Coronectomy of impacted mandibular third molars: a clinical and radiological retrospective case series study with 2-9 years of follow-up / Coronectomía de terceros molares mandibulares impactados: un estudio de serie de casos retrospectivo clínico y radiológico con 2-9 años de seguimiento

Background: Impacted mandibular third molars occasionally are in intimate relation to the inferior alveolar nerve (IAN). Coronectomy has been proposed as a good alternative to prevent injury of the IAN. The present study evaluates the clinical and radiological outcomes of impacted mandibular third molars presenting radiographic signs associated with a high risk of IAN injury, and which were treated with the coronectomy technique. Material and Methods: A retrospective case series evaluated the outcomes of coronectomies of impacted mandibular third molars. The inclusion criteria were: available preoperative, immediate postoperative and two-year panoramic radiographs, preoperative cone-beam computed tomography (CBCT), and a complete case history. The clinical evaluation comprised intraoperative complications (mobilized fragments of root and damage to adjacent structures), short-term complications (sensory alterations and postoperative infection), and long-term complications (infection or oral exposure). The IAN position with respect to the roots, root shape, eruption status, third molar position, radicular-complex migration and bone above roots were radiographically evaluated as well. Results: Approximately a total of 2000 mandibular third molars were removed from 2011 to 2022. Of these, 39 molars in 34 patients were partially extracted using the coronectomy technique. The mean age was 36 years (range 22-77), and the mean follow-up was 28 months (range 24-84). There were two short-term postoperative infections. One of them was resolved through reintervention to remove the roots after antibiotic treatment, while the other required hospital admission and removal of the roots. One case of short-term transient lingual paresthesia was also recorded. Two long-term oral exposures were detected, and the root fragments had to be extracted. There were no permanent sensory alterations...(AU)

Comparison of patient-centered outcomes measures between low-speed drilling without irrigation and high-speed drilling with irrigation: A randomized clinical trial.

OBJECTIVE: To compare patient satisfaction during surgery, postoperative pain and inflammation and quality of life between high-speed drilling with irrigation and low-speed drilling without irrigation for implant bed preparation. MATERIALS AND METHODS: Sixty-six posterior single edentulous patients were included in a randomized controlled clinical trial. Implant beds were created using high-speed drilling with irrigation (control group) or low-speed drilling without irrigation (test group). Patient satisfaction during surgery (in relation to drilling-time perception, vibration, pressure, noise, comfort, and drowning sensation) and postoperative pain and inflammation were evaluated using a 100-mm visual analogue scale (VAS)-based questionnaire. Quality of life was analyzed with a Likert scale (in relation to mouth opening, chewing, speaking, sleeping, daily routine, and job). The follow-up period was 7 days. RESULTS: Patient satisfaction in relation to drilling-time perception, vibration, pressure, and noise did not show statistically significant differences (p > .05). The highest scores of drowning sensation (p < .05) were correlated (moderate correlation (r = .57)) with lowest scores of comfort (p < .005). Both postoperative pain and inflammation means were significantly higher in the control group than in the test group. No significant differences in quality of life were observed during the postoperative period (p > .05). CONCLUSION: Low-speed drilling without irrigation for single implant site preparation was more comfortable for patients than high-speed drilling with irrigation, due to the correlation between important drowning sensation and low perceived comfort. Postoperative pain and inflammation were lower for low-speed drilling without irrigation. Further studies are needed to validate or refute these results.

Ultrasonic osteotomy and regeneration with A-PRF+ for periapical surgery of a mandibular molar with root cyst perforating the lingual osseous cortex: A case report.

