Could Dental Material Reuse Play a Significant Role in Preservation of Raw Materials, Water, Energy, and Costs? Microbiological Analysis of New versus Reused Healing Abutments: An In Vitro Study

AIM

The objective of this in vitro study was to compare reused and sterilized versus new healing abutments to assess whether a decontamination and sterilization process performed on resued healing abutments was sufficient to remove residual proteins. The two groups were comparable with respect to patient safety.

MATERIALS AND METHODS

During the period from September 2022 to October 2023, healing abutment screws were selected and divided into two groups according to whether they were new or previously used in patients. The samples were subjected to a decontamination and sterilization protocol, and results from sample sterility evaluation and assessment of surface protein levels were recorded.

RESULTS

The obtained results revealed a significant difference in the OD562 nm values between new and reused healing abutment samples. The assay demonstrates how treated healing abutments were still contaminated by residual proteins.

CONCLUSION

Within the limitations of the present study, although from an infectious point of view sterilization results in the total eradication of pathogens, surface proteins remain on reused healing abutments.

Full Arch Implant-Prosthetic Rehabilitation in Patients with Cardiovascular Diseases: A 7-Year Follow-Up Prospective Single Cohort Study

Aim: The rising average age increases edentulous cases, demanding more implant-prosthetic rehabilitation, with cardiovascular diseases being significant factors. This study compared healthy patients (CG = Control Group) and those with cardiovascular disease (TG = Test Group) for implant survival, Marginal Bone Loss (MBL), peri-implant tissue level parameters as Periodontal Screening and Recording (PSR), Plaque Index (PI), Bleeding on Probing (BoP) Peri-implant Probing Depth (PPD), and surgical complications. Smoking impact on both groups and medication influence in the TG were secondary outcomes. Patients underwent full-arch implant prosthetic rehabilitation. Methods: Implant survival rate, MBL, and surgical complications were recorded during the monitoring period (7 years), while peri-implant parameters were assessed at the end of the observational time. A total of 26 and 28 CG and TG patients were recruited, respectively. Results: A total of 128 implants were placed in CG, while 142 in the TG. Implant survival and MBL showed no significant differences (p > 0.05). Nevertheless, peri-implant parameters were more unfavorable in TG. The only significant surgical complication was higher bleeding rates in the TG (p < 0.05). Conclusions: Cardiovascular patients showed similar implant survival and MBL but had adverse peri-implant parameters and increased bleeding rates. Higher smoking levels may relate to unfavorable implant outcomes. Further investigation is needed on drug impact with larger samples.

Immediate Loaded Full-Arch Mandibular Rehabilitations in Younger vs. Elderly Patients: A Comparative Retrospective Study with 7-Year Follow-Up

The aim of this comparative retrospective clinical study was to assess the effect of age on immediate loaded full-arch mandibular rehabilitation in younger vs. elderly patients. Patients with an age between 45 and 60 years (younger group, YG) or with an age more or equal to 75 years (older group, OG), requiring a mandibular full-arch rehabilitation were scheduled for the present study. Implant and prosthetic failure, biological and prosthetic complications, and peri-implant marginal bone level changes were recorded until a 7-year follow-up. Sixty-six patients were included in the study; a total of 264 implants were placed and, in total, 66 "all-on-four" rehabilitations were delivered. In total, 33 patients were scheduled in the YG and 33 patients in the OG. At the 7-year follow-up, an overall implant failure rate of 1.14% was reported. Moreover, at the 7-year radiographic evaluation, peri-implant crestal bone loss averaged 1.12 ± 0.91 mm for the YG and 1.04 ± 1.01 mm for the OG. No statistically significant differences were found between the YG and OG except for the rate of peri-implantitis, which was statistically higher in the YG. The present study reported that immediate fixed mandibular full-arch rehabilitation is a viable procedure in elderly people of equal or more than 75 years of age.

