International Journal of Implant Dentistry最新文献

The aim of this study was to investigate in-vitro the temperature changes occurring in the bone during drilling with implant drills manufactured by different companies. Bone blocks obtained from fresh bovine ribs were used in the study. Bone blocks were drilled with drills manufactured by Ankylos, Astra Tech, Nobel Biocare, Bredent and Straumann implant brands at an ambient temperature of 30 ± 2° C under a constant pressure of 2 kg. Two K-type thermocouple sensors were placed on the bone blocks at 5th and 10th mm depths and the temperature changes were measured at a distance of 1 mm from the implant drill. In the study, working models were created under different conditions for implant socket preparation. In group 1, the first time drills were used at 150 rpm without irrigation, in group 2, the first time drills were used at 1200 rpm with 40 ml/min irrigation, in group 3, the 30th time drills were used at 150 rpm without irrigation, and in group 4, the 30th time drills were used at 1200 rpm with 40 ml/min irrigation. All osteotomy procedures were performed with 3.5 ± 0.3 mm diameter burs for a period of 8 s and the temperature values obtained at equal time intervals were recorded. Repeated Measures and Kruskall Wallis-H tests were used for statistical analysis of the data. No significant difference was observed between the implant drills and the temperature changes in the bone during drilling (p < 0.05). None of the groups reached critical temperature values (47° C+) throughout the study. At the 5th and 10th mm depths, the temperature changes in the sensors used were close to each other. It was also calculated that although the average temperatures were close to each other in the non-irrigated and irrigated systems, the difference values obtained by subtracting the initial temperature were significantly higher in the non-irrigated systems. The results showed that implant drills did not cause significant temperature increases in bone blocks depending on the difference in manufacturers (Ankylos, Astra Tech, Nobel Biocare, Bredent, Straumann) and the number of uses. It was also concluded that irrigated and non-irrigated systems are safe as long as they are used under the recommended conditions.

Background: Dental implant systems provide standard cylindrical healing abutments of various diameters; however, they do not match the larger shape of the complex emergence profile of the prosthetic crowns. Adaptation of the soft tissues from a circular emergence profile to the one that suits the prosthetic crown involves a simultaneous squeezing and stretching of the gingiva. Often, this translates into local blanching of the gingiva and the prosthodontist must assess that blanching is transient. There is no literature about how much strain exerted by the prosthetic crown is leading or not to gingiva blanching. Aim of this paper is to present a digital workflow that allows measuring, upon prosthesis delivery, how much the strained gingiva is displaced under the crown and leads or not to blanching of the peri-implant soft tissues.

Method and results: The digital workflow involves 3 intra-oral scans (IOS), IOS#1 at completion of the soft tissue healing, IOS#2 at prosthesis delivery, IOS#3 after soft tissue conditioning, and the STL files of the healing cap, the abutment, the implant and the prosthetic crown. The above are superposed and merged following a dedicated protocol that provides access to the distance the delivered crown deforms the strained gingiva. The present case study displayed distinct blanching intensities. Severe blanching was present when the strains applied to the gingiva caused a displacement of 1.3 mm and above; a displacement of 0.9 mm led to moderate blanching. No blanching was observed up to a displacement of 0.6 mm.

Conclusion: A digital protocol, involving the superposition and merging of IOSs taken along a defined timeline and STLs of the implant hardware, allowed measuring the displacement distances a prosthetic crown wields upon delivery on the gingiva beneath the prosthesis. Various intensities of gingiva blanching could be related to distinct displacement distances of the healed gingiva that were triggered by attaching a prosthetic crown to the implant neck.

Purpose: To retrospectively evaluate the outcome of implant-supported or combined tooth-implant-supported prostheses retained by electroplated double-crowns after 1-12 years.

Methods: Twenty-five patients were retrospectively examined in a private dental practice in Hamburg, Germany. All had been rehabilitated with a removable prosthesis retained by electroplated double-crowns, for at least one year. Fifteen patients had implant-supported prostheses and 10 had combined tooth-implant-supported prostheses in the maxilla or the mandible. Biological and technical complications were recorded at the clinical examination and extracted from the patient records. Kaplan-Meier implant and tooth survival rates were calculated. Potential risk factors for severe complications were identified. Oral health-related quality of life (OHRQoL) was measured by a short version of the Oral Health Impact Profile (OHIP) questionnaire. Patients reported subjective chewing function using a visual analogue scale.