Background: Periapical surgery is a complex dental procedure that remains a considerable challenge in clinical practice. The use of APRF+ membranes and piezoelectric osteotomy help to improve outcomes and increase the efficiency and speed of recovery. Material and Methods: This case report describes a 20 years-old man with a periapical lesion which perforated the lingual cortex in a lower mandibular molar. A periapical surgery was performed with endoscope magnification and ultrasonic osteotomy. Apicectomy and retrograde cavities were performed using a piezoelectric scalpel and sealed using a bioceramic sealer. The osteolytic defect was filled with A-PRF+ membranes and the bone cortex was repositioned trough a micro-screw. Results: The histological analysis concluded an inflammatory odontogenic cyst. The postoperative period was uneventful with pain and mild oedema until the fourth day. Short-term follow-up showed the beginnings of bone regeneration and correct healing of the surgery without periodontal defects. Two-year follow-up showed favorable results and regeneration of the bone defect. Conclusions: Periapical surgery with magnification, ultrasonic osteotomy repositioning and application of A-PRF+ membranes as an adjuvant proved to be an effective approach for the regeneration of the osteolytic process, allowing the preservation of the tooth. Promising short and long-term results were shown for this case report. Key words:Periapical surgery, osteotomy, ultrasound, A-PRF+.

Influence of abutment shape on peri-implant tissue conditions: A randomized clinical trial.

OBJECTIVE: To analyze the influence of 3-mm high abutments with different shapes (cylindrical abutment vs. wide abutment) on marginal bone-level changes (bone loss and bone remodeling). The influence of abutment shape on implant success, probing pocket depth (PPD), and bleeding on probing (BoP) was studied as secondary objectives. MATERIALS AND METHODS: Patients with a partially edentulous area requiring fixed dental prostheses by two implants in the posterior mandible or maxilla were included. The implants were 1 mm subcrestally placed, and osseointegration healing was submerged. Three-mm high abutments with two different shapes were randomly placed in second-stage surgery: cylindrical abutments (cylindrical group) and wide abutments (wide group). Marginal bone-level changes were measured using parallelized periapical radiographs at abutment placement, at definitive prosthesis placement, and at 1, 3, 6, and 12 months after loading. PPD and BoP were likewise measured at the control visits. RESULTS: Sixty-four dental implants in 25 patients were included. Statistically significant differences were found in bone-level changes. The cylindrical group exhibited less mean marginal bone remodeling (MBR) and marginal bone loss (MBL) than the wide group (p < .05). Moreover, the cylindrical group showed significantly less BoP (p < .05). CONCLUSION: Abutment shape had a significant influence upon marginal bone-level changes during the first 12 months. Cylindrical abutments caused less MBR and MBL than wide abutments. More clinical studies involving longer follow-ups and analyzing other abutment modifications are needed to improve our understanding of how abutments can affect peri-implant tissue stability.

Evaluation of Change in Radiographic Fractal Dimension around Dental Implants Placed with Low-Speed Drilling and Standard Drilling Protocols.

Osseointegration is a process that depends on a multitude of factors, including the type of drilling, whether biological or conventional. OBJECTIVE: Establish box-counting dimension values for radiological images in patients with implants placed with both drilling methods. MATERIAL AND METHOD: The sample included 129 implants corresponding to 50 patients. A double-blind study of data collection was carried out with the subsequent analysis of the fractal dimension as a comparative value of the state of the trabecular architecture. RESULTS: We found no significant differences (p ≥ 0.05) between the two study groups comparing both drilling techniques. The values for the conventional drilling technique are 0.24 ± 0.07 and for biological drilling: 0.19 ± 0.11 with a p-value of 0.767. CONCLUSIONS: The drilling technique does not influence the success of the procedure and the osseointegration process.

The study of bone healing after endodontic microsurgery using cone beam computed tomography: A retrospective cohort study.

