIGA). The 3D-printed resins were modified with 0, 0.5, 1, 3, and 5 wt.% of ZrO2NPs. All the specimens were subjected to 5000 thermal cycles. The translucency was measured using a spectrophotometer. The results showed that the heat-polymerized resin had considerably higher translucency than the 3D-printed resins. Compared to the unmodified group, the translucency decreased significantly after adding 5% ZrO2NPs to NextDent and 3% ZrO2NPs to ASIGA resins. The highest translucency was achieved for NextDent by adding 0.5% ZrO2NPs and for ASIGA without any ZrO2NPs. It was found that the average concentration level in ASIGA was significantly higher than that in NextDent. These findings revealed that 3D-printed resins have lower translucency than heat-polymerized acrylic resin, and adding ZrO2NPs at low concentrations did not affect the translucency of the 3D-printed resins. Therefore, in terms of translucency, 3D-printed nanocomposite denture base resins could be considered for clinical applications when ZrO2NPs are added at low concentrations.

Comparative Evaluation of Surface Roughness and Hardness of 3D Printed Resins.

The effect of printing parameters on the surface characteristics of three-dimensional (3D)-printed denture base resins (DBRs) is neglected. Therefore, this study investigated the effect of printing orientation and post-curing time on the surface roughness and hardness. One conventional heat-polymerized (HP) resin and two 3D-printing resins (NextDent (ND) and ASIGA (AS)) were used to fabricate a total of 250-disc (10 × 2.5 mm) specimens. ND and AS specimens were printed with different orientations (0-, 45-, and 90-degree) and each orientation group was subjected to four post-curing times (30, 60, 90, 120 min). Printed specimens were thermo-cycled (10,000 cycles) followed by the measuring of surface roughness (Profilometer (Ra)) and hardness (a Vickers hardness (VH)). ANOVA and post hoc tests were used for data analysis (α = 0.05) at significant levels. AS and ND showed no significant changes in Ra when compared with HP (p ˃ 0.05), except the 45-degree orientation (AS/90 min and AS/120 min) significantly increased surface roughness (p ˂ 0.001). There was no significant difference in Ra with different orientations and post-curing time for both materials AS and ND (p ˃ 0.05). Compared with HP, 3D-printed DBRs showed low VH values (p ˂ 0.001). For AS, 90-degree orientation showed a significant decrease in VH at 60, 90, and 120 min when compared with 0- and 45-degree orientation (p ˂ 0.001), while ND showed no significant difference in VH with different printing orientations (p ˃ 0.05). The VH of AS and ND improved when increasing post-curing time to 120 min (p ˂ 0.001), and the printing orientations and post-curing time did not affect the Ra of 3D-printed DBRs.

Clinical Evaluation of Short Tuberosity Implants among Type 2 Diabetic and Non-Diabetic Patients: A 5 Year Follow-Up.

Aim: To assess clinical and radiographic parameters including bleeding on probing (BoP); probing depth (PD), plaque index (PI) and crestal bone loss (CBL) around short tuberosity implants (STI) supporting fixed partial dentures in patients with Type 2 diabetes mellitus (T2DM) and non-diabetics. Material and Methods: Participants with T2DM and without T2DM with at least one STI (6 mm) posteriorly restored with a fixed partial denture splinting premolar implant were included. A questionnaire collected demographic details including gender, age, duration of diabetes, habits of brushing, the total number of dental implants and location, implant loading after placement, restoration type, and family history of DM. Clinical and radiographic assessment of peri-implant parameters, i.e., bleeding on probing (BoP), probing depth (PD), plaque index (PI), and crestal bone loss (CBL) was performed. The restorative success of STI was determined by no sensation of the foreign body, lack of pain and dysesthesia, lack of infection, no radiolucency around the implant, and no mobility. The Kruskal-Wallis test was used for statistical analysis. A p-value of less than 0.05 was considered statistically significant. Results: Twenty-five T2DM (19 males and 6 females) and 25 non-diabetic (18 males and 7 females) participants were included. The number of STIs in T2DM was 41, whereas in non-diabetic it was 38. At 1 year follow-up, mean PI% in T2DM participants was 18.9% (19.2-21.4%) and in non-diabetics it was 17.6% (16.3-18.5%). The mean PD was recorded in diabetics (1.3 ± 5.0 mm) and non-diabetics (1.1 ± 3.2 mm). The BoP value in diabetics was 44.9% (39.8-46.4%) and 28.2% in non-diabetics (17.2-24.6%). At 5 years of follow-up, the mean PI% range in T2DM participants was 26.18% (25.4-29.1%) and 24.42% in non-diabetic (20.1-25.5%). The mean PD in millimeters around STI in T2DM was observed to be 2.3 ± 4.8 mm and 1.4 ± 3.4 mm in non-diabetics. In addition, BoP in diabetic participants was 39.54% (27.7-42.1%) and 24.42% in non-diabetics (20.1-25.5%). A total of six STIs failed, i.e., two in the non-diabetic and four in the T2DM group. Conclusions: Patients with T2DM have poor periodontal (BoP, PD, CBL) and restorative peri-implant parameters around STIs when compared to healthy (non-diabetic) participants at five years of follow-up. For long-term stability, glycemic control is pivotal along with following good plaque control.