Results: Kaplan-Meier survival rates were 100% for natural abutments and 90.9% for implants after 11.8 years (p = 0.54). Two implants in two patients were lost at 8 and 9 years due to peri-implantitis in the "solely implant" group. The most common complications were decementation of primary crowns and wear of the prosthetic teeth. The mean OHIP score for the group "tooth-implant-supported" was 5.2 ± 5.0, whereas the mean score for the "solely implant" group was 1.7 ± 2.9 (p = 0.039). Patients rated their subjective masticatory function very high with an average score of 9.4 ± 0.8 out of a possible 10.

Conclusions: Implant-supported or combined tooth-implant-supported prostheses retained by electroplated double-crowns are a viable method of treatment with a satisfactory outcome. Maintenance has been manageable and patients have reported very good subjective chewing function after several years of function.

Background: Between adjacent dental implants, an interimplant distance (IID) of at least 3 mm has been recommended to avoid resorbing the interproximal crestal bone. The effect of a 2 mm IID on crestal bone loss has been investigated but the literature is scarce when it comes to an IID of 1 mm. There is a need to document such clinical situations when they occur and elucidate if such a narrow IID is deleterious or not to the interproximal crest. The present case deals with an IID of 1 mm in the premolar area where, for the first time, the fate of an interimplant crest is reported after a 10-year follow-up.

Case presentation: A 57-year-old patient attended with 2 hopeless maxillary premolars. The mesio-distal space available for implant rehabilitation was too narrow to receive standard diameter implants and keep an inter-implant distance (IID) of 3 mm as recommended by accepted guidelines. A protocol of immediate implant placement and provisionalization involving 2 implants of Ø 3.5 mm was implemented; placement in the extraction sockets resulted in an IID of 1 mm. After 3 months of healing the final prosthesis was delivered; the patient has been followed for 10 years now. Surprisingly, the findings showed that the interimplant crest was maintained 1.40 mm coronal to the shoulder of the neck of the implants. Bone completely filled the space between the prosthetic concave abutments and the interproximal papilla was closing the embrasure. The literature reports only 2 experimental studies involving a 1 mm IID; both showed that this did not lead to the resorption of the interproximal bone.

Conclusions: Unexpectedly, the present case with an IID of 1 mm did not lead to the resorption of the interproximal bone after 10 years. It is speculated that the reason for that is due to the implants displaying an internal conical connection, the platform-switching feature, concave abutments and subcrestal placement. The fate of the interproximal crest of implants placed with an IID of 1 mm lacks scientific evidence. More studies are warranted to elucidate this question in order to propose the best implant treatment in cases displaying a limited mesio-distal space.

Purpose: The study aimed to examine the usefulness of a novel density measurement drill for evaluating cancellous bone density by examining the correlation between computed tomography (CT)-based Misch bone density classification and drilling torque value.

Methods: Bovine ribs were used as the drilling sites for implant placement. Multidetector CT (MDCT) was performed after contrast materials were attached to the drilling sites. CT value within the region of interest (ROI) on MDCT scan was measured and classified according to the Misch classification (D1 to D5). Drilling torque value was measured using a novel measurement drill. Next, histomorphometric analysis of the drilling site was performed to assess bone density, expressed as percentage of bone area within ROI.

Results: MDCT showed the presence of D2 (n = 87), D3 (n = 92), D4 (n = 133), and D5 (n = 52) at the measurement sites, however, no sites were classified as D1. The drilling torque values were 11.2 ± 3.2 Ncm for D2, 7.8 ± 3.3 Ncm for D3, and 3.0 ± 1.2 Ncm for D4, and 1.4 ± 0.6 Ncm for D5, with significant differences. A positive correlation was observed between CT value and drilling torque value (r = 0.99). Histomorphometric analysis revealed a positive correlation between drilling torque value and bone area ratio (r = 0.97).

Conclusions: The results of this limited study demonstrated the usefulness of the direct and objective cancellous bone density evaluation method using a novel measurement drill. This evaluation method will be informative for subsequent treatment decisions.