Background: The main aims of this study were to evaluate mean volume reduction, radiographic healing rate and healing outcome two years after endodontic microsurgery. The effects of certain preoperative clinical factors upon preoperative volume, volumetric changes and healing outcome were also studied. Material and Methods: A clinical database was searched for patients who had undergone endodontic microsurgery and with the availability of a cone beam computed tomography (CBCT) scan preoperatively and after a control period. Volumetric analysis of the periapical area was made to assess volumetric reduction. The modified Penn 3D criteria were applied. The relationship between preoperative volume, volumetric reduction and healing outcome and certain preoperative factors was also studied. Results: Fifty-seven cases were evaluated. Initially, the bone cavities had a median volume of 163.2 mm3, and this volume decreased by 147.7 mm3 after treatment, with a radiographic healing rate of 6.2 mm3 per month. After applying the modified Penn 3D Criteria, 53 cases were classified as successful healing (93%). Regarding the influence of the different preoperative factors, patient age and sex, dental arch and cortical bone significantly influenced preoperative volume, while only the dental arch exerted a significant influence upon volumetric changes and preoperative symptoms on healing outcome. Conclusions: The CBCT data evidenced a significant volume reduction of 79.1%, with a monthly volume reduction rate of 6.2 mm3. The success rate obtained was 93%. Patient age and sex, dental arch and cortical bone influenced preoperative volume, tooth type had an impact upon the volumetric changes, and the preoperative symptoms influenced healing outcome. Key words:Cone beam computed tomography, endodontic microsurgery, healing, lesion volume, prognostic factors.

Impact of abutment geometry on early implant marginal bone loss. A double-blind, randomized, 6-month clinical trial.

OBJECTIVES: The objective of this study was to analyze the impact of the abutment width on early marginal bone loss (MBL). MATERIAL AND METHODS: A balanced, randomized, double-blind clinical trial with two parallel experimental arms was conducted without a control group. The arms were "cylindrical" abutment and "concave" abutment. Eighty hexagonal internal connection implants, each with a diameter of 4 × 10 mm, were placed in healed mature bone. The main variable was the peri-implant tissue stability, which was measured as MBL at 8 weeks and 6 months. RESULTS: The final sample consisted of 77 implants that were placed in 25 patients. 38 (49.4%) were placed using the cylindrical abutment, and the other 39 (50.6%) were placed using the concave abutment. The early global MBL of -0.6 ± 0.7 mm in the cylindrical abutment group was significantly higher than it was in the concave abutment group, in which the early global MBL was -0.4 ± 0.6 mm (p = .030). The estimated effect size (ES) was negative for the cylindrical abutment (ES = -1.3730, CI -2.5919 to -0.1327; t-value = -2.4893; p = .0139), therefore implying a loss of mean bone level, and it was positive for the concave abutment (ES = 2.8231; CI: 1.4379 to 4.2083; t-value = 4.0957; p = .0002), therefore implying an increase in the average bone level. CONCLUSIONS: The concave abutments presented significantly less early MBL at 6 months post-loading than classical cylindrical abutments did.

Endoscopic findings in periapical surgery. A cross-sectional study of 206 roots

Background: A study is made of the findings of high-magnification rigid endoscopy at the root end surface following apicoectomy of teeth subjected to periapical surgery.Material and Methods: A cross-sectional study was made of patients subjected to periapical surgery at the Unitof Oral Surgery and Implantology (University of Valencia, Valencia, Spain) between 2011 and 2019. Followingapicoectomy, the root end surfaces were inspected, with the evaluation of untreated canals, isthmuses, craze lines,crack lines, opaque dentin and gaps. Likewise, an analysis was made of the association between patient age andthe tooth type and restoration and the presence of craze lines, cracks, opaque dentin and gaps.Results: The final sample consisted of 168 patients subjected to periapical surgery, with 177 operated teeth and206 roots. Untreated canals were observed in 14 roots (6.8%). Isthmuses were identified in 74 roots (35.9%),particularly in the mesial root of the lower first molar (94.1%). In turn, craze lines were identified in 8.3% of theroots, cracks in 3.9%, and gaps in 53.4%. The prevalence of opaque dentin was 78.3%, with a greater presence inposterior teeth (90.3% in premolars and 86.2% in molars) than in anterior teeth (50.6%) (p<0.001). Patient age andtooth restoration showed no correlation to the studied parameters.Conclusions: Craze lines and crack lines were observed in less than 10% of the roots, though opaque dentin wasidentified in 73% of the roots, particularly in posterior teeth, and gaps were found in over half of the canals. (AU)

Influence of root width and dentin wall thickness evaluatedby endoscopy upon the outcome of periapical surgery. A cohort study

