Search Results (11)

This study compares the effect of different handpieces (turbine, high-speed electric handpiece and piezoelectric device) on surface roughness of enamel and dentin when using diamond-coated working tips and burs of the same grit size. The experiment was conducted on 15 extracted first molars from patients aged 45 to 60 years. The occlusal portion was removed using a diamond-coated water wheel and then refined with a 120–130 μm grit bur in order to obtain a flat surface with an adequate exposition of the dentin core. Each surface was divided into three portions and every portion was finished with one of the three tested instruments. The rotary burs and piezoelectric tips had the same grit size (60 μm), and the load on handpiece during preparation never exceeded 150 g. Roughness parameters (Ra, Rsk, Rku) were recorded with a profilometer, and a SEM analysis of treated surfaces and working tips was conducted. Ra and Rsk differed significantly between enamel and dentin only after using turbine (p = 0.004 and p = 0.007, respectively). No significant differences were observed in Ra, Rsk and Rku between enamel and dentin when using a high-speed electric handpiece or piezoelectric device. The turbine produced higher Ra and Rsk values on dentin than the other devices, while no significant differences were found between piezoelectric handpiece and high-speed electric contra-angle on both substrates. Summarizing, the findings of the present study demonstrated that turbine generated rougher surfaces on dentin compared to the other handpieces. Moreover, the turbine produced more asymmetrical surface profiles on both enamel and dentin. However, it should be considered that these differences in roughness (Ra) were within the range of 0.25–0.30 μm: it is still unclear if these variations, although statistically significant, will influence final clinical outcomes. Full article

Although the application of ultrasounds in endodontic surgery allows for effective debridement of the root canal, incorrect device setting or inefficient tips seem to generate cracks during root-end retropreparation. The primary aim of this in vitro study was to establish the presence, or absence, of a correlation between ultrasonic root-end preparation and the formation of cracks. The present study was conducted on human teeth, extracted for periodontal reasons. After root canal treatment, roots were resected 3 mm from the anatomical apex by using a high-speed handpiece and carbide burs. The resected teeth were retroprepared by using an ultrasonic tip (R1D, Piezomed, W&H, Bürmoos, Austria), setting the piezoelectric device at maximum power available for the tip. Time required for the retropreparation was recorded. Before and after retropreparation, all roots were photographed under a stereomicroscope and analyzed by two different operators to evaluate: (a) the presence and extension of dentinal cracks and (b) the morphology of root-end preparation. Finally, piezoelectric tips were analyzed by scanning electron microscopy (SEM) to evaluate morphologic changes after use. A total of 43 single roots (33 with one root canal, 10 with two root canals) were treated. Average preparation time was 1 minute and 54 seconds. None of the roots without initial cracks developed new cracks after retropreparation. Quality of the preparation margins was fairly equal among the prepared specimens. None of the piezoelectric tips broke during instrumentation, and SEM analysis showed minimal surface wear of the tips after performing 11 retropreparations. Within the limits of the present study, the tested piezoelectric system does not seem to represent a major cause for root crack formation. Pre-existing cracks may expand after ultrasound root-end preparation. Full article

Sinus membrane perforation is the most frequent intraoperative complication occurring during maxillary sinus floor elevation. Although numerous techniques for perforation management are present, grafting material dissemination may still occur, representing a potential trigger factor leading to acute or chronic sinusitis. This case report describes two cases of xenogeneic bone substitute in gel form accidentally dispersed into the sinus cavity during maxillary sinus floor elevation with a transcrestal approach. In both cases, immediately postoperative radiographic imaging showed an important amount of gel graft dislodged into the sinus cavity as a consequence of hidden perforations that remained undetected during surgery. Patients were monitored for 6 months after surgery and reported no signs or symptoms related to possible sinus disease. Control radiographs showed no sinus membrane hypertrophy and/or presence of residual disseminated gel, confirming complete clearance of the accidentally dispersed graft through the ostiomeatal complex. In order to minimize postoperative complications, bone substitutes in gel form could represent an interesting alternative to granular grafts for their easier clearance from the maxillary sinus cavity in case of accidental dissemination during sinus augmentation procedures. Full article