Purpose: The study assessed the clinical outcomes following treatment of peri-implant mucositis using Er:YAG laser or an ultrasonic device over six months. Patients' experience of pain, aesthetics, and Quality of life were further assessed.

Methods: One dental implant, per included patient, diagnosed with peri-implant mucositis underwent treatment with an Er:YAG laser (test) or an ultrasonic scaler (control) randomly. Treatments were performed at baseline and months three and six. At each session, oral hygiene was instructed after plaque registration, and the patient was guided in proper cleaning technique using a toothbrush and interproximal aids as needed. Full mouth bleeding on probing (FMBoP), full mouth plaque score (FMPS), implant bleeding on probing (BoP), implant mean graded bleeding (mBI), implant probing pocket depts (PPD), implant suppuration and bone levels were assessed. Oral health-related Quality of life (OHQoL) and visual analog scales (VAS), which reflect aesthetic satisfaction and pain of the treatment, were also evaluated.

Results: Forty-six patients were included. FMBoP was significantly reduced from 30.1 to 21.5% (test) (p < 0.001) respectively from 35.0% to 30% (control) (p < 0.01). FMPS showed significant reduction from 61.5 to 32.7% (test) (p < 0.001) and from 58.7 to 39.1% (control) (p < 0.001). At the implant BoP reduced from 89.0 to 55.7% (test) (p < 0.001) respectively from 94.9 to 63.7% (control) (p < 0.001). mBI was reduced from 1.3 to 0.6 (test) (p < 0.01) and from 1.9 to 0.8 (control) (p < 0.001). Distribution of "no bleeding" increased from 13 to 61% (test) (p < 0.05) and from 0 to 35% (control) (p < 0.05). At month three, statistically significant intergroup differences were shown for PPD ≥ 4 mm with 43.5% (test) respectively 73.9% (control) (p < 0.05). At month six, statistically significant intergroup differences, were shown for FMBoP 21.5% (test) respectively 30% (control) (p < 0.05) and for plaque score at the implant 4.0% (test) respectively 26% (control) (p < 0.05). Less pain was reported in the laser group at three days 0.08 (test) respectively 0.2 (control) (p < 0.05).

Conclusions: Treatment of peri-implant mucositis was effective regardless of whether the treatment was performed with an Er:YAG laser or an ultrasonic scaler. Fewer diseased sites were diagnosed at six months following laser treatment.

Trial registration: Registered at www.

Clinicaltrials: gov : study no, NCT05772299.

Purpose: This systematic review aims to assess the performance, methodological quality and reporting transparency in prediction models for the dental implant's complications and survival rates.

Methods: A literature search was conducted in PubMed, Web of Science, and Embase databases. Peer-reviewed studies that developed prediction models for dental implant's complications and survival rate were included. Two reviewers independently evaluated the risk of bias and reporting quality using the PROBAST and TRIPOD guidelines. The performance of the models were also compared in this study. The review followed the PRISMA guidelines and was registered with PROSPERO (CRD42019122274).

Results: The initial screening yielded 1769 publications, from which 14 studies featuring 43 models were selected. Four of the 14 studies predicted peri-implantitis as the most common outcome. Three studies predicted the marginal bone loss, two predicted suppuration of peri-implant tissue. The remaining five models predicted the implant loss, osseointergration or other complication. Common predictors included implant position, length, patient age, and a history of periodontitis. Sixteen models showed good to excellent discrimination (AUROC >0.8), but only three had undergone external validation. A significant number of models lacked model presentation. Most studies had a high or unclear risk of bias, primarily due to methodological limitation. The included studies conformed to 18-27 TRIPOD checklist items.

Conclusions: The current prediction models for dental implant complications and survival rate have limited methodological quality and external validity. There is a need for enhanced reliability, generalizability, and clinical applicability in future models.

Objective: This study aimed at investigating implant survival rate and marginal bone loss (MBL) around extra-short implants. The impact of the loading protocol and of the use of an intermediate abutment was also evaluated, to explore possible differences in terms of the outcome measures.

