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Histological evaluation of peri-implant soft tissues in immediately loaded implants featuring different implant-abutment connections: A preliminary study
Full text linkThe Influence of Platform Switching on the Biomechanical Aspects of the Implant-Abutment System. A Three Dimensional Finite Element Study
No full textObjective: to evaluate the biomechanical scenario of platform switching geometric implant-abutment configuration relative to standard configurations by means of finite element analysis.
Study Design: A 3D Finite Element Analysis (FEA) was performed on 3 different implant-abutment configurations: a 3.8 mm implant with a matching diameter abutment (Standard Control Design, SCD), a 5.5 mm implant
with matching diameter abutment (Wider Control Design, WCD), and a 5.5mm implant with a 3.8 mm abutment
(Experimental Design, ED). All the different experimental groups were discretized to over 60000 elements and
100000 nodes, and 130N vertical (axial) and 90N horizontal loads were applied on the coronal portion of the abutment. Von Mises stresses were evaluated and maximum and minimum values were acquired for each implantabutment configuration.
Results: The load-induced Von Mises stress (maximum to minumum ranges) on the implant ranged from 150
MPa to 58 Pa (SCD); 45 MPa to 55 Pa (WCD); 190 MPa to 64 Pa (ED). The Von Mises stress on the abutment
ranged from 150 MPa to 52 MPa (SCD); 70 MPa to 55 MPa (WCD), and 85 MPa to 42 MPa respectively (ED). The
maximum stresses transmitted from the implant-abutment system to the cortical and trabecular bone were 67 Pa
and 52 MPa (SCD); 54 Pa and 27 MPa (WCD); 64 Pa and 42 MPa (ED), respectively. When the implant body was
evaluated for stresses, a substantial decrease in their levels were observed at the threaded implant region due to
the diametral mismatch between implant and abutment for the ED configuration.
Conclusion: The platform switching configuration led to not only to a relative decrease in stress levels compared
to narrow and wide standard configurations, but also to a notable stress field shift from bone towards the implant
system, potentially resulting in lower crestal bone overloadin
The importance of immediately loaded immediate post-extractive implants in esthetical rehabilitation: case series.
No full textImmediate Restoration of Single Implants Placed Immediately After Tooth Extraction
No full textBACKGROUND:
Some of the original surgical protocols for implant surgery have been reassessed to satisfy the patient's continuously increasing expectation for shorter rehabilitation time, improved esthetics, and increased comfort. The aim of this study was to evaluate the 12-month clinical success of 18 single-tooth implants inserted immediately after tooth extraction and restored the same day with non-functional loading.
METHODS:
A total of 18 patients (12 women and six men), 22 to 60 years old, were enrolled in this study. Eighteen single implants were inserted in fresh extraction sockets and immediately restored with temporary abutments and crowns. All experimental sites showed an absence of fenestrations or dehiscences of the bone walls and a residual gap between implant surfaces and surrounding bone walls < or =2 mm. All temporary prostheses were positioned the same day of surgery and were not in occlusal contact with opposing arches. The comparison between the baseline and 12-month visits was performed with the Student t test for paired data (statistically significant at a level of alpha = 0.05).
RESULTS:
During the 12-month follow-up period, one fixture was removed 4 weeks after implant placement following an abscess. All remaining implants healed uneventfully with no complications and were assessed as stable and successful at the 12-month checkup. No technical complications such as screw loosening, resin fracture, or pain during chewing were registered during the 12-month period.
