Comparison of Periodontal Health and Marginal Bone Loss in Mandibular First Molar Single-Crown Dental Implants Placed in Different Positions.

The aim of the present study is to compare the periodontal health and marginal bone loss (MBL) between single-crown dental implants placed interdentally and mesial to the edentulous space. Patients treated with single-crown dental implants between 01/04/2014 and 01/04/2021 were included in the study. The included patients were divided into 2 groups. Group 1 consisted of single implant crowns inserted interdentally with a distal neighboring mandibular second molar and Group 2 consisted of single molar implant crowns inserted distally to the second premolar tooth without a neighboring second molar. The measurements for probing pocket depth, gingival index, and plaque index were made in both groups at the 60-month control session to evaluate periodontal health of the single-crown dental implants. The marginal bone levels of distal and mesial aspects of all implants were measured at the 60-month control session on panoramic radiographs. Forty-six and sixty-one patients were included in Groups 1 and 2, respectively. There was a significantly higher distal MBL in Group 2 compared with Group 1 (P < 0.05). Mesial MBL was higher in Group 1, however, this difference was not significant. The periodontal parameters of probing pocket depth, gingival index, and PI were all significantly higher in Group 1 compared with Group 2 at the 60-month control evaluation (P < 0.05). Single-crown dental implants placed interdentally may show decreased distal MBL and periodontal health compared with single-crown dental implants placed mesial to the edentulous space.

Initial Stability Measurements of Implants Using a New Magnetic Resonance Frequency Analyzer With Titanium Transducers: An Ex Vivo Study.

The establishment of dental implant stability is mandatory for successful osseointegration. Resonance frequency analysis (RFA) is the most frequently used method for the clinical measurement of implant stability. The purpose of the present study was to evaluate the reliability of the recently developed RF analyzer Penguin RFA and to compare it with the traditional RF analyzer Osstell ISQ. Sixty implants were inserted into fresh steer vertebrae and pelvis. Implant stability was measured using Penguin RFA by its transducers (multipegs) and Osstell ISQ by its transducers (smartpegs). Additionally, stability was measured by multipegs with Osstell ISQ and by smartpegs with Penguin RFA. The intraobserver and interobserver reliability of Penguin RFA were estimated by the intraclass coefficient (ICC). Mean implant stability quotients (ISQs) measured with Osstell ISQ were higher than the ISQs measured with Penguin RFA (P < .05). The intra- and interobserver reliability of Penguin RFA were considered as excellent (ICC > 0.7). For Osstell ISQ, no significance in ISQs was detected between the readings by smartpegs and multipegs (P > .05), while for Penguin RFA ISQs by smartpegs were significantly higher than the ISQs by multipegs (P <.05). The recently developed Penguin RFA is reliable and can be used in clinical practice for the measurement of dental implant stability regardless of the bone type. The multipegs originally manufactured for the Penguin RFA is also compatible with Osstell ISQ.

Wear resistance and microhardness of various interim fixed prosthesis materials.

The aim of the present study is to evaluate the wear resistance and microhardness of various interim fixed prosthesis materials with different chemical compositions and curing methods. One heat-cured and four self-cured acrylic resins, and three self-cured, one light-cured, and one dual-cured composite-based materials were tested. For microhardness, samples from each group were tested after storing either at 37°C in artificial saliva for 7 days, followed by thermocycling, or in distilled water solution at 37°C for 24 h. For the evaluation of wear, the remaining samples were evaluated using a 3D scanner and a surface analysis program before loading in the chewing simulator and after every 10,000 cycles. There was a significant difference in wear behavior among the materials tested at both 10,000 and 20,000 cycles (P < 0.001). Microhardness and wear resistance were significantly different between acrylic and composite materials.

A Comparison of the Color Stability of Conventional and CAD/CAM Polymethyl Methacrylate Denture Base Materials.

OBJECTIVE: The aim of this study was to evaluate the color stability of a heat polymerized resin, an auto-polymerizing resin, a urethane dimethacrylate resin and a CAD/CAM PMMA block resin stored in different storage media. MATERIALS AND METHODS: 60 disc-shaped specimens (15×2 mm) were fabricated for each group. A total of 240 disc-shaped specimens were thermal-cycled for 5,000 cycles. Then specimens were randomized into 4 groups (n= 15) according to storage media: coffee, coke, red wine and distilled water (control group). The color measurement of each sample was performed using a spectrophotometer before and after storage (after 7 and 30 days), and color changes (ΔE) were calculated. RESULTS: All the denture base materials demonstrated dissimilar color changes after stored in the different storage media in both evaluation stages. In all storage media, CAD-CAM denture base resins showed the minimum in color change. In all denture base resins, red wine showed a higher degree of color change than coke or coffee. CONCLUSION: The color stability of CAD-CAM denture base resins is better than any of the other kind of denture base resins. The color change values of all groups except Eclypse stored in red wine had clinically detectable values.

Is clinical experience important for obtaining the primary stability of dental implants with aggressive threads? An ex vivo study

Background: The aim of this study was to investigate the clinicians' experience on maintaining the primary stability of implants with aggressive threads belonging to a novel dental implant system. Material and Methods: Three hundred implants with aggressive threads were inserted in fresh bovine ribs mimicking Type IV bone by five clinicians which were classified according to their previous experience of total number of implant insertion. An independent examiner measured the primary stability of all implants after insertion by using resonance frequency analysis (RFA), electronic percussive testing (EPT) and removal torque methods. Results: No significant differences were detected between the stability values measured by the clinicians (p> 0.05) except the Periotest values (PTVs) of the non-experienced clinician. PTVs of the non-experienced clinician were significantly higher than the PTVs of the expert and good clinicians (p<0.05). Significantly higher stability values were detected in the secondary insertion of the non-experienced clinician as compared to her initial insertion values (p<0.05). No significant differences were detected between the first and second measurements of the other clinicians (p> 0.05). Conclusions: Within the limitations of this ex-vivo study, it may be concluded that experience does not play an important role in maintaining the stability of implants with aggressive threads

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The Influence of Implant Shape on Primary Stability of Implants With a Thread Cutting and Forming Design: An Ex Vivo Study.

