Reliability of implant stability measuring devices depending on various clinical conditions: an in vitro study.

PURPOSE: The aim of this study was to evaluate the reliability of implant stability measuring devices depending on the location of the implant and the position of the patient. MATERIALS AND METHODS: Six implants were installed in different dentate sextants of six artificial bone models. Implant stability was measured in three conditions of the bone model (without mounting on a phantom head, mounted on a phantom head in supine position, and mounted on a phantom head in upright position). A resonance frequency analysis device (Osstell) and two damping capacity analysis devices (Periotest and Anycheck) were used to measure implant stability. The values measured outside the phantom head were treated as controls, and the values inside the phantom head were compared using an independent t-test. RESULTS: Osstell showed different results in two of the six divisions in both the supine and upright positions compared to outside of the mouth (P < .05). Periotest showed different results in all six parts in the supine position and in five parts in the upright position compared to outside of the mouth (P < .05). While Anycheck showed different results in five areas in the supine position compared to outside of the mouth, it showed different results in only one area in the upright position (P < .05). CONCLUSION: In the difficult implant position for the operator to access, the implant stability measuring devices show less reliability. The accessibility of implant is greatly affected in the order of Osstell, Anycheck, and Periotest.

Narrow-diameter versus regular-diameter dental implants for mandibular overdentures: A systematic review and meta-analysis.

PURPOSE: The aim of this systematic review was to compare treatment outcomes in terms of implant survival rate, marginal bone loss, and patient-reported outcome measures (PROMs) between narrow-diameter implants and regular-diameter implants (RDIs) for mandibular implant overdentures (MIOs). METHODS: This study was based on the methodology adapted as per Cochrane. Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched for pertinent studies published by July 22, 2022. Outcome parameters included in this meta-analysis were implant survival rate, marginal bone loss, visual analogue scale score for patient satisfaction, and value of oral health impact profile. RESULTS: A total of 782 non-duplicate articles and 83 clinical study registrations were identified from database and hand searches, of which 26 were eligible for full-text searches. Finally, 12 publications reporting on 8 independent studies were included in this review. In the meta-analysis, implant survival rate and marginal bone loss did not significantly differ between narrow-diameter implants and RDIs. Regarding RDIs, narrow-diameter implants were associated with significantly better outcomes in general patient satisfaction and oral health-related quality of life than RDIs for mandibular overdentures. CONCLUSIONS: Narrow-diameter implants have competitive treatment outcomes compared to RDIs in terms of implant survival rate, marginal bone loss, and PROMs. [Correction added on July 21, 2023, after first online publication: The abbreviation RDIs was changed to PROMs in the preceding sentence.] Thus, narrow-diameter implants might be an alternative treatment option for MIOs in situations with limited alveolar bone volume.

Mini-implant mandibular overdentures under a two-step immediate loading protocol: A 4-6-year retrospective study.

OBJECTIVES: This retrospective study to evaluate the treatment outcomes of mandibular mini-implant overdentures (MIODs) placed under a two-step immediate loading protocol. BACKGROUND: The mini-implant overdenture emphasises the advantages of simplicity using flapless surgery and immediate loading. However, some mini-implant have lowe initial stability. MATERIALS AND METHODS: A total of 30 participants who used mandibular MIODs and maxillary removable complete dentures (RCDs) over 4 years were included. Four one-piece mini-implants (<3 mm in diameter) were placed by a flapless surgical approach after fabrication of new RCDs, and the O-ring attachment was attached at least 8 weeks after implant placement. RESULTS: The average observation period was 58.9 ± 9.2 months after mini-implant loading. The survival rate of the implants was 100.0%, and the overall change in mean marginal bone level (ΔMBL) was -0.9 ± 1.1 mm. The implant success rate was 83.3% at the implant level, and 66.7% at the patient level. The mean initial Periotest value was 0.9 ± 3.1, and it was positively associated with ΔMBL and implant success (P < .05). Patient satisfaction improved after conversion from RCDs to MIODs (P < .05), and mastication and pain showed greater satisfaction with longer loading time (P < .05). CONCLUSIONS: The mandibular MIODs could be chosen as an alternative treatment under a two-step immediate-loading protocol in edentulous patients with limited alveolar bone volume. To ensure superior treatment outcomes of MIODs, initial stability of implant must be obtained using as wide a diameter as possible within the anatomically allowable limits.