Impact of Polymerization Technique and ZrO2 Nanoparticle Addition on the Fracture Load of Interim Implant-Supported Fixed Cantilevered Prostheses in Comparison to CAD/CAM Material.

ZrO2 nanoparticles (ZNPs) have excellent physical properties. This study investigated the fracture load of implant-supported, fixed cantilevered prosthesis materials, reinforced with ZNPs and various polymerization techniques, compared with conventional and CAD/CAM materials. Sixty specimens were made from two CAD/CAM; milled (MIL) (Ceramill TEMP); and 3D-printed (NextDent Denture 3D+). Conventional heat-polymerized acrylic resin was used to fabricate the other specimens, which were grouped according to their polymerization technique: conventionally (HP) and autoclave-polymerized (AP); conventionally cured and reinforced with 5 wt% ZNPs (HPZNP); and autoclave reinforced with 5 wt% ZNPs (APZNP). The specimens were thermocycled (5000 cycles/30 s dwell time). Each specimen was subjected to static vertical loading (1 mm/min) using a universal Instron testing machine until fracture. Scanning electron microscopy was used for fracture surface analyses. The ANOVA showed significant fracture load differences between all the tested groups (p = 0.001). The Tukey post hoc tests indicated a significant difference in fracture load between all tested groups (p ˂ 0.001) except HP vs. HPZNP and AP vs. MIL. APZNP had the lowest mean fracture load value (380.7 ± 52.8 N), while MIL had the highest (926.6 ± 82.8 N). The CAD/CAM materials exhibited the highest fracture load values, indicating that they could be used in long-term interim prostheses. Autoclave polymerization improved fracture load performance, whereas ZrO2 nanoparticles decreased the fracture load performance of cantilevered prostheses.

Microleakage and Bacterial Adhesion with Three Restorative Materials Used to Seal Screw-access Channels of Implant Abutments: An In vitro Study.

BACKGROUND: Proper sealing of screw-access channels against microbial microleakage is advisable for the long-term success of screw-retained implant prosthesis. OBJECTIVE: This study aimed to compare the bacterial adhesion and microleakage with three restorative materials, namely, composite resin, acrylic resin and bis-acryl, that are used to cover the access channels of screw-retained implant prostheses, using polytetrafluoroethylene tape as a spacer material. MATERIALS AND METHODS: In this in vitro study, 18 titanium straight abutments (Hex-lock® Zimmer) were torqued into implant analogs, which were then subdivided into three groups. The samples of each group were filled with polytetrafluoroethylene tape and sealed with the three restorative materials (Group A: composite resin; Group B: acrylic resin; Group C: bis-acryl). Measurements of surface bacterial adhesion and internal microleakage were then recorded. The results were statistically analyzed using Kruskal-Wallis and Chi-square tests. RESULTS: No significant difference was found between the investigated materials in terms of their sealing effectiveness against microbial microleakage (P = 0.06). Regarding bacterial adhesion, composite resin showed the highest number of surface adhesion, but there was no significant difference between the three materials (P = 0.081). CONCLUSION: The results of this study suggest that composite resin, acrylic resin and bis-acryl materials could be used alternatively in sealing the implant access channel owing to no significant differences in terms of microleakage and bacterial adhesion.