The design of an implant has a great effect on primary stability. The purpose of this study was to determine the differences in primary stability between straight and tapered Neoss ProActive implants in type I and type III bones using resonance frequency analysis (RFA) and electronic percussive testing (EPT) methods. Fresh cow vertebrae and pelvis were used as models of type III and type i bone, respectively. Implants of 2 different designs-straight and tapered Neoss ProActive implants with a thread cutting and forming (TCF) design, both 3.5-mm wide and 11-mm long-were placed in both types of bone (n = 60). The primary stability of all implants was measured by an experienced clinician blinded to the study protocol using the EPT and RFA devices. No statistically significant difference was found between the implant stability quotients and the percussive test values of straight and tapered implants in either bone type. Within the limitations of this ex vivo study, it may be concluded that the shape of an implant with a TCF design does not affect primary stability.

The behavior of polyetheretherketone healing abutments when measuring implant stability with electronic percussive testing.

BACKGROUND: It is unknown whether it is possible to measure implant stability with polyetheretherketone (PEEK) healing abutments using electronic percussive testing (EPT). PURPOSE: To investigate the reliability of the percussive test values (PTVs) measured with PEEK healing abutments and to compare them with the PTVs measured with titanium healing abutments. MATERIAL AND METHODS: Thirty dental implants were inserted into the fresh pelvis belonging to a cow. Titanium healing abutments (2 and 5 mm), PEEK healing abutments (5 mm), and prepable standard titanium abutments (5 mm) were screwed to the implants, respectively, and PTVs were measured by two examiners using a wireless EPT device. Differences in PTVs between different dental implant components were evaluated using Friedman's test with post hoc Wilcoxon signed-rank test and Bonferroni correction. Inter and intra-observer reliabilities were detected using interclass correlation coefficients (ICCs) RESULTS: The mean PTVs obtained using the PEEK healing abutments were significantly higher than the mean PTVs obtained using the other abutments for both examiners (P < .01). The ICCs for intra-observer reliability were detected as poor for PEEK healing abutments; and excellent for the other abutment types for both examiners. The ICCs for the inter-observer reliability between the two examiners were poor (0.25) for PEEK healing abutments, and excellent for the 2 and 5 mm titanium healing abutments and for standard abutments (0.82, 0.84 and 0.93, respectively). CONCLUSION: Within the limitations of this in vitro study, it may be concluded that EPT measurements should be avoided using PEEK healing abutments because of the poor reliability.

Evaluation of volumetric wear of abutments on the retention loss of ball attachment systems in implant-retained overdentures: An in vitro study.

BACKGROUND: There is a lack of studies evaluating the wear of the male components of the ball attachment systems of implant-retained overdentures. PURPOSE: The purpose of this study was to compare the volumetric wear patterns four commercially used ball abutments. MATERIALS AND METHODS: Forty-eight identical polyethylene and acrylic blocks were fabricated and four groups consisting of 12 polyethylene blocks with two implants and 12 acrylic blocks, which were used as overdentures, were generated (two groups with plastic females, one group with gold and one group with titanium females). Every specimen underwent 5000 insertion and removal cycles (~4.5 years) and retention forces were measured. For the evaluation of volumetric wear, all the ball abutments were scanned before and after the 5000 cycles using a three-dimensional scanner and the data were analyzed using the software supplied by the manufacturer. RESULTS: Statistically significant retention force differences were observed between the groups at each cycle (P < .05). Among the four groups, retention force was lowest in the group with titanium females (5.59 ± 2.27) and highest in the group with gold females (43.0 ± 6.3) at the end of 5000 cycles. Statistically significant dimensional changes in the male components were observed between the groups (P < .05). Volumetric losses were 11%-13% in Group I and II, 1% in Group III, and 25% in Group IV. Group III showed significantly lower volumetric wear whereas Group IV showed significantly higher volumetric wear than all the other groups (P < .001). No significance was detected between Group I and II (P > .05). CONCLUSION: Within the limitations, it can be concluded that although clinical studies are needed to ensure the findings of the present study, due to severe retention loss and volumetric abutment wear, ball attachments with titanium female components should be used with caution.

Comparison of patient satisfaction, quality of life, and bite force between elderly edentulous patients wearing mandibular two implant-supported overdentures and conventional complete dentures after 4 years.

This study compared two groups of patients who were elderly and edentulous, one group included subjects who had mandibular overdentures supported by two implants (Group I); the other groups wore conventional complete dentures (Group II). This retrospective study included 100 edentulous patients (50 from each group) with an average age of 67.86 years, who had been followed for 4 years. The groups were compared in terms of patient satisfaction, quality of life (QOL), and bite force. The bite force and patient satisfaction scores of Group I were found to be statistically significantly higher than Group II (p < .05). However, no statistically significant difference was found between the two groups' QOL scores (p > .05) except on the physical pain subscale (p = .013). Based on these results, it can be concluded that after 4 years of function, subjects wearing mandibular overdentures supported by two implants had higher values for bite force and patient satisfaction scores, but similar QOL scores when compared to conventional complete denture-wearers.