Accuracy of implant impression techniques with a scannable healing abutment.

STATEMENT OF PROBLEM: Scannable healing abutments are a convenient option to facilitate impression making for implant-supported restorations. However, studies evaluating the accuracy of the impression technique with scannable healing abutments are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy of implant impression techniques with scannable healing abutments. MATERIALS AND METHODS: A partially edentulous mandibular dentiform model was fabricated with an epoxy resin, and implants were placed in the mandibular right second premolar and first molar areas. A maxillary dentiform model was then fabricated, and both models were mounted on an articulator. Scan data were obtained from the mounted models and set as the reference scans. The experimental models were divided into 4 groups (n=10). The conventional pick-up impression technique and definitive casts were used in group CI. The scan data from the definitive casts were obtained with a 3D model scanner. An intraoral scanner with a digital body scan was used in group DS. Group MS yielded definitive casts with dual-arch impressions with scannable healing abutments. The fabricated definitive casts were mounted and scanned with a 3D cast scanner. Intraoral scanning with scannable healing abutments was used in group IS. In all 4 groups, the interarch relationship in the maximum intercuspal position was obtained by scanning the facial aspect. The center of the implant head was set as a measurement point for linear intra-arch deviations and implant angle deviations. The mesiopalatal cusp tip of the maxillary right first molar was used to calibrate the linear interarch deviations. The data obtained from each group were compared with the data from the reference scan. As the data were not normally distributed, the Kruskal-Wallis test and Bonferroni correction were used for the analysis (α=.05). RESULTS: Group MS exhibited significantly higher deviations in linear intra-arch and implant angles compared with the other groups (P<.05). No significant difference was found between the groups in linear interarch deviations (P>.05). CONCLUSIONS: The accuracy of intraoral scanning with scannable healing abutments was comparable with that of conventional pick-up impression techniques and digital scans with scan bodies. However, model scanning with scannable healing abutments may not be clinically acceptable for implant impressions.

Influence of an Implant Fixture including a Freely Removable Micro-Locking Implant Prosthesis on Peri-Implant Tissues and Implant Prostheses: A Prospective Clinical Study.

This prospective study was undertaken to evaluate the clinical usefulness of a newly developed one-piece, screw-free, and micro-locking implant system, which was designed to overcome the shortcomings of the existing implant systems. Thirty-eight patients were recruited and randomly and equally assigned to an experimental group (micro-locking one-piece fixture, MLF; n = 19) or a control group (micro-locking abutment, MLA). Cumulative implant survival rates, marginal bone resorptions, probing depths, plaque indices, bleeding indices, and complications were obtained by using clinical and radiographic findings at 6 months and 12 months after prosthesis placement. Complications that occurred multiple times for single implants were counted. During the 12 month observation period, survival rates were 100% in both groups. No significant intergroup differences were observed for marginal bone resorption, probe depth, or bleeding index. However, mean plaque index was significantly lower in the MLF group at 12 months (p < 0.05). During the 12-month observation period, food impaction (26.3%) was the main complication in the MLF group and screw loosening (5.3%), prosthesis detachment (5.3%), and food impaction (5.3%) were observed in the MLA group. The results of this study suggest that the one-piece micro-locking implant system offers a predictable treatment method.

Color stability of provisional restorative materials with different fabrication methods.