Materials and methods: Patients with single or multiple mandibular or maxillary posterior edentulism rehabilitated using extra-short 5-6 mm long implants were included. Different prosthetic protocols were used. Clinical and radiological follow-up was 5 years. The outcomes measures were implant survival and MBL.

Results: The analysis included 56 implants placed in 34 adults (12 males and 22 females; mean age 60 years, SD 11). Six implants failed during a median follow-up of 5 years and 4 of them were recorded in one patient at 2-year follow-up. The 5-year implant survival was 89% overall (87% in conventional and 94% in immediate loading). At univariate analysis, during follow-up immediate loading was associated with higher MBL (mean variation 0.21 mm, 95%CI 0.01 to 0.40; p = 0.02), while intermediate abutment was associated with lower MBL (mean variation -0.23 mm, 95%CI -0.39 to -0.09; p = 0.003). Multivariable analysis confirmed that immediate loading was associated with higher MBL.

Conclusion: Within its limitations, this study showed that extra-short implants under immediate loading conditions can be a reliable solution. The application of horizontal and vertical platform switching with the use of intermediate abutments seems to be able to contribute to the reduction of MBL.

Purpose: SLM 3D printing technology is one of the most widely used implant-making technologies. However, the surfaces of the implants are relatively rough, and bacteria can easily adhere to them; increasing the risk of postoperative infection. Therefore, we prepared a near-infrared photoresponsive nano-TiO₂ coating on the surface of an SLM 3D-printed titanium alloy sheet (Ti6Al4V) via a hydrothermal method to evaluate its antibacterial properties and biocompatibility.

Methods: Using SLM technology, titanium alloy sheets were 3D printed, and a nano-TiO₂ coating was prepared on its surface via a hydrothermal method to obtain Ti6Al4V@TiO₂. The surface morphology, physicochemical properties, and photothermal response of the samples were observed. The Ti6Al4V groups and Ti6Al4V@TiO₂ groups were cocultured with S. aureus and E. coli and exposed to 808 nm NIR light (0.8 W/cm²) and viable plate count experiments and live/dead bacterial staining were used to assess their in vitro antibacterial properties.

Results: The hydrophilicity of the nano-TiO₂ coating sample significantly improved and the sample exhibited an excellent photothermal response. The temperature reached 46.9± 0.32 °C after 15 min of irradiation with 808 nm NIR light (0.8 W/cm²). The Ti6Al4V group showed significant antibacterial properties after irradiation with 808 nm NIR light, and the Ti6Al4V@TiO₂ group also had partial antibacterial ability without irradiation. After irradiation with 808 nm NIR light, the Ti6Al4V@TiO₂ group showed the strongest antibacterial properties, reaching 90.11± 2.20% and 90.60± 1.08% against S. aureus and E. coli, respectively.

Conclusions: A nano-TiO₂ coating prepared via a hydrothermal method produced synergistic antibacterial effects after NIR light irradiation.

Purpose: In this randomized clinical trial, we examined the incorporation of nanogold particles into polymethyl methacrylate denture bases and compared these modified bases with conventional ones in mandibular implant-retained overdentures, focusing on microbiological growth and adhesion characteristics.

Methods: In this study, twenty-two male patients who were completely edentulous participated in a rehabilitation program involving mandibular overdentures retained by two dental implants placed in the canine area. The subjects were categorized into two equal groups, each comprising eleven patients. Group I received mandibular overdentures fabricated from conventional acrylic denture bases, whereas Group II received mandibular overdentures with bases that had undergone nanogold treatment. Microbial growth and colonization were evaluated around the implant's necks and the fitting surface of each patient's mandibular dentures. Three types of bacteria were studied: Candida albicans, Escherichia coli, and Streptococcus mutans. The mean difference in the counts of bacteria before the denture was inserted and after two, four, and six months has been calculated and analyzed statistically.

Results: Regarding colony count (log 10 CFUs/mmL), there was a significant difference between the research groups. Group II had significantly lower values measured at 2, 4, and 6 months for Candida albicans, Escherichia coli, and Streptococcus mutans, respectively, than group I.

Conclusion: The addition of gold nanoparticles to PMMA denture bases was of greater benefit in inhibiting microbial growth than conventional acrylic resin bases.