Background: The purpose of this study was to compare clinical results of two different horizontal ridge augmentation techniques: guided bone regeneration with sticky bone (SB) and the bone-shell technique (BS). Methods: Records of patients who underwent horizontal ridge augmentation with SB (test) and BS (control) were screened for inclusion. Pre-operative and 6-month post-operative ridge widths were measured on cone beam computer tomography (CBCT) and compared. Post-operative complications and implant survival rate were recorded. Results: Eighty consecutive patients were included in the present study. Post-operative complications (flap dehiscence, and graft infection) occurred in ten patients, who dropped out from the study (12.5% complication rate). Stepwise multivariate logistic regression analysis showed a significant inverse correlation between the occurrence of post-operative complications and ridge width (p = 0.025). Seventy patients (35 test; 35 control) with a total of 127 implants were included in the final analysis. Mean ridge width gain was 3.7 ± 1.2 mm in the test and 3.7 ± 1.1 mm in the control group, with no significant difference between the two groups. No implant failure was recorded, with a mean follow-up of 42.7 ± 16.0 months after functional loading. Conclusions: SB and BS showed comparable clinical outcomes in horizontal ridge augmentation, resulting in sufficient crestal width increase to allow implant placement in an adequate bone envelope. Full article

The present study aims to investigate clinical and patient-centered outcomes after the implant-supported rehabilitation of narrow ridges using a novel wedge-shaped implant. Forty-four patients were treated with the insertion of 59 tissue-level wedge implants (1.8 mm bucco-lingual width) in horizontally atrophic ridges (mean bone width 3.8 ± 0.4 mm). The main outcome measures were: implant stability quotient (ISQ), marginal bone loss (MBL) and patient morbidity. Fifty-eight implants were functioning satisfactorily after one year of loading (98.3% survival rate). ISQ values measured in the mesio-distal direction resulted significantly higher than those in the bucco-lingual direction at all time points (p < 0.001). Both mesio-distal and bucco-lingual ISQ values at 6-month follow-up resulted significantly higher than at 4-month follow-up (p < 0.001 for both). Mean MBL was 0.38 ± 0.48 mm at prosthesis delivery (6 months after implant insertion) and 0.60 ± 0.52 mm after one year of functional loading. The majority of patients reported slight discomfort related to the surgical procedure. Postoperative pain score was classified as mild pain on the day of surgery and the first postoperative day and no pain over the following five days. Within the limitations of the present study, the device investigated showed low morbidity and positive short-term clinical results in narrow ridges treatment. Full article

Piezoelectric devices are widely used in oral surgical procedures, including implant site preparation. However, little is known about the influence of working movement on temperature elevation in bone. The aim of this study was to assess the effects of two different working cycles on temperature elevation during piezoelectric implant site preparation. Sixty osteotomies at a depth of 10 mm were performed on bone blocks of bovine ribs using a piezoelectric tip with external irrigation (IM1s, Mectron Medical Technology, Carasco, Italy). A mechanical positioning device was used to guarantee reproducible working and measuring conditions. Two different working cycles, of 4 and 6 s, respectively, were tested, including both longitudinal and rotational movements. Temperature was recorded in real time with a fiber optic thermometer and applied pressure was maintained under 150 g. For each test, the highest recorded temperature (T_max) and the mean temperature recorded from 30 s before to 30 s after the highest recorded temperature (T_±30) were extrapolated. Tests duration was also recorded. Both T_max and T_±30 were significantly higher in the ‘6 s cycles’ group than the ‘4 s cycles’ group (42.44 ± 7.3 °C vs. 37.24 ± 4.6 °C, p = 0.002; 37.24 ± 4.6 °C vs. 33.30 ± 3.3 °C, p = 0.003). Test duration was also significantly higher using 6 s cycles compared to 4 s cycles (143.17 ± 29.4 s vs. 119.80 ± 36.4 s, p = 0.002). The results of this study indicate that working cycles of 4 s effectively reduce heat generation and working time during piezoelectric implant site preparation. Full article