PURPOSE: The aim of this study was to investigate and compare the color stability of provisional restorative materials fabricated by 3D printing, dental milling, and conventional materials. MATERIALS AND METHODS: For the experimental groups, two commercially available 3D-printing provisional resins (E-Dent 100; EnvisionTEC GmbH, Germany & VeroGlaze™; Stratasys®, USA), two dental milling blocks (PMMA Disk; Yamahachi Dental Co., Japan & Telio®CAD; Ivoclar Vivadent AG, Liechtenstein), and two conventional materials (Alike™; GC Co., Japan & Luxatemp automix plus; DMG, Germany) were used. The water sorption and solubility test were (n=10, respectively) carried out according to ISO4049:2000 (International Standards Organization, Geneva, Switzerland). For the color stability test (n=10), coffee and black tea were used as staining solutions, and the specimens were stored for 12 weeks. Data were analyzed by one-way ANOVA and Tukey's HSD using SPSS version 22.0 (SPSS Inc. Chicago, IL, USA) (P<.05). RESULTS: Alike and Veroglaze showed the highest values and Luxatemp showed the lowest water sorption. In the color stability test, the ΔE of conventional materials varied depending on the staining solution. PMMA milling blocks showed a relatively low ΔE up to 4 weeks, and then significantly increased after 8 weeks (P<.05). 3D-printed materials exhibited a high ΔE or a significant increase over time (P<.05). CONCLUSION: The degree of discoloration increased with time, and a visually perceptible color difference value (ΔE) was shown regardless of the materials and solutions. PMMA milled and 3 D-printed materials showed more rapid change in discoloration after 8 weeks.

The reliability of Anycheck device related to healing abutment diameter.

PURPOSE: The purpose of this in vitro study was to examine the reliability of the Anycheck device and the effect of the healing abutment diameter on the Anycheck values (implant stability test, IST). MATERIALS AND METHODS: Thirty implants were placed into three artificial bone blocks with 10 Ncm, 15 Ncm, and 35 Ncm insertion torque value (ITV), respectively (n = 10). (1) The implant stability was measured with three different kinds of devices (Periotest M, Osstell ISQ Mentor, and Anycheck). (2) Five different diameters (4.0, 4.5, 4.8, 5.5, and 6.0 mm) of healing abutments of the same height were connected to the implants and the implant stability was measured four times in different directions with Anycheck. The measured mean values were statistically analyzed. RESULTS: The correlation coefficient between the mean implant stability quotient (ISQ) and IST value was 0.981 (P<.01) and the correlation coefficient between the meant periotest value (PTV) and IST value was -0.931 (P<.01). There were no statistically significant differences among the IST values with different healing abutment diameters. CONCLUSION: There was a strong correlation between the Periotest M and Anycheck values and between the ISQ and IST. The diameter of the healing abutment had no effect on the Anycheck values.

Effects of type of magnet attachment and implant angulation in two implant overdenture models.

PURPOSE: The purpose of this study is to evaluate the effects of type of magnet attachment and implant angulation in two implant overdenture models. MATERIALS AND METHODS: Magnet attachments used in this study were flat and dome types (MGT5515, MGT5520D, Dentium Co., Seoul, Korea). Two implants with keepers were inserted in the resin blocks at a distance of 24 mm. For the first model, the implants were parallel to the vertical and perpendicular to the horizontal; for the second model, both were angulated 5 degrees to the mesial; for the third model, both were angulated 10 degrees toward the mesial. The retentive force was measured in both vertical and lateral directions. Statistical analyses were performed using SPSS software version 22.0 (α=.05). RESULTS: The flat type magnet attachment showed the highest lateral retentive force in the 20° divergent group (P<.05) and the dome type magnet attachment showed the highest lateral retentive force in the parallel group (P<.05). The vertical and lateral retentive force of the dome type magnet attachment was greater than that of the flat type magnet attachment in every direction (P<.05). CONCLUSION: Within the limitations of this study, the dome shape magnet attachment can resist vertical and lateral retentive force more superiorly than the flat type magnet attachment, regardless of angle, in the mandibular two implant model.

Effect of conversion to implant-assisted removable partial denture in patients with mandibular Kennedy classification â : A systematic review and meta-analysis.

OBJECTIVE: This review evaluated the change in treatment outcomes after conversion from conventional removable partial denture (RPD) to implant-assisted removable partial denture (IARPD). The patient-reported outcome measures (PROMs), objective parameters for evaluation of functional performance, and biological and mechanical complication were evaluated. MATERIALS AND METHODS: This systematic review was based on the Cochrane review methodology and followed the criteria of the preferred reporting items for systematic reviews and meta-analyses (PRISMA). We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus up to April 3, 2019. After the initial search, additional electronic and hand searches were performed to identify further studies, ongoing studies, and gray literature, without restrictions on language, year of publication, or publication type. RESULTS: In total, 6,544 non-duplicate articles were identified, and 31 were eligible for full-text search. Finally, 19 publications based on 13 independent studies were selected. In the meta-analysis, general patient satisfaction was significantly increased (p < .05), and the improved mastication was remarkable oral function. In oral health-related quality of life, the oral health impact profile score was significantly improved, and improvements of physical pain and psychological disability were prominent (p < .05). Masticatory performance was improved in terms of maximum bite force, active occlusal contact area, and mandibular jaw movement (p < .05). The weighted mean survival rate of implants was 96.60%. CONCLUSIONS: After conversion from conventional RPD to IARPD, the PROMs and masticatory performance significantly improved in partially edentulous patients under mandibular Kennedy classification I.