Background: An analysis was made of the correlation between root width, the thickness of the remaining dentinalwall as determined by endoscopy, and the outcome of periapical surgery.Material and Methods: A retrospective cohort study was carried out involving patients subjected to periapicalsurgery between 2017 and 2019 at the University of Valencia (Valencia, Spain).One year after surgery, cone-beam computed tomography (CBCT) was used to evaluate healing against the preoperative volumes. The maximum root width was measured on the postoperative CBCT scan at the apical section ofthe treated root. This measurement was transferred to the intraoperative endoscopic image, where the minimumroot width, peripheral dentin thickness, and minimum dentin thickness were recorded. Root measurements, andthe position (maxillary or mandibular) and type of tooth (roots of incisors, canines, premolars or molars) werefurther correlated to periapical surgery outcome.Results: A total of 51 patients, comprising 52 teeth and 62 roots, were included in the study. The mean measurements were: maximum root width (4.13±0.84 mm), minimum root width (2.46±0.72 mm), peripheral dentin thickness (0.77±0.2 mm) and minimum dentin thickness (0.4±0.2 mm). The success rate was 82.2%. Premolar roots showed a greater minimum dentin thickness (0.58±0.25 mm) (p<0.003) than incisor roots. No significant association was found between the different measurements and the healing rate at one year, though the roots that failed to heal showed smaller minimum dentin thickness values than the roots that healed correctly. The position and type oftooth did not influence healing outcome.Conclusions: The root width and thickness of the remaining dentin wall did not significantly influence healing.However, the roots that failed to heal showed smaller minimum dentin thickness values than the roots that healed correctly. (AU)

Maxillary Sinus Floor Augmentation with Two Different Inorganic Bovine Bone Grafts: an Experimental Study in Rabbits.

OBJECTIVE: To compare the sequential healing of maxillary sinuses grafted with two different xenogeneic bone substitutes processed at either a low (300°C) or high (1200°C) temperature. METHODS: A sinus augmentation procedure was performed bilaterally in 20 rabbits and two different xenogeneic bone grafts were randomly used to fill the elevated spaces. Healing was studied after 2 and 10 weeks, in 10 rabbits during each period. RESULTS: After 2 weeks of healing, very small amounts of new bone were observed in both groups, and were mainly confined to close to the sinus bone walls and osteotomy edges. After 10 weeks of healing, new bone was found in all regions, with higher percentages in those close to the bone walls and to the osteotomy. In this period of healing, the proportion of new bone in the 300°C group was 20.0% ± 4.3%, and in the 1200°C group it was 17.2% ± 4.3% (P = 0.162). In the 1200°C group, translucent, dark fog-like shadows in regions of the grafts were hiding portions of new bone (interpenetrating bone network). CONCLUSION: Both biomaterials provided conditions that allowed bone growth within the elevated space, confirming that both biomaterials are suitable to be used as a graft for sinus floor augmentation.

Healing of 295 Endodontic Microsurgery Cases After Long-Term (5-9 Years) Versus Middle-Term (1-4 Years) Follow-up.

INTRODUCTION: Some evidence suggests that teeth treated with endodontic surgery and considered to have healed over the short term are seen to relapse when evaluated again after 3 or more years. However, long-term evidence is limited. This study compares healing after endodontic microsurgery over long-term (5-9 years) vs middle-term (1-4 years) follow-up and assesses the influence of different healing predictors over time. METHODS: A retrospective study was made, comparing the endodontic microsurgery healing rates after 1-4 vs 5-9 years of follow-up. Healing was assessed based on clinical and radiographic parameters. Simple binary logistic regression models were used to analyze the influence of patient age and gender, the type of tooth, previous radiographic lesion size, apical extent of previous root canal filling, the presence of a post, type of restoration, and interproximal bone level upon the endodontic microsurgery healing rate. A sensitivity analysis was used excluding cases of vertical root fracture. Two calibrated observers independently evaluated the periapical radiographs. RESULTS: A total of 332 patients (60% women and 40% men) were included in the study. Of the 332 analyzed teeth, 198 were subjected to middle-term follow-up (1-4 years), with a healing rate of 86.9%, while 134 were subjected to long-term follow-up (5-9 years), with a healing rate of 67.2%. There were no statistically significant differences in terms of gender, age, type of tooth, size of the lesion, apical extent of previous root canal filling, presence of a post, or type of restoration. The regression models identified 2 statistically significant associations: cohort and interproximal bone level (P < .05). CONCLUSIONS: A success rate of 86.9% was recorded after 1-4 years of follow-up, vs 67.2% after 5-9 years. Excluding cases of vertical root fractures, in the shortest follow-up cohort (1-4 years), the healing rate was 92.5%, vs 82.6% in the cohort with longer follow-up (5-9 years). The prognosis was influenced by the crestal bone level in relation to the cementoenamel junction of the tooth, being significantly poorer when probing depth was >3 mm mesial or distal to the treated tooth.

