Spectroscopic insights into peri-implant mucositis and peri-implantitis: unveiling peri-implant crevicular fluid profiles using surface enhanced Raman scattering.

The precise identification and differentiation of peri-implant diseases, without the need for intrusive procedures, is crucial for the successful clinical treatment and overall durability of dental implants. This work introduces a novel approach that combines surface-enhanced Raman scattering (SERS) spectroscopy with advanced chemometrics to analyse peri-implant crevicular fluid (PICF) samples. The primary purpose is to offer an unbiased evaluation of implant health. A detailed investigation was performed on PICF samples obtained from a cohort of patients exhibiting different levels of peri-implant health, including those with healthy implants, implants impacted by peri-implantitis, and implants with peri-implant mucositis. The obtained SERS spectra were analysed using canonical-powered partial least squares (CPPLS) to identify unique chemical characteristics associated with each inflammatory state. Significantly, our research findings unveil the presence of a common inflammatory SERS spectral pattern in cases of peri-implantitis and peri-implant mucositis. Furthermore, the SERS-based scores obtained from CPPLS were combined with established clinical scores and subjected to a linear discriminant analysis (LDA) classifier. Repeated double cross-validation was used to validate the method's capacity to discriminate different implant conditions. The integrated approach showcased high sensitivity and specificity and an overall balanced accuracy of 92%, demonstrating its potential to serve as a non-invasive diagnostic tool for real-time implant monitoring and early detection of inflammatory conditions.

Inter and intra-operator reliability of Lekholm and Zarb classification and proposal of a novel radiomic data-driven clustering for qualitative assessment of edentulous alveolar ridges.

OBJECTIVES: The present study was conducted to evaluate the reproducibility of Lekholm and Zarb classification system (L&Z) for bone quality assessment of edentulous alveolar ridges and to investigate the potential of a data-driven approach for bone quality classification. MATERIALS AND METHODS: Twenty-six expert clinicians were asked to classify 110 CBCT cross-sections according to L&Z classification (T0). The same evaluation was repeated after one month with the images put in a different order (T1). Intra- and inter-examiner agreement analyses were performed using Cohen's kappa coefficient (CK) and Fleiss' kappa coefficient (FK), respectively. Additionally, radiomic features extraction was performed from 3D edentulous ridge blocks derived from the same 110 CBCTs, and unsupervised clustering using 3 different clustering methods was used to identify patterns in the obtained data. RESULTS: Intra-examiner agreement between T0 and T1 was weak (CK 0.515). Inter-examiner agreement at both time points was minimal (FK at T0: 0.273; FK at T1: 0.243). The three different unsupervised clustering methods based on radiomic features aggregated the 110 CBCTs in three groups in the same way. CONCLUSIONS: The results showed low agreement among clinicians when using L&Z classification, indicating that the system may not be as reliable as previously thought. The present study suggests the possible application of a reproducible data-driven approach based on radiomics for the classification of edentulous alveolar ridges, with potential implications for improving clinical outcomes. Further research is needed to determine the clinical significance of these findings and to develop more standardized and accurate methods for assessing bone quality of edentulous alveolar ridges.

IMPLANT SURVIVAL IN RENAL-TRANSPLANTED PATIENTS: A PROSPECTIVE LONG-TERM STUDY.

The present study aims to assess the feasibility of implant rehabilitation in kidney-transplanted patients. Patients with kidney transplantation included in periodontal supportive care and at least one year of dialysis with mono- or partial edentulism were eligible for this study. Histomorphometric evaluation of the harvested bone was matched with radiological bone assessment. Implant stability was also monitored with RFA and ITV. Fixed cemented prostheses have been delivered after conventional loading protocol. Supportive periodontal therapy has been administered. Eleven patients (9 males and 2 females) were included. The mean age was 58.1 ± 9.9 years. A total of 17 implants were inserted and analyzed. Mean ITV was 39.3 ± 23.8 Ncm. The mean primary stability (ISQ) at T0 was 71.7 ± 10.5, whereas the mean secondary stability at T1 was 73.0 ± 7.3. The minimum follow-up was 62 months, with a maximum of 84 months (7 years) reached by four patients. Fourteen out of 15 implants were in function at a 5-year follow-up (survival rate 93.3%). Two implants showed peri-implantitis. Seventeen bone samples were collected (13 in the mandible and 4 in the maxilla). The mean percentage of marrow spaces and lamellar bone was 41.6% and 58.4%, respectively. Class 3, according to Misch classification, was found as the mean value of radiological bone density. It can be concluded that implant-supported rehabilitation in kidney-transplanted patients is possible. Adequate periodontal maintenance allows implant rehabilitation in kidney transplanted patients with long-term sufficient survival rates.