Bar versus ball attachments for maxillary four-implant retained overdentures: A randomized controlled trial.

OBJECTIVES: To compare the clinical treatment outcomes of maxillary four-implant retained overdentures with either splinted (bar) attachments or non-splinted (ball) attachments. MATERIAL AND METHODS: Forty participants who were dissatisfied with their existing conventional maxillary complete dentures were included in this randomized controlled trial. Six months after implant placement, a definitive prosthesis was inserted. Implant success, condition of peri-implant tissue, prosthodontic maintenance and complications, and patient satisfaction were assessed. Outcomes were recorded at baseline, prosthesis delivery, and at 3 and 12 months following prosthesis delivery, and a statistical analysis was performed. RESULTS: Thirty-two of the forty patients completed the 1-year follow-up and had their treatment outcomes evaluated. The mean marginal bone loss after 1 year of loading was 0.34 ± 0.88 mm, and there were no significant differences between the two groups. Plaque index, gingival index and bleeding on probing were significantly higher in the bar group (p<.001), and the implant success rate of the bar group was significantly lower than that of the ball group (p=.028). The most frequent prosthodontic maintenance and complication issue was the need to change the bar clip or O-ring as a result of retention loss. Patient satisfaction did not differ between the two groups except for aesthetics at 3 months. CONCLUSIONS: Within the limitations of this study, the maxillary 4-implant retained overdenture exhibited predictable results regardless of the attachment systems (ball or bar) in the 1-year follow-up period. The bar group was more vulnerable than the ball group with respect to maintaining peri-implant tissue health.

Physical properties and color stability of injection-molded thermoplastic denture base resins.

PURPOSE: The purpose of this study was to compare mechanical and physical properties of injection-molded thermoplastic denture base resins. MATERIALS AND METHODS: In this study, six commercially available products (VA; Valplast, LC; Lucitone, ST; Smiltone, ES; Estheshot-Bright, AC; Acrytone, WE; Weldenz) were selected from four types of thermoplastic denture base materials (Polyamide, Polyester, Acrylic resin and Polypropylene). The flexural properties and shore D hardness have been investigated and water sorption and solubility, and color stability have evaluated. RESULTS: For the flexural modulus value, ES showed the highest value and WE showed significantly lower value than all other groups (P<.05). Most of experimental groups showed weak color stability beyond the clinically acceptable range. CONCLUSION: Within the limits of this study, thermoplastic denture base resin did not show sufficient modulus to function as a denture base. In addition, all resins showed discoloration with clinical significance, and especially polyamides showed the lowest color stability.

Effect of non-thermal plasma on the shear bond strength of resin cements to Polyetherketoneketone (PEKK).

PURPOSE: This study aimed to assess the effect of non-thermal plasma on the shear bond strength of resin cements to polyetherketoneketone (PEKK) in comparison to other surface treatment methods. MATERIALS AND METHODS: Eighty PEKK discs were subjected to different surface treatments: (1) Untreated (UT); (2) Non-thermal plasma (NTP); (3) Sandblasting with 50 µm Al2O3 particles (SB); and (4) Sandblasting + Non-thermal plasma (SB+NTP). After each surface treatment, the contact angle was measured. Surface conditioning with Visio.Link was applied in all groups after pre-treatment. RelyX Unicem resin cement was bonded onto the PEKK specimens. After fabrication of the specimens, half of each group (n=10) was initially tested, while the other half was subjected to thermocycling (5℃ to 55℃ at 10,000 cycles). Shear bond strength (SBS) testing was performed using a universal testing machine, and failure modes were assessed using stereomicroscopy. The SBS results were analyzed statistically using one-way ANOVA followed by Tukey's post hoc test. Independent t-test was used to examine the effect of thermocycling (P<.05). RESULTS: The highest SBS values with or without thermocycling were observed with PEKK specimens that were treated with SB+NTP followed by the SB group. The lowest SBS results were observed in the UT groups. CONCLUSION: The shear bond strength between PEKK and resin cements was improved using non-thermal plasma treatment in combination with sandblasting.