The aim of this retrospective case series was to evaluate the clinical efficacy of nanohydroxyapatite powder (NHA) in combination with polylactic acid/polyglycolic acid copolymer (PLGA) as a bone replacement graft in the surgical treatment of intrabony periodontal defects. Medical charts were screened following inclusion and exclusion criteria. Periodontal parameters and periapical radiographs taken before surgery and at 12-month follow-up were collected. Intra-group comparisons were performed using a two-tailed Wilcoxon signed-rank test. Twenty-five patients (13 males, 12 females, mean age 55.1 ± 10.5 years) were included in the final analysis. Mean probing depth (PD) and clinical attachment level (CAL) at baseline were 8.32 ± 1.41 mm and 9.96 ± 1.69 mm, respectively. Twelve months after surgery, mean PD was 4.04 ± 0.84 mm and CAL was 6.24 ± 1.71 mm. Both PD and CAL variations gave statistically significant results (p < 0.00001). The mean radiographic defect depth was 5.54 ± 1.55 mm and 1.48 ± 1.38 mm at baseline and at 12-month follow-up, respectively (p < 0.0001). This case series, with the limitations inherent in the study design, showed that the combination of NHA and PLGA, used as bone replacement graft in intrabony periodontal defects, may give significant improvements of periodontal parameters at 12-month follow-up. Full article

Early marginal bone loss (MBL) is a non-infective remodeling process of variable entity occurring within the first year after implant placement. It has a multifactorial etiology, being influenced by both surgical and prosthetic factors. Their impact remains a matter of debate, and controversial information is available, particularly regarding implants placed subcrestally. The present multicenter prospective clinical study aimed to correlate marginal bone loss around platform-switched implants with conical connection inserted subcrestally to general and local factors. Fifty-five patients were enrolled according to strict inclusion/exclusion criteria by four clinical centers. Single or multiple implants (AnyRidge, MegaGen, South Korea) were inserted in the posterior mandible with a one-stage protocol. Impressions were taken after two months of healing (T1), screwed metal-ceramic restorations were delivered three months after implant insertion (T2), and patients were recalled after six months (T3) and twelve months (T4) of prosthetic loading. Periapical radiographs were acquired at each time point. Bone levels were measured at each time point on both mesial and distal aspects of implants. Linear mixed models were fitted to the data to identify predictors associated with MBL. Fifty patients (25 male, 25 female; mean age 58.0 ± 12.8) with a total of 83 implants were included in the final analysis. The mean subcrestal position of the implant shoulder at baseline was 1.24 ± 0.57 mm, while at T4, it was 0.46 ± 0.59 mm under the bone level. Early marginal bone remodeling was significantly influenced by implant insertion depth and factors related to biological width establishment (vertical mucosal thickness, healing, and prosthetic abutment height). Deep implant insertion, thin peri-implant mucosa, and short abutments were associated with greater marginal bone loss up to six months after prosthetic loading. Peri-implant bone levels tended to stabilize after this time, and no further marginal bone resorption was recorded at twelve months after implant loading. Full article