Clinical Applications of Intraoral Scanning in Removable Prosthodontics: A Literature Review.

PURPOSE: This review aimed to identify the reported intraoral scanning applications in fabricating different types of removable prostheses in the field of prosthodontics. METHODS: A comprehensive electronic search was performed using the PubMed and MEDLINE databases. This review included in vitro studies and clinical reports published between January 2013 and March 2021. The main keywords were as follows: intraoral scanning, digital impression, computerized digital impression, removable prosthesis, chairside computer-aided design/computer-assisted manufacturing, digital complete denture, digital immediate complete denture, digital interim complete denture, digital removable partial denture, digital removable overdenture, digital obturator, digital occlusal splints, and digital maxillofacial prostheses. RESULTS: In total, 33 papers (22 clinical reports, 8 papers focused on dental techniques, and 3 clinical studies) were included in the final analysis. CONCLUSIONS: The efficiency of using intraoral scanning in the field of removable prosthodontics was documented. However, there is a need for more clinical studies to identify intraoral scanning-usage protocols and to yield reliable and valid data.

Application of Three-dimensional (3D) Tumor Cell Culture Systems and Mechanism of Drug Resistance.

The in-vitro experimental model for the development of cancer therapeutics has always been challenging. Recently, the scientific revolution has improved cell culturing techniques by applying three dimensional (3D) culture system, which provides a similar physiologically relevant in-vivo model for studying various diseases including cancer. In particular, cancer cells exhibiting in-vivo behavior in a model of 3D cell culture is a more accurate cell culture model to test the effectiveness of anticancer drugs or characterization of cancer cells in comparison with two dimensional (2D) monolayer. This study underpins various factors that cause resistance to anticancer drugs in forms of spheroids in 3D in-vitro cell culture and also outlines key challenges and possible solutions for the future development of these systems.

Management of Failing Dental Implants following Orofacial Trauma: A Case Report.

Dental implant failure can be caused by several biomechanical and biological factors. Management of failed multiple adjacent dental implants can be challenging, as the amount of bone loss around these implants is often high. This necessitates the need to restore the supporting bone and replace the failed implants with new implants in optimal positions and with a favorable dental prosthetic option. This report describes a case of a 27-year-old female who presented with failed multiple adjacent maxillary dental implants following orofacial trauma and with a significant amount of supporting bone loss. The patient was managed by implants removal, bone grafting and implant-supported fixed hybrid prosthesis, which resulted in a positive outcome, despite several challenges.

Multidisciplinary approach with predictable esthetics: A case report.

This case report explains an effective multidisciplinary approach used to improve the function, biology, and esthetic of a patient presented with an excessive gingival display, a spacing between anterior teeth, small size anterior teeth in maxilla and mandible. Also, unrestorable molars were noted with multiple carious lesions. The treatment combined crown lengthening, prosthetic dentistry using lithium disilicate crowns and minimally invasive implants placement approach.

A Novel Extended Range Attachment System to Retain Implant Overdentures: A Clinical Report.

Various attachment systems have been used to facilitate the retention, stability, and support of overdentures. The low profile design, pivoting technology, and durability of the Locator attachment made it one of the commonly used tissue-supported implant-retained overdentures. It has been successfully used to retain overdentures as well as partial dentures. This article describes the uses of the new Locator R-Tx abutment and illustrates both the direct and indirect techniques used to process the denture attachment housing into the prosthesis to retain overdentures and partial dentures.

Effect of Nanodiamond Addition on Flexural Strength, Impact Strength, and Surface Roughness of PMMA Denture Base.