Can radiomic features extracted from intra-oral radiographs predict physiological bone remodelling around dental implants? A hypothesis-generating study.

AIM: The rate of physiological bone remodelling (PBR) occurring after implant placement has been associated with the later onset of progressive bone loss and peri-implantitis, leading to medium- and long-term implant therapy failure. It is still questionable, however, whether PBR is associated with specific bone characteristics. The aim of this study was to assess whether radiomic analysis could reveal not readily appreciable bone features useful for the prediction of PBR. MATERIALS AND METHODS: Radiomic features were extracted from the radiographs taken at implant placement (T0) using LifeX software. Because of the multi-centre design of the source study, ComBat harmonization was applied to the cohort. Different machine-learning models were trained on selected radiomic features to develop and internally validate algorithms capable of predicting high PBR. In addition, results of the algorithm were included in a multivariate analysis with other clinical variables (tissue thickness and depth of implant position) to test their independent correlation with PBR. RESULTS: Specific radiomic features extracted at T0 are associated with higher PBR around tissue-level implants after 3 months of unsubmerged healing (T1). In addition, taking advantage of machine-learning methods, a naive Bayes model was trained using radiomic features selected by fast correlation-based filter (FCBF), which showed the best performance in the prediction of PBR (AUC = 0.751, sensitivity = 66.0%, specificity = 68.4%, positive predictive value = 73.3%, negative predictive value = 60.5%). In addition, results of the whole model were included in a multivariate analysis with tissue thickness and depth of implant position, which were still found to be independently associated with PBR (p-value < .01). CONCLUSION: The combination of radiomics and machine-learning methods seems to be a promising approach for the early prediction of PBR. Such an innovative approach could be also used for the study of not readily disclosed bone characteristics, thus helping to explain not fully understood clinical phenomena. Although promising, the performance of the radiomic model should be improved in terms of specificity and sensitivity by further studies in this field.

Influence of buccal and palatal bone thickness on post-surgical marginal bone changes around implants placed in posterior maxilla: a multi-centre prospective study.

BACKGROUND: Numerous clinical variables may influence early marginal bone loss (EMBL), including surgical, prosthetic and host-related factors. Among them, bone crest width plays a crucial role: an adequate peri-implant bone envelope has a protective effect against the influence of the aforementioned factors on marginal bone stability. The aim of the present study was to investigate the influence of buccal and palatal bone thickness at the time of implant placement on EMBL during the submerged healing period. METHODS: Patients presenting a single edentulism in the upper premolar area and requiring implant-supported rehabilitation were enrolled following inclusion and exclusion criteria. Internal connection implants (Twinfit, Dentaurum, Ispringen, Germany) were inserted after piezoelectric implant site preparation. Mid-facial and mid-palatal thickness and height of the peri-implant bone were measured immediately after implant placement (T0) with a periodontal probe and recorded to the nearest 0.5 mm. After 3 months of submerged healing (T1), implants were uncovered and measurements were repeated with the same protocol. Kruskal-Wallis test for independent samples was used to compare bone changes from T0 to T1. Multivariate linear regression models were built to assess the influence of different variables on buccal and palatal EMBL. RESULTS: Ninety patients (50 females, 40 males, mean age 42.9 ± 15.1 years), treated with the insertion of 90 implants in maxillary premolar area, were included in the final analysis. Mean buccal and palatal bone thickness at T0 were 2.42 ± 0.64 mm and 1.31 ± 0.38 mm, respectively. Mean buccal and palatal bone thickness at T1 were 1.92 ± 0.71 mm and 0.87 ± 0.49 mm, respectively. Changes in both buccal and palatal thickness from T0 to T1 resulted statistically significant (p = 0.000). Changes in vertical bone levels from T0 to T1 resulted not significant both on buccal (mean vertical resorption 0.04 ± 0.14 mm; p = 0.479) and palatal side (mean vertical resorption 0.03 ± 0.11 mm; p = 0.737). Multivariate linear regression analysis showed a significant negative correlation between vertical bone resorption and bone thickness at T0 on both buccal and palatal side. CONCLUSION: The present findings suggest that a bone envelope > 2 mm on the buccal side and > 1 mm on the palatal side may effectively prevent peri-implant vertical bone resorption following surgical trauma. TRIAL REGISTRATION: The present study was retrospectively recorded in a public register of clinical trials ( www. CLINICALTRIALS: gov - NCT05632172) on 30/11/2022.