Effects of relining materials on the flexural strength of relined thermoplastic denture base resins.

PURPOSE: The aim of this study was to evaluate the effects of relining materials on the flexural strength of relined thermoplastic denture base resins (TDBRs). MATERIALS AND METHODS: For shear bond strength testing, 120 specimens were fabricated using four TDBRs (EstheShot-Bright, Acrytone, Valplast, Weldenz) that were bonded with three autopolymerizing denture relining resins (ADRRs: Vertex Self-Curing, Tokuyama Rebase, Ufi Gel Hard) with a bond area of 6.0 mm in diameter and were assigned to each group (n=10). For flexural strength testing, 120 specimens measuring 64.0×10.0×3.3 mm (ISO-1567:1999) were fabricated using four TDBRs and three ADRRs and were assigned to each group (n=10). The thickness of the specimens measured 2.0 mm of TDBR and 1.3 mm of ADRR. Forty specimens using four TDBRs and 30 specimens using ADRRs served as the control. All specimens were tested on a universal testing machine. For statistical analysis, Analysis of variance (ANOVA) with Tukey's test as post hoc and Spearman's correlation coefficient analysis (P=.05) were performed. RESULTS: Acry-Tone showed the highest shear bond strength, while Weldenz demonstrated the lowest bond strength between TDBR and ADRRs compared to other groups. EstheShot-Bright exhibited the highest flexural strength, while Weldenz showed the lowest flexural strength. Relined EstheShot-Bright demonstrated the highest flexural strength and relined Weldenz exhibited the lowest flexural strength (P<.05). Flexural strength of TDBRs (P=.001) and shear bond strength (P=.013) exhibited a positive correlation with the flexural strength of relined TDBRs. CONCLUSION: The flexural strength of relined TDBRs was affected by the flexural strength of the original denture base resins and bond strength between denture base resins and relining materials.

Corrigendum to "Effects of rhBMP-2 Loaded Titanium Reinforced Collagen Membranes on Horizontal Bone Augmentation in Dogs".

[This corrects the article DOI: 10.1155/2017/7141296.].

Two-Step Immediate Loading of Mandibular Overdentures Retained by Mini-implants: A Prospective Clinical Study.

PURPOSE: This study aimed to evaluate treatment outcomes of mandibular overdentures retained by two different mini-implant systems with ball attachments under a two-step immediate loading protocol. MATERIALS AND METHODS: This clinical trial investigated treatment outcomes of mandibular mini-implant overdentures in 45 edentulous patients. MDI implants (3M ESPE) and SlimLine implants (Dentium) were randomly selected for placement in the anterior mandible in each group (MDI = 21; SlimLine = 24) with a flapless surgical approach. The side of the tissue in the region of the complete mandibular denture where mini-implants were placed was immediately relined with soft reliner (COE-SOFT). The female components were attached on the dentures 2 months after implant placement. Clinical and radiographic data were collected during follow-up. Statistical analyses were performed using SPSS software version 22.0 (α = .05). RESULTS: A total of 177 mini-implants were inserted in the anterior mandibles of 45 totally edentulous patients. There were five implant failures (97.2% success rate) and no significant differences between the two implant groups. Most mini-implants showed stable initial Periotest values (a mean ± standard deviation of 1.03 ± 3.65 mm) and a mean marginal bone loss of 0.50 ± 0.75 mm at 12 months. Multiple regression analysis revealed that implants ≤ 2.4 mm in diameter had higher Periotest values than those ≥ 2.8 mm. Intial Periotest values significantly influenced implant failure (P < .05). CONCLUSION: There were no significant differences in treatment outcomes between patients treated with MDI or SlimLine implants. Mini-implants with wider diameters showed higher initial stability than those with narrow diameters, which may influence implant survival.