Intraoral onlay block bone grafts versus cortical tenting technique on alveolar ridge augmentations: a systematic review

Background : To review systematically the bone gain and superficial resorption rate of the onlay block bone grafts versus the cortical tenting technique, as well as secondarily study the postoperative complications, implant survival and success rates, and peri-implant marginal bone loss. Material and Methods: Following the recommended methods for systematic reviews and meta-analyses (PRISMA), an electronic search was performed in the PubMed (MEDLINE), EMBASE and the Cochrane Library of the Cochrane Collaboration (CENTRAL) databases to identify all relevant articles published up to March 2021 on onlay block bone grafts and cortical tenting technique. Results: Eighteen papers complied with the inclusion criteria. In onlay grafts, the vertical bone gain mean was 4.24 mm, and resorption 20.91%; and 4.29 mm in the horizontal augmentation with a resorption of 10.28%. The complication rate was 14.8%. The implant survival and success rates were 100% and 92%; and the mean peri-implant bone loss ranged from 0.6 to 1.26 mm. In cortical tenting technique, the vertical bone gain mean was 6.17 mm and the resorption of 9.99%; and 5.55 mm in the horizontal augmentation with a 6.12% of resorption. The complication rate was 24.6%. The implant survival and success rates were 96.63% and 100%; and the mean peri-implant bone loss ranged from 0.27 to 0.77mm. Conclusions: Despite the limitations, both techniques offer a predicTable way to reconstruct atrophic alveolar ridges, though the cortical tenting technique seems to achieve a greater bone gain and a lower surface resorption. Current evidence is still limited due to the inadequate follow-up, lack of information referred to methodological quality and sample attrition.(AU)

Is Healing of Periapical Surgery Influenced by Endoscopic Findings Detected on the Cut Root Surface?

PURPOSE: An analysis was made of the association between the endoscopic findings of the sectioned root end surface and healing of the lesion 1 year after periapical surgery, although no studies appear to have analyzed them in relation to healing after periapical surgery. METHODS: A retrospective cohort study was made of patients subjected to periapical surgery between 2011 and 2019. After apicoectomy, the root end surface was examined, evaluating the number of canals, isthmuses, dentin cracks and craze lines, opaque dentin, and gaps between the filling material and the root canal wall. An analysis (using Generalized Estimating Equation models) was made of the association between the endoscopic findings and healing evaluated by von Arx and Kurt criteria and the modified PENN 3D criteria. The possible influence of patient age and gender and the type of tooth involved on healing was evaluated. RESULTS: A total of 108 patients (114 teeth and 128 roots) were subjected to periapical surgery. Two or more canals were detected in 27.3% of the roots (8.6% not subjected to orthograde filing), and isthmuses were identified in 18%, craze lines in 7%, cracks in 3.1%, opaque dentin in 69.5%, and gaps in 53.1% of the roots. The healing rate at 1 year according to the criteria of von Arx and Kurt was 95.4% versus 82.2% according to the modified PENN 3D criteria. Failure was more common in roots with cracks, although statistical significance was not reached (odds ratio [95% confidence interval]: 0.20 [0.01 to 4.04]; P = .200). The rest of the endoscopic findings as well as patient age and gender and the type of tooth did not influence healing (P > .05). CONCLUSIONS: In the present sample, no statistically significant associations were observed between the endoscopic and healing at 1 year after periapical surgery. Failure was more common in roots with cracks, however.