PURPOSE: To assess the effect of addition of different concentrations of nanodiamonds (NDs) on flexural strength, impact strength, and surface roughness of heat-polymerized acrylic resin. MATERIALS AND METHODS: 120 specimens were fabricated from heat-polymerized acrylic resin. They were divided into a control group of pure polymethylmethacrylate (PMMA; Major.Base.20) and three tested groups (PMMA-ND) with 0.5%wt, 1%wt, and 1.5%wt of added ND to PMMA. Flexural strength was determined using the three-point bending test. Impact strength was recorded by using a Charpy type impact test. Surface roughness test was performed using a Contour GT machine. One-way ANOVA and Tukey's post-hoc analysis (p ≤ 0.05) were used for statistical analysis. RESULTS: Acrylic resin reinforced with 0.5% ND displayed significantly higher flexural strength than the unreinforced heat-polymerized specimens, acrylic resin reinforced with 1% ND and the 1.5% ND (p < 0.0001). The impact strength of unreinforced heat-polymerized specimens was significantly higher than all nano-composite materials (p < 0.0001) with no significant difference between 1% ND and the 1.5% ND (p > 0.05). The addition of 0.5% ND and 1% ND significantly decreased the surface roughness in comparison to both control and the 1.5% ND groups (p < 0.0001) while no significant differences between 0.5% ND and 1% ND (p > 0.05) were reported. Nano-composite material (0.5% ND) showed significantly lower surface roughness when compared to other specimens. CONCLUSIONS: The addition of NDs to acrylic denture base improved the flexural strength and surface roughness at low concentrations (0.5%), while the impact strength was decreased with ND addition.

Effects of denture adhesive on the retention of milled and heat-activated maxillary denture bases: A clinical study.

STATEMENT OF PROBLEM: Clinical studies have identified advantages of digital complete denture technology including patient satisfaction, improved mastication, increased retention, and technique efficiency. However, studies that focus on the effect of denture adhesive on the retention of milled and heat-activated denture bases are lacking. PURPOSE: The purpose of this clinical study was to evaluate the effectiveness of denture adhesive on the retention of milled and heat-activated denture bases. MATERIAL AND METHODS: Twenty participants with complete maxillary edentulism were selected for this study (11 men and 9 women). Definitive impressions were obtained and scanned (iSeries impression scanner; Dental Wings). Digital data were sent to Global Dental Science for the fabrication of computer-aided design and computer-aided manufacturing (CAD-CAM) milled denture bases (MB condition). The physical impressions were poured in stone to produce casts for the fabrication of heat-activated acrylic resin denture bases (HB condition). A portable clinical motorized test stand and advance digital force gauge were modified to measure the amount of denture base retention in newtons. The denture bases were seated over the edentulous maxillary ridge and pulled 3 times vertically at 10-minute intervals without denture adhesive (MB and HB control conditions) and with denture adhesive (MBA and HBA test conditions). For statistical analysis, a repeated-measures ANOVA was performed (α=.05). RESULTS: The control MB condition had significantly higher retention values compared with all other conditions (P<.001). However, the use of adhesive significantly decreased the retention of the milled bases. No significant differences were found with or without the use of denture adhesive among heat-activated denture bases (P>.05). CONCLUSIONS: Significantly higher retention values were recorded with milled denture bases than heat-activated resin bases without the use of denture adhesive. However, denture adhesive did negatively affect the retention of milled complete dentures.

Obstructive Sleep Apnea Management: An Overview of the Literature.

PURPOSE: Different approaches have been proposed to treat obstructive sleep apnea (OSA). This article reviews a synopsis of the available literature regarding the management of OSA. METHODS: A comprehensive review of the literature on the management of OSA began with a search of English-language peer-reviewed manuscripts using PubMed and MEDLINE. The focus was on clinical research articles published between 1996 and 2016. A search of relevant dental journals was also completed. RESULTS: OSA can be managed through behavior management, continuous positive airway pressure (CPAP), oral appliances, and other therapies. Clinicians may select treatment modalities based on the severity of clinical presentation and the patient's symptoms. CONCLUSION: Studies showed an enhancement in the quality of life in many patients who have been treated with oral appliances, and patients in general prefer oral appliances over CPAP therapy or any other treatments for OSA because of its convenience.

Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities.