Corrigendum to "Biomechanical Evaluation of a Tooth Restored with High Performance Polymer PEKK Post-Core System: A 3D Finite Element Analysis".

[This corrects the article DOI: 10.1155/2017/1373127.].

Effects of rhBMP-2 Loaded Titanium Reinforced Collagen Membranes on Horizontal Bone Augmentation in Dogs.

The aim of this study was to evaluate the efficacy of growth factor loaded collagen membranes on new bone formation during horizontal bone augmentation. Mandibular defects (4 × 4 × 4 mm) were surgically prepared in six male beagle dogs, which were then protected with one of three types of membranes: (1) titanium mesh, (2) titanium reinforced collagen, or (3) rhBMP-2 loaded titanium reinforced collagen. Animals were euthanized 8 and 16 weeks after surgery, and nondecalcified specimens were prepared and histomorphologically investigated to determine the degree of osteogenesis. Data were analyzed with Friedman test. With respect to the degree of osteogenesis at earlier stage (8 weeks after surgery), there was significantly higher new bone ratio in rhBMP-2 loaded membrane group (p > 0.05). However, with respect to the long-term results (16 weeks after surgery), there were no significant differences among the three membranes (p > 0.05). Based on histomorphometric analysis, there were no significant differences in horizontal bone gaining ratio (p > 0.05).

Effects of desensitizing agents for cervical dentin hypersensitivity: A randomized clinical trial.

PURPOSE: To evaluate the clinical efficacy of five commercially available desensitizing agents with different mechanisms applied to hypersensitive teeth. METHODS: A randomized clinical trial was conducted on subjects suffering dentin hypersensitivity in Korea University Guro Hospital from October 2013 to April 2015. A total of 64 subjects met the selection criteria and were randomly assigned to five commercially available desensitizing agents, and applied according to the manufacturers' instructions. Before and after application of desensitizing agents, subjects were evaluated with the Visual Analogue Scale (VAS) at baseline, 1 week, 1 month and 3 months. The difference between the degree of reduction of hypersensitivity in relation to time were evaluated with the repeated-measures ANOVA (P<0.05). RESULTS: Practitioner and subject-measured VAS values at 1 week, 1 month and 3 months showed a significant difference in all products compared with the first visit. On the other hand, no statistically significant differences between the products was shown. Desensitizing agents used in this clinical trial relieved dentin hypersensitivity up to 3 months. CLINICAL SIGNIFICANCE: The five tested desensitizing agents with different mechanisms were clinically effective in relieving dentin hypersensitivity up to 3 months and showed statistically significant pain reduction when compared to baseline scores.

Shear bond strength of composite resin to high performance polymer PEKK according to surface treatments and bonding materials.

PURPOSE: The object of the present study was to evaluate the shear bonding strength of composite to PEKK by applying several methods of surface treatment associated with various bonding materials. MATERIALS AND METHODS: One hundred and fifty PEKK specimens were assigned randomly to fifteen groups (n = 10) with the combination of three different surface treatments (95% sulfuric acid etching, airborne abrasion with 50 µm alumina, and airborne abrasion with 110 µm silica-coating alumina) and five different bonding materials (Luxatemp Glaze & Bond, Visio.link, All-Bond Universal, Single Bond Universal, and Monobond Plus with Heliobond). After surface treatment, surface roughness and contact angles were examined. Topography modifications after surface treatment were assessed with scanning electron microscopy. Resin composite was mounted on each specimen and then subjected to shear bond strength (SBS) test. SBS data were analyzed statistically using two-way ANOVA, and post-hoc Tukey's test (P<.05). RESULTS: Regardless of bonding materials, mechanical surface treatment groups yielded significantly higher shear bonding strength values than chemical surface treatment groups. Unlike other adhesives, MDP and silane containing self-etching universal adhesive (Single Bond Universal) showed an effective shear bonding strength regardless of surface treatment method. CONCLUSION: Mechanical surface treatment behaves better in terms of PEKK bonding. In addition, self-etching universal adhesive (Single Bond Universal) can be an alternative bonding material to PEKK irrespective of surface treatment method.