Is periapical surgery follow-up with only two-dimensional radiographs reliable? A retrospective cohort type sensitivity study / ¿El seguimiento de la cirugía periapical se realiza únicamente con radiografías bidimensionales confiable? Un estudio retrospectivo de sensibilidad de tipo cohorte

Background: Two-dimensional (2D) radiographic techniques are commonly used for assessing lesion prognosisafter endodontic surgery. The present retrospective cohort study analyzes the sensitivity and ability of differentradiographic techniques in obtaining area and volume measurements of periapical lesions.Material and Methods: Preoperative and follow-up (6-48 months) periapical and panoramic radiographs (indextest) and cone-beam computed tomography (CBCT) images (reference standard) were selected from an endodonticmicrosurgery database. Sensitivity was analyzed independently by two examiners. The areas of the 2D radio-graphic images and CBCT volumes were studied using Itk-Snap software and Romexis viewer.Results: The sample comprised 105 patients and 105 teeth, with a mean follow-up of 21 months (range 6-48). Preop-eratively, CBCT detected all the periapical areas, periapical radiography detected 67, and panoramic radiographydetected 60. Postoperatively, of the 52 cases in which CBCT detected remains of the periapical area, periapical ra-diography detected 22, and panoramic radiography detected 17. The measurements of the areas obtained by the 2Dmethods, and the volumes obtained by CBCT, had to be transformed into linear measures for comparison purpos-es. The measurements were found to be significantly different in both the preoperative and the follow-up images. Conclusions: Periapical radiography showed greater sensitivity than panoramic radiography, both preoperatively andat follow-up. The lesions measured with CBCT were larger, with significant differences than as evidenced by theperiapical and panoramic radiographs.(AU)

Factors influencing the aesthetics of smile: An observational study on clinical assessment and patient's perception.

AIM: To clinically assess the aesthetics of smile and the possible influencing factors. MATERIALS AND METHODS: In this explorative study, an initial questionnaire on demographic variables and perception of own quality of smile (Visual Analogue Scale) was administered by a first examiner. A second blinded assessor examined all patients and recorded clinical data. In addition, for each patient, the Smile Aesthetic Index (SEI) was calculated. Descriptive statistics and multilevel logistic models were performed. RESULTS: One hundred consecutive subjects were enrolled. The mean SEI was 8.4 ± 1.2, while the mean patient's perception of smile was 7.1 ± 2.0. However, they did not correlate (r = 0.16 from -0.04 to 0.34; p = .12). Gingival recessions were perceived by 21.9% of subjects, tooth alignment by 38.6%, tooth dyschromia by 34.3%, and missing papilla/diastema by 26.7%. In particular, gingival recessions were perceived when they were deeper (p = .0342), located in the upper jaw (p = .0223), and corresponding to incisors (p < .0001) and canines (p = .0159) with respect to molars. CONCLUSIONS: Clinical assessment and patient perception represent two important diagnostic phases. However, there is no correlation between them. Attention should be given to specific variables to provide the most comprehensive aesthetic analysis of smile.

Comparison of the diagnostic efficacy of 2D radiography and cone beam computed tomography in persistent apical periodontal disease: A PRISMA-DTA systematic review and meta-analysis.

OBJECTIVE: The objective of this study was to answer the question: Do conventional radiographs (periapical/panoramic) afford better diagnostic outcomes than cone beam computed tomography (CBCT) as a complement for clinical diagnosis of apical lesions with persistent apical periodontitis or disease after root canal treatment? STUDY DESIGN: Five electronic databases were searched and provided information to enable construction of a table to determine primary diagnostic measures and secondary parameters. The evidence was appraised with the Quality Assessment of Diagnostic Accuracy Studies tool and GRADEpro software. RESULTS: Twenty-seven articles (9903 diagnostic images) were included. The pooled sensitivity, specificity, area under the receiver operating characteristic curve (AUCROC), positive predictive value, negative predictive value, negative likelihood ratio, and accuracy were 0.58, 1, 0.77, 1, 0.68, 0.45, and 0.79, respectively. CONCLUSIONS: Moderate certainty evidence suggested that conventional radiographs showed poor sensitivity and excellent specificity but good diagnostic performance in terms of AUCROC and accuracy. Sensitivity, AUCROC, and negative likelihood ratio values could be reduced if the time elapsed to diagnosis after root canal treatment exceeded 5 years. The use of CBCT with a reduced field of view or a 2D radiographic technique should be weighed considering patient-specific and indication-oriented criteria as taking precedence over the therapeutic goal.