Marginal Bone Loss Compared in Internal and External Implant Connections: Retrospective Clinical Study at 6-Years Follow-Up

The aim of this study was to assess and compare the marginal bone loss between two different categories of implants (Winsix, Biosafin, Ancona, Italy) having the same diameter and belonging to the Torque Type^® (TT^®) line, in the internal hexagon version (TTi, Group A) and in the external hexagon configuration (TTx, Group B). Patients with one or more straight implants (insertion parallel to the occlusal plane) in the molar and premolar regions in association with tooth extraction at least 4 months prior to implant insertion, who have a fixture diameter of 3.8 mm, who followed up for at least 6 years, and whose radiographic records were available were enrolled in this study. Depending on implant connections (externally or internally), the sample was divided into groups A and B. For externally connected implants (66), the marginal resorption was 1.1 ± 0.17 mm. The subgroup of single and bridge implants showed no statistically significant differences with a marginal bone resorption of 1.07 ± 0.15 mm and 1.1 ± 0.17 mm, respectively. Internally connected implants (69) showed an overall marginal resorption of 0.91 ± 0.17 mm, while the subgroup of single and bridge implants showed resorption of 0.90 ± 0.19 mm and 0.90 ± 0.17 mm, respectively, with no statistically significant differences. According to the obtained results, internally connected implants showed less marginal bone resorption than externally connected implants.

Full Arch Implant-Prosthetic Rehabilitation in Patients with Type I Diabetes Mellitus: Retrospective Clinical Study with 10 Year Follow-Up

The aim of this retrospective clinical study was to evaluate and compare implant survival, marginal bone loss, and clinical and prosthetic complications in healthy patients and patients with type I diabetes undergoing full arch implant-prosthetic rehabilitation. A total of 47 patients needing total fixed rehabilitation of one or both arches were enrolled for this study. Based on the absence of any systemic diseases (Group A) or the presence of type I diabetes (Group B), the sample was divided into two groups. According to the grade of bone atrophy in the posterior region, patients received full arch rehabilitation (of one or both jaws) with 6 axial implants or, if the residual posterior bone height was insufficient, All-on-Four rehabilitation and a total 236 dental implants were placed. Follow-up visits were performed 1 week after surgery, at 3 and 6 months and then once a year for the next 10 years. No statistically significant differences between groups were recorded about implant survival rates, marginal bone loss, or clinical and prosthetic complications. However, concerning complications, post-surgical bleeding and wound infection were recorded in Group A more than in Group B. In cases of compensated diabetes compensation, implant placement could be considered a safe procedure.

Implant rehabilitation of edentulous jaws with predominantly monolithic zirconia compared to metal-acrylic prostheses: a 2-year retrospective clinical study

Limited data are available on the clinical outcomes of patients with edentulism treated with predominantly monolithic zirconia fixed complete dentures (FCDs) compared to traditional restoration materials. The purpose of this study was to analyze the differences in terms of complications and failures of definitive full-arch implant rehabilitations made in metal-acrylic versus those made in monolithic zirconia with porcelain veneering limited to non-functional areas. This retrospective clinical study included 50 patients treated between January 2015 and December 2018, with 222 implants inserted in fifty edentulous jaws. All patients were treated with immediately loaded full-arch fixed prostheses (22 maxillary; 28 mandibular) each supported by four to six implants (two/four axial, two distally tilted). All 25 zirconia prostheses were predominantly monolithic with ceramic veneering limited to non-functional areas. The primary outcome measures were prosthetic success of the definitive restoration and implant survival. The secondary outcome measures were full mouth plaque score, full mouth bleeding score, peri-implant probing depths and periimplant keratinized tissue. All implants and prostheses analyzed had a minimum of 2 years of followup. No chipping of the veneered facial porcelain or other technical complication was observed over the study period achieving a prosthesis survival and success rate of 100%. No implants were lost, achieving a 100% survival rate. Bleeding on probing was positive in 33% and 13% of probing sites for metal-acrylic prosthesis and zirconia prosthesis, respectively (p = 0.0445). Plaque index was positive in 76% and 53% of probing sites for metal-acrylic prosthesis and zirconia prosthesis, respectively (p = 0.0491). Mean probing depth was 1.74mm (SD 0.89mm) for the 106 implants supporting metal-acrylic prosthesis and 1.52mm (SD 0.63mm) for the 116 implants supporting zirconia prosthesis (p=0.0412). No other statistically significant differences were found between the two groups. The results of this retrospective evaluation showed that predominantly monolithic zirconia is a feasible alternative to the conventional metal framework acrylic for full arch implant-supported prosthesis. The restauration material did not influence the failure rate and complication risk of both prosthesis and implants.