CONCLUSIONS:
Within the limits of the data from this study, it can be suggested that immediate placement and restoration of a single implant can be a valid and successful option of treatment in the case of single compromised teeth. Moreover, this treatment protocol eliminates the need for removable provisional restoration and seems to maintain the preexisting architecture of soft and hard tissues in most cases. Nonetheless, further prospective and long-term studies are required to obtain a better insight into the limitations of this protocol
Valutazione della topografia superficiale di impianti macchinati e sabbiati e mordenzati / Atomic force microscope for implant surface study
No full textScopo del lavoro Il presente studio analizza mediante l’uso di un microscopio a forza atomica (AFM) la ruvidità di superficie di impianti macchinati messi a confronto con impianti sabbiati e mordenzati per meglio comprendere le reali condizioni fisiche osservabili sulla superficie e che influenzano l’osteointegrazione. Materiali e metodi L’AFM ricostruisce l’immagine della superficie di un campione attraverso una scansione per punti di un raggi laser consentendo di ottenere una immagine tridimensionale della superficie analizzata. Sono state realizzate scansioni a 3, 30 e 60 mm; il tipo di matrice utilizzata è stato di 256x256 per un totale di 65.536 scansioni. Risultati e conclusioni La ruvidità media di superficie risulta apprezzabilmente differente tra le due superfici implantari analizzate a netto vantaggio degli impianti sabbiati e mordenzati, ma sono necessari ulteriori studi per definire le proprietà biologiche e biomeccaniche ideali.Aim In this study surface roughness of machined implants is compared to sandblasted-acid etched implants by atomic force microscope analysis in order to understand the real physical conditions that is possible to observe on surface and that influence osseointegration. AFM reconstructs the surface image of a sample by scanning per point through laser beam and achieving a three-dimensional image. A total of 3, 30 and 60 mm scans were made and a 256x256 matrix was used for a totals of 65536 scans. Results and conclusions Mean surface roughness is different between the two analyzed surfaces is in favour of sandblasted-acid etched implants. However further studies are needed to define ideal biological and biomechanical properties
Changes in microflora in dental plaque from cancer patients undergoing chemotherapy and the relationship of these changes with mucositis: a pilot study
Full text linkObjective: To assess changes in oral microflora in dental plaque from cancer patients within 7 days of the first course of chemotherapy, and the relationship of the changes with mucositis. Study Design: Thirty cancer patients, divided into a test group undergoing chemotherapy and a control group no undergoing chemotherapy, were enrolled in this pilot study. Oral microflora were cultured from three samples of dental plaque at t0 (before chemotherapy), t1 (1 day after chemotherapy) and t2 (7 days after chemotherapy). Single and crossed descriptive analyses were used to establish prevalence, and the χ2 test was used to establish the statistical significance of the differences observed in distributions (significance level: P<0.05). Results: In most patients (57%), oral microflora consisted mainly of Gram-positive cocci, while the remaining 43% of the bacterial flora also had periodontal-pathogenic species. No Porphyromonas gingivalis appeared in the test group. Actinobacillus was the least frequently found bacterium among periodontal pathogens in the test group, while Fusobacterium nucleatum was the most frequently found. No significant differences were found in quantitative bacterial changes between t0, t1 and t2 in either the test or control groups, or between the two groups. According to World Health Organization scores, oral mucositis developed in 10 patients (66.6%) in the test group. Conclusions: The results of this pilot study indicate that there were no changes in microflora in dental plaque in cancer patients within 7 days of the first course of chemotherapy. No correlations between oral mucositis and specific microorganisms were assessed
Oral health in a cohort of individuals on a plant-based diet: a pilot study
No full textINTRODUCTION:
Plant-based diets are associated with a lower: (i) body mass index, (ii) rates of death from ischemic heart disease, (iii) serum cholesterol, (iv) incidence of high blood pressure, (v) type II diabetes mellitus and cancer, with an overall longer life expectancy. However, little data concerning the oral health in individuals on a plant-based diet are available.
AIM:
The aim of the present study was to investigate the general and clinical oral health status in a cohort of adults who had been following a plant-based diet for a minimum of 24 months.
MATERIAL AND METHODS:
For this purpose, individuals were administered two questionnaires (a.Questionnaire investigating risk areas for oral diseases; b. Italian version of the Oral Health Impact Profile -14 (IOHIP-14)) by a dental hygienist and clinical examination of the oral cavity was carried out.
RESULTS:
Seventy-seven adult individuals were enrolled. On average, they followed a plant-based diet for the last four years, had four meals a day and brushed their teeth twice a day. Fruit was the most frequently consumed food at breakfast by 48 of the participants. Thirty-four responders did not drink beer or wine, 65 did not drink spirits, 57 avoided carbonated beverages and 62 (80.5%) did not consume any highly-sugared beverages. Different dental therapies in the previous three years were reported in 36 of the responders. Overall, answers "never and almost never" to the IOHIP-14 questionnaire were observed in 87% to 100% of the individuals. Multiple logistic regression analysis revealed that fresh fruit consumption at lunch had a protective effect against caries (p<0.05).
CONCLUSIONS:
In conclusion, this study showed that individuals on a plant-based diet have good overall oral health conditions. These features are in agreement with the behavior of these subjects towards an overall healthy life style
Valutazione della topografia superficiale di impianti macchinati e sabbiati e mordenzati
No full textNon previst
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