Does new bone formation vary in different sites within the same maxillary sinus after lateral augmentation? A prospective histomorphometric study.

OBJECTIVE: The aim of this study was to evaluate histomorphometric outcomes of lateral maxillary sinus augmentation in different areas of the same cavity and to correlate results to bucco-palatal sinus width (SW) and residual bone height (RBH). MATERIAL AND METHODS: Patients needing maxillary sinus floor elevation (RBH <5 mm) to insert two nonadjacent implants were treated with lateral augmentation using a composite graft. Six months later, two bone-core biopsies (mesial/distal) were retrieved in implant insertion sites. SW and RBH were measured on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were evaluated by multivariate linear regression analysis. RESULTS: Twenty patients underwent sinus augmentation, and eighteen were included in the final analysis (two dropouts for membrane perforation). Mean newly formed mineralized tissue percentage (%NFMT) after 6 months in mesial and distal sites was 17.5 ± 4.7 and 11.6 ± 4.7, respectively (p = .0004). Multivariate linear regression showed a strong negative correlation between SW and %NFMT (ß coefficient=-.774, p < .0001) and no correlation between RBH and %NFMT (ß coefficient =-.038, p = .825). CONCLUSIONS: The present study confirms that %NFMT after lateral sinus augmentation occurs at different rates in different anatomical areas of the same maxillary sinus, showing a strong negative correlation with SW, whereas no influence of RBH was observed. Clinicians should regard SW as a guide for graft selection and to decide duration of the healing period. Researchers should consider SW as a predictor variable, when comparing regenerative outcomes of different biomaterials by using maxillary sinus as an experimental model.

Implant Survival in Renal-Transplanted Patients: A Prospective Long-Term Study.

The present study aims to assess the feasibility of implant rehabilitation in kidney-transplanted patients. Patients with kidney transplantation included in periodontal supportive care and at least one year of dialysis with mono- or partial edentulism were eligible for this study. Histomorphometric evaluation of the harvested bone was matched with radiological bone assessment. Implant stability was also monitored with resonance frequency analysis and insertion torque value. Fixed cemented prostheses have been delivered after conventional loading protocol. Supportive periodontal therapy has been administered. Eleven patients (9 males and 2 females) were included. The mean age was 58.1 ± 9.9 years. A total of 17 implants were inserted and analyzed. Mean ITV was 39.3 ± 23.8 Ncm. The mean primary stability (implant stability quotient) at T0 was 71.7 ± 10.5, whereas the mean secondary stability at T1 was 73.0 ± 7.3. The minimum follow-up was 62 months, with a maximum of 84 months (7 years) reached by 4 patients. Fourteen out of 15 implants were in function at a 5-year follow-up (survival rate: 93.3%). Two implants showed peri-implantitis. Seventeen bone samples were collected (13 in the mandible and 4 in the maxilla). The mean percentage of marrow spaces and lamellar bone was 41.6% and 58.4%, respectively. Class 3, according to Misch classification, was found as the mean value of radiological bone density. It can be concluded that implant-supported rehabilitation in kidney-transplanted patients is possible. Adequate periodontal maintenance allows implant rehabilitation in kidney-transplanted patients with long-term sufficient survival rates.

Indications for implant-supported rehabilitation of the posterior atrophic maxilla: A multidisciplinary consensus among experts in the field utilising the modified Delphi method.

PURPOSE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction. MATERIALS AND METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned. RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement. CONCLUSION: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

Marginal bone changes around platform-switched conical connection implants placed 1 or 2 mm subcrestally: A multicenter crossover randomized controlled trial.