A simplified digital workflow for the prosthetic finishing of implant rehabilitations: a case report

The aim of this article is to describe how, during the provisional and definitive prosthetic phases, using new digital technologies, it is possible to improve the ergonomics of the prosthetist's work and reduce the discomfort of patients, subjecting them to the fewest possible appointments at the dentist. The proposal of a full digital protocol, described by the following case report, for the realization of a definitive prosthetic rehabilitation supported by a reduced number of implants, in fact, allows to considerably reduce the number of appointments and reduce any bias. A 67-year-old male patient presents for the first visit to the Department of Dentistry of the San Raffaele Hospital, wearing a removable upper prosthesis and with the request to heal the aesthetic and functional situation through prosthetics fixed. An initial panoramic radiograph was performed, intra and extra oral photos were taken and also intraoral impressions. A stereo-lithographic models are obtained from intraoral scans, and two total prostheses, upper and lower, were packaged for the provisional post-surgical phase was performed. In accordance with the All-on-4 method 8 implant fixtures were placed. For the final prosthetic phase, the patient underwent only two operative sessions. In the first session, scans were taken with the provisionals in situ, of the patient's mucous membranes and with the Scan-abutments in place. In the second session using specific CADSoftware the matching of the STL files of the three scans were created, the opposing arches of the patient were related on a digital articulator, and the milled titanium bars were immediately constructed and finished with the resin. Finally, the definitive prostheses were delivered to the patient without any other test. Digital technology has allowed a clear reduction in working times and costs and has allowed the reduction of stress for patients who undergo invasive and extensive treatments to recover aesthetics and function, and for clinicians who must manage complex cases with fewer appointments possible.

Management of the delicate phase of the temporary crown: an in vitro study

The fundamental moment of prosthetic rehabilitation is the "temporary". Although the meaning of the term diminishes its importance, the provisional has fundamental biological, aesthetic and functional functions. The oral cavity must maintain an adequate level of oral hygiene to carry out this delicate phase in the best possible way; a result achieved only with the collaboration of the prosthetic dentist with the hygienist and the patient, as if they were a biological system in motion. The different methods of hygiene are effective in maintaining a good level of oral health; but they could, if too aggressive, affect the prosthetic restoration. Our objective in vitro is to understand, after applying a known bacterial load, which hygiene method is the most effective in removing bacterial biofilm but at the same time is less aggressive towards resinous material.

Role of induced pluripotent stem cells (IPSCS) in bone tissue regeneration in dentistry: a narrative review

Several conditions as trauma, cancer surgical resection, fractures, congenital malformations and periodontitis could bring alveolar bone defects. To avoid more invasive and less predictable regenerative procedures, Stem cells of different origins as pluripotent Embryonic Stem Cells (ESCs), undifferentiated multipotent Mesenchymal Stem Cells (MSCs) and Induced Pluripotent Stem Cells (iPSCs) were proposed as possible alternative. IPSCs have potential for proliferation and differentiate into all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. According with their ability to involve in several cells type, Induced Pluripotent Stem Cells (iPSCs) could be proposed as alternative in regeneration either of mineralized tooth components or supporting tissue. The aim of this brief review is to describe clinical applications of Induced Pluripotent Stem Cells (iPSCs) in oral bone regeneration to employ their use in tissue regeneration in dentistry.

The 'All-on-four' protocol in HIV-positive patients: A prospective, longitudinal 7-year clinical study

PURPOSE

This prospective study aims to evaluate the clinical outcomes of 'All-on-four' rehabilitations in controlled human immunodeficiency virus (HIV)-positive patients.

MATERIALS AND METHODS

Edentulous patients requiring an implant prosthetic restoration of one or both jaws were enrolled in the present study. Each patient received at least one fixed full-arch prosthesis. Four implants, immediately loaded, were placed in each jaw using the 'All-on-four' protocol. Marginal bone loss, implant and prosthetic failure, biological and mechanical complications, and serological levels (CD4 cell count, CD4/CD8 ratio, and HIV viral load) were recorded up to 7-year follow-up.