Survival Rate and Prosthetic and Sinus Complications of Zygomatic Dental Implants for the Rehabilitation of the Atrophic Edentulous Maxilla: A Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to analyze and compare the survival rate and prosthetic and sinus complications of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla. MATERIALS AND METHODS: We conducted a systematic literature review and meta-analysis, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, of clinical studies that evaluated the survival rate and prosthetic and sinus complications of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla. Four databases were consulted during the literature search: Pubmed-Medline, Scopus, Embase, and Web of Science. After eliminating duplicate articles and applying the inclusion criteria, 46 articles were selected for the qualitative analysis and 32 for the quantitative analysis. RESULTS: Four randomized controlled trials, 19 prospective clinical studies, 20 retrospective studies, and 3 case series were included in the meta-analysis. Conventional dental implants failure (n = 3549) were seen in 2.89% (IC-95% 1.83-3.96%), while zygomatic dental implants failure (n = 1895) were seen in 0.69% (IC-95% 0.21-1.16%). The measure of the effect size used was the Odds Ratio, which was estimated at 2.05 with a confidence interval of 95% between 1.22 and 3.44 (z test = 2.73; p-value = 0.006). The failure risk of conventional dental implants is 2.1 times higher than that of zygomatic dental implants. Slight heterogeneity was determined in the meta-analysis between 23 combined studies (Q test = 32.4; p-value = 0.070; I2 = 32.1%). Prosthetic complications were recorded in 4.9% (IC-95% 2.7-7.3%) and mild heterogeneity was observed in a meta-analysis of 28 combined studies (Q test = 88.2; p-value = 0.001; I2 = 69.4%). Sinus complications were seen in 4.7% (IC-95% 2.8-6.5%) and mild heterogeneity was observed in a meta-analysis of 32 combined studies (Q test = 75.3; p-value = 0.001; I2 = 58.8%). CONCLUSIONS: The high survival rate and low prosthetic and sinus complications related to zygomatic dental implants suggest the use of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla.

Culturomic and quantitative real-time-polymerase chain reaction analyses for early contamination of abutments with different surfaces: A randomized clinical trial.

BACKGROUND: Rough and/or plasma-activated abutments seem to be able to increase soft tissue adhesion and stability; however, limited evidence is available about bacterial contamination differences. PURPOSE: The aim was to investigate the oral microbiota on four dental abutments with different surfaces by quantitative real-time polymerase chain reaction (qRT-PCR) and culturomic approach. METHODS: Forty patients needing a single implant rehabilitation were involved in the study. Forty healing abutments, especially designed for the study, were divided into four groups according to the surface topography (1. machined [MAC], 2. machined plasma of argon treated [plasmaMAC], 3. ultrathin threaded microsurface [UTM], 4. UTM plasma of argon treated [Plasma UTM]). Random assignment was performed according to predefined randomization tables. All patients underwent surgical intervention for implant and contextual healing abutment positioning. After 2 months of healing, a sterile cotton swab was used for microbiological sampling for culturomics, while sterile paper points inserted into the sulcus were used for qRT-PCR. RESULTS: At the end of the study, 36 patients completed all procedures and a total of 36 abutments (9 per group) were analyzed. qRT-PCR retrieved data for 23 bacterial species whereas culturomics revealed the presence of 74 different bacteria, most of them not routinely included into oral cavity microbiological kits of analysis or never found before in the oral microenvironment. No statistically significant differences emerged analyzing the four different surfaces (p = 0.053). On the contrary, higher total and specific bacterial counts were detected in the plasma-treated surfaces compared to the untreated ones (p = 0.021). CONCLUSIONS: Abutments with different topographies and surface treatments resulted contaminated by similar oral bacterial flora. Abutments with moderately rough surface were not associated with a greater bacterial adhesion compared to machined ones. Conversely, more bacteria were found around plasma-treated abutments. Furthermore, data reported suggested to include new species not previously sought in the routine analyses of the oral bacterial microflora.