INTRODUCTION: This study analyzes early marginal bone modifications occurring around platform-switched implants with conical connection placed 1 or 2 mm subcrestally. METHODS: This crossover randomized controlled trial enrolled partially edentulous patients needing two implants in either the posterior maxilla or mandible. Each patient received two platform-switched implants with conical connection inserted 2 mm (Test) and 1 mm (Control) subcrestally. Definitive abutments were immediately connected and, after 4 months of unsubmerged healing, screwed metal-ceramic crowns were delivered. Radiographs were taken at implant placement (T0), prosthesis delivery (T1), and after 1 year of prosthetic loading (T2). RESULTS: Fifty-one patients (25 males and 26 females; mean age 61.2 ± 12.1 years) totaling 102 implants were included in the final analysis. Mean peri-implant bone level (PBL) reduction from T0 to T2 was not significantly different around Test (0.49 ± 0.32 mm) and Control implants (0.46 ± 0.35 mm; p = 0.66). Multivariate linear regression models highlighted a significant positive correlation between history of periodontitis and PBL reduction. At T2, no Test group implant and 6 Control group implants exhibited PBL below the implant platform (11.8% of Control group implants). CONCLUSION: No significant differences in peri-implant marginal bone changes were demonstrated after 1 year of prosthetic loading between platform-switched implants with conical connection inserted either 1 or 2 mm subcrestally. However, 2 mm subcrestal placement resulted in deeper implant positioning at T2, with no exposure of treated implant surface and potential preventive effect against subsequent peri-implant pathology.

Presence of microbrush remnants on the adhesion surface: A microscopical analysis.

OBJECTIVES: the aim of this ex vivo report was to evaluate, on a microscopical analysis, the presence of microbrush remnants on in the adhesive surface in extracted teeth. METHODS: Twenty extracted teeth were divided into four groups. Half of the teeth were prepared as Class I cavities, whereas the other half as Class II cavities, according to Black classification. The teeth were conditioned with primer and bonding, both applied with microbrushes. Each of these groups was divided into halves, and the two sub-groups received a polymerization process or not, respectively. The teeth were then analyzed by scanning electron microscopy working in environmental mode. RESULTS: All of the analyzed surfaces (100%) showed the presence of residual bristles on the adhesion surface. CONCLUSIONS: Microscopical analysis showed the presence of residual bristles in the 100% of the surfaces treated with Black Classes I and II cavities. Further studies are necessary to evaluate the influence of this factor on the adhesion strength and capacity. CLINICAL SIGNIFICANCE: Clinician should be aware of the realistic possibility of the presence of bristles belonging to disposable applicators in the adhesive interface of Black's class I and II cavities. The impact of these remnants has still to be ascertained.

In Vitro Qualitative Evaluation of Root-End Preparation Performed by Piezoelectric Instruments.

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.

Guided Bone Regeneration with Concentrated Growth Factor Enriched Bone Graft Matrix (Sticky Bone) vs. Bone-Shell Technique in Horizontal Ridge Augmentation: A Retrospective Study.

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.

Factors influencing the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses: A multicenter cross-sectional study.

BACKGROUND: Peri-implantitis is widely recognized as a major cause of late implant failure, both in pristine and regenerated bone. The present study aims to evaluate the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses and to analyze possible risk factors. METHODS: A cross-sectional study was conducted in four centers including patients who underwent lateral or transcrestal sinus augmentation and received dental implants. Clinical and anamnestic data were collected using a standardized form. Univariate and multivariate logistic regression analyses have been performed for both implant-level and patient-level variables. Subsequently, a multilevel logistic mixed-effect model was built to analyze variables correlated with the occurrence of peri-implantitis. RESULTS: A total of 156 patients (61 males and 95 females; mean age: 60.9 ± 11.6 years) with 315 implants inserted into augmented maxillary sinuses with a follow-up ranging from 1 to 18 years were evaluated. Seven implants in seven patients were previously lost for peri-implantitis (2.2% and 4.5% at implant- and patient-level, respectively); 250 implants showed no signs of peri-implant diseases (79.4%), 34 implants presented mucositis (10.8%), and 24 implants exhibited peri-implantitis (7.6%). Corresponding data evaluated at patient-level were 125 (80.1%), 17 (10.9%), and 14 (9.0%), respectively. At the multilevel analysis, history of periodontitis, sinus elevation with lateral approach, and one-stage sinus floor elevation significantly correlated with the occurrence of peri-implantitis (P <0.001). CONCLUSIONS: History of periodontitis confirmed its well-known role as a risk factor for peri-implant pathologies. In addition, both lateral window technique and one-stage sinus floor elevation seemed to represent significant risk factors for peri-implantitis.

Retracted publications and their citation in dental literature: A systematic review.