RESULTS

A total of 116 implants were placed in 24 patients, and 29 rehabilitations based on the 'All-on-four' concept were achieved. Implant failures were registered in four patients (10 of 116 implants), and the implant survival rate was 91.37%. At the 7-year radiographic evaluation, peri-implant crestal bone loss averaged 1.91 ± 1.3 mm for upright maxillary implants (n = 30 implants) and 1.79 ± 1.28 mm for tilted maxillary implants (n = 30 implants). In the mandible, mean peri-implant crestal bone loss was 1.54 ± 1.27 mm for upright implants (n = 28) and 1.5 ± 1.3 mm for tilted implants (n = 28). No statistically significant correlation was found between serological parameters and marginal bone levels at 6 months, or through 7 years of annual follow-up (P > 0.05). A statistically significant linear correlation (P < 0.001) was found between early implant failure and HIV viral load. The CD4/CD8 ratio was significantly correlated with late implant failure (P = 0.009).

CONCLUSIONS

Within the limitations of this prospective 7-year longitudinal study, HIV-positive patients with a stable immune system can be candidates for the 'All-on-four' treatment concept.

New measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation

A new measurement of the cosmic-ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-Earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a tenfold improvement in statistics with respect to all previously published data. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g., dark matter particle annihilations.

Assessment of the QoL in Italian menopausal women: comparison between HRT users and non-users

OBJECTIVES

The aim of this cross-sectional study was to describe QoL in a large sample of women attending menopause centres and compare untreated postmenopausal women and matched HRT users by employing the Women's Health Questionnaire (WHQ) and two generic instruments, the SF-36 and the EQ-5D.

METHODS

Overall, 2906 women were recruited by 64 menopause centres throughout Italy, of whom 2160 filled in the questionnaire (1093 on HRT and 1067 not on HRT; response rate: 74%).

RESULTS

HRT users tended to be younger, healthier and with shorter menopause duration as opposed to non users, while no major socio-economic differences were present. At multivariate analysis, the presence of chronic diseases, low socio-economic status and living in Southern Italy represented the most important predictors of poor QoL. Furthermore, HRT users showed a lower probability of reporting problems in usual activities and pain/discomfort (EQ-5D), role limitations due to emotional problems (SF-36) and anxiety/fears (WHQ). HRT users also showed highly significant better outcomes in those areas that are more directly attributable to hormonal changes of mid age, namely vasomotor symptoms and sexual problems.

CONCLUSIONS

Although QoL is mainly influenced by socio-economic and cultural factors, HRT has the potential for improving not only symptoms, but also more general aspects of physical and psychological well-being of symptomatic postmenopausal women.

Validation of Italian version of the Women's Health Questionnaire: assessment of quality of life of women from the general population and those attending menopause centers

OBJECTIVES

The Women's Health Questionnaire has been developed and validated in Anglo-Saxon and Swedish populations. The purpose of this study was to evaluate the Italian version of the questionnaire to determine whether cross-cultural differences exist in the perception of quality of life, and to use it to compare the quality of life in women attending menopause centers with that of women in the general population.

METHODS

An Italian version of the Women's Health Questionnaire (WHQ) was produced, using the forward-backward translation method to ensure conceptual equivalence, and approved by the originator. Women were recruited by random selection from the general population and from menopause centers, those taking hormone replacement therapy being ineligible. The questionnaire was completed anonymously at home and mailed to the co-ordinating center. Psychometric evaluation included tests of item convergent and discriminant validity, internal-consistency reliability, test-retest reliability, construct validity and the discriminative properties of the questionnaire.

RESULTS

The completeness of the data was good, with missing-value rates consistently low for most items. Item-scale correlations, used to evaluate internal consistency, were also good and the scaling success rate, used to measure item discriminant validity, was high for all scales. Scale scores were reliable for seven out of nine scales and test-retest reliability was excellent. There were few significant differences between the two populations of women in most of the WHQ areas. A comparison of Italian data with published data on English women showed great similarity.

CONCLUSION

The Italian version of the WHO is valid and reproducible. The subjective perception of the menopause and its related problems is similar in geographically and culturally different populations.