Background: Macro- and micro-geometry are among the factors influencing implant stability and potentially determining loading protocol. The purpose of this study was to test a protocol for early loading by controlling implant stability with the selection of fixtures with different thread depth according to the bone density of the implant site. Materials and Methods: Patients needing implant therapy for fixed prosthetic rehabilitation were treated by inserting fixtures with four different thread diameters, selected based on clinical assessment of bone quality at placement (D1, D2, D3, and D4, according to Misch classification). Final insertion torque (IT) and implant stability quotient (ISQ) were recorded at baseline and ISQ measurements repeated after one, two, three, and four weeks. At the three-week measurement (four weeks after implant replacement), implants with ISQ > 70 Ncm were functionally loaded with provisional restorations. Marginal bone level was radiographically measured 12 months after implant insertion. Results: Fourteen patients were treated with the insertion of forty implants: Among them, 39 implants showing ISQ > 70 after 3 weeks of healing were loaded with provisional restoration. Mean IT value was 82.3 ± 33.2 Ncm and varied between the four different types of bone (107.2 ± 35.6 Ncm, 74.7 ± 14.0 Ncm, 76.5 ± 31.1 Ncm, and 55.2 ± 22.6 Ncm in D1, D2, D3, and D4 bone, respectively). Results showed significant differences except between D2 and D3 bone types. Mean ISQ at baseline was 79.3 ± 4.3 and values in D1, D2, D3, and D4 bone were 81.9 ± 2.0, 81.1 ± 1.0, 78.3 ± 3.7, and 73.2 ± 4.9, respectively. Results showed significant differences except between D1 and D2 bone types. IT and ISQ showed a significant positive correlation when analyzing the entire sample (p = 0.0002) and D4 bone type (p = 0.0008). The correlation between IT and ISQ was not significant when considering D1, D2, and D3 types (p = 0.28; p = 0.31; p = 0.16, respectively). ISQ values showed a slight drop at three weeks for D1, D2, and D3 bone while remaining almost unchanged in D4 bone. At 12-month follow-up, all implants (39 early loading, 1 conventional loading) had satisfactory function, showing an average marginal bone loss of 0.12 ± 0.12 mm, when compared to baseline levels. Conclusion: Matching implant macro-geometry to bone density can lead to adequate implant stability both in hard and soft bone. High primary stability and limited implant stability loss during the first month of healing could allow the application of early loading protocols with predictable clinical outcomes. Full article

Nowadays implant-prosthetic rehabilitations are one of the best solutions for rehabilitating our patients. These allow obtaining rehabilitations with optimal functional and aesthetic performances. Often patients, who undergo implant-prosthetic therapy, have the conditions of edentulias, single or multiple, that have been going on for some time. This, according to the literature, produces resorption of the alveolar bone, a process that is complicated in the posterior area of the upper arch by a pneumatization of the maxillary sinuses. The loss of vertical height, so that the implant fixtures can be inserted, requires a maneuver called maxillary sinus floor elevation. This procedure, now safely performed with piezoelectric instruments, allows increasing bone height through bone grafting. In this study, the tissue obtained from a patient, after 15 years from the intervention, was evaluated by histological and SEM analyses. The bone healing in the patient has led to a perfect integration between the patient’s bone and the fresh frozen allograft used, however still present and detectable after 15 years. Full article

Background: Bone substitutes, either from human (autografts and allografts) or animal (xenografts) sources, suffer from inherent drawbacks including limited availability or potential infectivity to name a few. In the last decade, synthetic biomaterials have emerged as a valid alternative for biomedical applications in the field of orthopedic and maxillofacial surgery. In particular, phosphate-based bone substitution materials have exhibited a high biocompatibility due to their chemical similitude with natural hydroxyapatite. Besides the nature of the biomaterial, its porous and interconnected architecture is essential for a correct osseointegration. This performance could be predicted with an extensive characterization of the biomaterial in vitro. Methods: In this study, we compared the biological, chemical, and structural features of four different commercially available bone substitutes derived from an animal or a synthetic source. To this end, µ-CT and SEM were used to describe the biomaterials structure. Both FTIR and EDS analyses were carried out to provide a chemical characterization. The results obtained by these techniques were correlated with cell adhesion and proliferation of the osteosarcoma MG-63 human cell line cultured in vitro. Results: The findings reported in this paper indicate a significant influence of both the nature and the structure of the biomaterials in cell adhesion and proliferation, which ultimately could affect the clinical performance of the biomaterials. Conclusions: The four commercially available bone substitutes investigated in this work significantly differed in terms of structural features, which ultimately influenced in vitro cell proliferation and may so affect the clinical performance of the biomaterials. Full article