OBJECTIVES: The present systematic review aimed to perform an in-depth analysis of the different features of retracted publications in the dental field. MATERIAL AND METHODS: This review has been recorded in the PROSPERO database (CRD42017075634). Two independent reviewers performed an electronic search (Pubmed, Retraction Watch) for retracted articles in dental literature up to December 31, 2018. RESULTS: 180 retracted papers were identified, the first published in 2001. Retractions increased by 47% in the last four-year period (2014-2018), when compared with 2009-2013 (94 and 64 retracted publications, respectively). Author misconduct was the most common reason for retraction (65.0%), followed by honest scientific errors (12.2%) and publisher-related issues (10.6%). The majority of retracted research was conducted in Asia (55.6%), with 49 papers written in India (27.2%). 552 researchers (89%) are listed as authors in only one retracted article, while 10 researchers (1.6%) are present in five or more retracted publications. Retracted articles were cited 530 times after retraction: the great majority of these citations (89.6%) did not consider the existence of the retraction notice and treated data from retracted articles as reliable. CONCLUSIONS: Retractions in dental literature have constantly increased in recent years, with the majority of them due to misconduct and fraud. The publication of unreliable research has many negative consequences. Studies derived from such material are designed on potentially incorrect bases, waste funds and resources, and most importantly, increase risk of incorrect treatment for patients. Citation of retracted papers represents a major issue for the scientific community.

Wedge-Shaped Implants for Minimally Invasive Treatment of Narrow Ridges: A Multicenter Prospective Cohort Study.

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.

Piezoelectric bone surgery for lateral sinus floor elevation compared with conventional rotary instruments: A systematic review, meta-analysis and trial sequential analysis.

AIMS: To evaluate whether piezoelectric bone surgery (PBS) for lateral maxillary sinus floor elevation reduces risk of intraoperative complications, requires prolonged surgical time and improves the survival rate of dental implants in comparison with conventional rotary instruments. MATERIALS AND METHODS: This meta-analysis followed PRISMA guidelines and was registered in the PROSPERO database (CRD42019122972). The PubMed, Embase, Scopus and Open Grey databases were screened for articles published from 1 January 1990 to 31 December 2018. The selection criteria included randomised controlled trials (RCTs) and case-control studies (CCTs) comparing PBS with rotary instruments in lateral sinus augmentation and reporting intraoperative and postoperative outcomes (e.g. sinus membrane perforations, surgical time and implant failure rate). The risk of bias assessment was performed using the Cochrane Collaboration's tool for RCTs. A meta-analysis was performed, and the power of the meta-analytic findings was assessed via trial sequential analysis (TSA). RESULTS: Four RCTs met the inclusion criteria and were included in the review. The meta-analysis showed that, although a lower incidence of membrane tearing occurred when using PBS, the difference between the two groups was not significant. However, the power of evidence for this outcome, as determined by the TSA, was weak. Moreover, there was moderate evidence suggesting that PBS prolongs the surgery duration (mean difference of 3.43 minutes), whilst insufficient data was present to assess if PBS improves the survival rate of implants inserted in augmented sinuses. CONCLUSIONS: The power of the evidence was too weak to confirm the above-mentioned findings and further well-designed randomised clinical trials are needed to draw definitive conclusions.

Piezoelectric bone surgery for implant site preparation compared with conventional drilling techniques: A systematic review, meta-analysis and trial sequential analysis.

PURPOSE: To evaluate whether the use of piezoelectric bone surgery (PBS) for implant site preparation reduces surgical time, improves implant stability, preserves marginal bone level and improves the survival rate of oral implants compared with conventional drilling techniques. MATERIALS AND METHODS: This meta-analysis followed the PRISMA (preferred reporting items for systematic review and meta-analysis) guidelines and was registered in the PROSPERO (international prospective register of systematic reviews) database (CRD42019142749). The PubMed, Embase, Scopus and Open Grey databases were screened for articles published from 1 January 1990 to 31 December 2018. The selection criteria included randomised controlled trials (RCTs) and case-control studies (CCTs) comparing the PBS with conventional rotary instruments for implant site preparation, and reporting any of the selected clinical outcomes (surgical time, implant stability, marginal bone variations and implant failure rate) for both groups. The risk of bias assessment was performed using the Cochrane Collaboration tool for RCTs and the Newcastle-Ottawa scale (NOS) for CCTs. A meta-analysis was performed, and the power of the meta-analytic findings was assessed by trial sequential analysis (TSA). RESULTS: Eight RCTs and one CCT met the inclusion criteria and were included in the review. The meta-analysis and the TSA showed moderate evidence suggesting that the PBS prolongs surgery duration and improves secondary stability 12 weeks after implant placement compared with conventional drilling techniques. Insufficient data are available in literature to assess if the PBS reduces marginal bone loss and/or improves the implant survival rate compared with conventional drilling techniques. CONCLUSIONS: Adequately powered randomised clinical trials are needed to confirm the PBS positive effect on the secondary stability and to draw conclusions about the influence of PBS on marginal bone stability and implant survival.