STATEMENT OF PROBLEM: As the cosmetic demands of patients increase, determining the appropriate dimensions of the maxillary anterior teeth has become increasingly relevant. The relationship between facial measurements and tooth size provide guidance for maxillary anterior tooth size selection. However, most publications on this topic have focused on the white population, and more data for tooth sizes and their proportions in other ethnicities are needed. PURPOSE: The purpose of this observational study was to investigate the relationship between the mesiodistal dimensions of the 6 maxillary anterior teeth and the bizygomatic width, interpupillary distance, intercanthal distance, interalar width, and intercommissural width of individuals of Asian, African-American, and white ethnicities. MATERIAL AND METHODS: Standardized digital images of 360 participants (120 Asian, 120 African-American, and 120 white) were used to measure facial segments. Individual dimensions of the 6 maxillary anterior teeth were measured using stone casts with digital sliding caliper. The combined width of the 6 maxillary anterior teeth on a straight line corresponded to the sum of the anterior tooth width. The means and standard deviations from descriptive measurements were calculated and analyzed for face and maxillary anterior tooth ratios and correlations. Statistical analysis was done using the Kruskal-Wallis procedure to compare facial and tooth parameters among the 3 ethnicities. Appropriate post hoc comparisons that adjusted for multiple testing were conducted when warranted (α=.05). The Spearman rho correlation, a nonparametric correlate of the Pearson correlation, was used to associate the facial and tooth parameters within the strata of sex and ethnicity. RESULTS: No consistent ratios were found among the examined facial dimensions and the mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities, except for the central incisor width-to-bizygomatic width ratio. No correlations were found between the facial dimensions and mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities except in Asian women. For Asian women, the intercommissural width correlated with the width of the central incisor (P=.001), the width of 2 central incisors (P=.001), the width of 4 incisors (P=.003), and the width of 6 maxillary anterior teeth (P=.005). CONCLUSIONS: No facial proportions by which the exact width of maxillary anterior teeth could be predicted were found in Asian, African-American, or white populations.

An Alternative Technique for the Fabrication of a Metal-Reinforced Interim Implant-Supported Fixed Prosthesis: A Clinical Report.

Despite advancements in restorative materials and techniques, complications with implant-supported fixed prostheses such as veneer fracture and material wear are very common and present with varying frequencies. Following these complications, repair of this type of prosthesis can be time-consuming and costly even in the hand of experience clinicians. Several techniques have proposed using the existing framework to minimize the cost of the repair for the patient; however, while the repairs are being performed, the patient will have to either wear an interim complete denture or no prosthesis, which might cause some inconvenience to the patient. This article will present a technique for the fabrication of a metal-reinforced interim implant-supported fixed prosthesis for patients to wear while the existing prosthesis is being repaired.

Comparison of retention between maxillary milled and conventional denture bases: A clinical study.

STATEMENT OF PROBLEM: Clinical studies comparing the retention values of milled denture bases with those of conventionally processed denture bases are lacking. PURPOSE: The purpose of this clinical study was to compare the retention values of conventional heat-polymerized denture bases with those of digitally milled maxillary denture bases. MATERIAL AND METHODS: Twenty individuals with completely edentulous maxillary arches participated in this study. Definitive polyvinyl siloxane impressions were scanned (iSeries; Dental Wings), and the standard tessellation language files were sent to Global Dental Science for the fabrication of a computer-aided design and computer-aided manufacturing (CAD-CAM) milled denture base (group MB) (AvaDent). The impression was then poured to obtain a definitive cast that was used to fabricate a heat-polymerized acrylic resin denture base resin (group HB). A custom-designed testing device was used to measure denture retention (N). Each denture base was subjected to a vertical pulling force by using an advanced digital force gauge 3 times at 10-minute intervals. The average retention of the 2 fabrication methods was compared using repeated ANOVA (α=.05). RESULTS: Significantly increased retention was observed for the milled denture bases compared with that of the conventional heat-polymerized denture bases (P<.001). CONCLUSIONS: The retention offered by milled complete denture bases from prepolymerized poly(methyl methacrylate) resin was significantly higher than that offered by conventional heat- polymerized denture bases.