Factors Influencing Early Marginal Bone Loss around Dental Implants Positioned Subcrestally: A Multicenter Prospective Clinical Study.

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.

Efficacy of Alveolar Ridge Preservation after Maxillary Molar Extraction in Reducing Crestal Bone Resorption and Sinus Pneumatization: A Multicenter Prospective Case-Control Study.

AIM: To evaluate, with three-dimensional analysis, the effectiveness of alveolar ridge preservation (ARP) after maxillary molar extraction in reducing alveolar bone resorption and maxillary sinus pneumatization when compared to unassisted socket healing. METHODS: Patients were included in the study following inclusion criteria and underwent minimally traumatic maxillary molar extraction followed by ARP using synthetic nanohydroxyapatite (Fisiograft Bone, Ghimas, Italy) (test group) or unassisted socket healing (control group). Cone-beam computerized tomographies (CBCT) were performed immediately after tooth extraction (T0) and 6 months postoperatively (T1). CBCTs were superimposed by using a specific software (Amira, Thermo Fisher Scientific, USA) and the following items were analyzed in both groups: (i) postextractive maxillary sinus floor expansion in coronal direction and (ii) postextractive alveolar bone dimensional changes (both vertical and horizontal). All data were tested for normality and equality of variance and subsequently analyzed by independent samples T-test and Mann-Whitney test. RESULTS: Thirty patients were treated by three centers and twenty-six (test n=13; control n=13) were included in the final analysis. Mean sinus pneumatization at T1 was 0.69±0.48 mm in the test group and 1.04±0.67 mm in the control group (p=0.15). Mean vertical reduction of the alveolar bone at T1 was 1.62±0.49 mm in the test group and 2.01±0.84 mm in the control group (p=0.08). Mean horizontal resorption of crestal bone at T1 was 2.73±1.68 mm in test group and 3.63±2.24 mm in control group (p=0.24). CONCLUSIONS: It could be suggested that ARP performed after maxillary molar extraction may reduce the entity of sinus pneumatization and alveolar bone resorption, compared to unassisted socket healing. This technique could decrease the necessity of advanced regenerative procedures prior to dental implant placement in posterior maxilla.

Immediate Loading of Implant-Supported Single Crowns after Conventional and Ultrasonic Implant Site Preparation: A Multicenter Randomized Controlled Clinical Trial.

AIM: To compare implant survival rate and marginal bone loss (MBL) of immediately loaded single implants inserted by using ultrasonic implant site preparation (UISP) (test) and conventional rotary instrumentation (control). METHODS: Two single implants were inserted for each patient: after randomization, test site was prepared by using an ultrasonic device (Piezosurgery Touch, Mectron, Italy) and control site was prepared by using the drills of the selected implant system (Premium AZT, Sweden & Martina, Italy), until reaching a final diameter of 3 mm in both groups. Identical implants (3.8x11.5 mm) were inserted in all sites at crestal level. Impressions were taken and screwed resin single crowns with platform-switched provisional abutments were delivered with 48 hours. Periapical radiographs were taken at provisional crown insertion (T0), 6 months (T1) and one year (T2) after prosthetic loading to measure MBL. All data were tested for normality and subsequently analyzed by paired samples t-test and forward multiple linear regression. RESULTS: Forty-eight patients were treated in six centers with the insertion of ninety-six implants (48 test; 48 control). Four implants in four patients failed within the first six months of healing (two in test group; two in control group; no difference between groups). Forty patients (age 60.1±10.7 years; 22 female, 18 male) were included in the final analysis. Mean MBL after six months of loading was 1.39±1.03 mm in the test group and 1.42±1.16 mm in the control group (p>0.05) and after one year was 1.92±1.14 mm and 2.14±1.55 mm in test and control, respectively (p>0.05). CONCLUSIONS: No differences in survival rate and MBL were demonstrated between UISP and conventional site preparation with rotary instruments in immediately loaded dental implants: UISP, with its characteristics of enhanced surgical control and safety in proximity of delicate structures, may be used as a reliable alternative to the traditional drilling systems.