Soft tissue integration of different abutment surfaces: An experimental study with histological analysis.

OBJECTIVE: To evaluate whether abutment surface and surface bio-activation have an effect on soft tissue morphogenesis. MATERIALS AND METHODS: 36 patients (36 implants) were included. Abutments were randomly divided into 4 groups (n = 9): Smooth Surface-MAChined (MAC), Ultrathin Threaded Microsurface (UTM), MAC Plasma of Argon activated (Plasma-MAC), and UTM Plasma of Argon activated (Plasma-UTM). After 2 months of healing, soft tissue samples were collected and prepared for histological analysis. The margin of the peri-implant mucosa (PM), the apical extension of the barrier epithelium (aJE), and the apical location of the abutment (AM) were identified. Significances of differences among groups were tested by means of the Kruskal-Wallis test and between pairs of results by means of the Mann-Whitney test. RESULTS: The mean (SD) vertical dimension of the mucosa was 2.5mm (1.0), including a connective tissue portion (CTP) of 0.8mm (0.8) in the MAC group; 3.6mm (0.2) with a CTP of 1.6mm (0.4) in the Plasma-MAC group; 3.2mm (1.0), with a CPT of 0.5mm (0.6) in the UTM; and 3.3mm (0.8), with a CPT of 0.9mm (0.7) in the Plasma-UTM group. Statistically significant differences were observed in the aJE-AM height and PM-aJE profile among the four experimental groups (p = .042 and p = .039, respectively). The Mann-Whitney test indicated differences between the Plasma-abutments and the untreated abutments both for PM-AM (p = .025) and AjE-AM (p = .021). The differences appeared more evident when the preoperative soft tissue thickness was ≤2mm. CONCLUSIONS: Within its limits, the study demonstrated a favorable effect of the plasma treatment on the connective tissue portion tissues. Plasma-MAC group highlighted the best performance. This behavior appeared strictly correlated with the soft tissue thickness.

Low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation: a systematic review.

PURPOSE: This paper aims to review the evidence comparing low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation. MATERIALS AND METHODS: A systematic review was carried out based on the PRISMA statement. Four databases and gray literature were searched up to November 2020. In vitro, animal, and clinical studies were included. The variables were temperature change, drilling time, quantity of harvested bone, osteotomy precision, marginal bone loss, implant success rate, osseointegration, and the histomorphologic characteristics and cellularity of the osteotomy and of the harvested bone. Different tools for the assessment of bias were applied for each study design. RESULTS: A total of 626 articles were identified, of which 13 were included. Both low-speed drilling without irrigation (test group) and conventional drilling (control group) maintained temperatures below the critical temperature of 47 °C. The test group yielded a greater quantity and more beneficial cellular and histomorphologic properties of harvested bone, with a longer drilling time and greater osteotomy precision (p < 0.05). No significant results were obtained regarding drill wear, osseointegration, marginal bone loss, implant success rate, and histomorphology of the dental implant osteotomy (p > 0.05). The results, in particular on the osteotomy precision and quantity of harvested bone chips, should be interpreted with caution because outcomes are based in only one in vitro study. CONCLUSIONS: Low-speed drilling without irrigation seems to be comparable to conventional drilling in preparing dental implant osteotomies. In some situations, low-speed drilling without irrigation might offer advantages over conventional drilling. The results should be interpreted with caution due to the low percentage of clinical human studies. Accordingly, more clinical studies are needed to improve the scientific evidence on this topic. CLINICAL RELEVANCE: The low-speed drilling without irrigation is a valid technique for dental implant osteotomy preparation. Its higher quantity and quality of harvested autologous bone might be particularly beneficial in cases of dental implant placement with minor simultaneous bone regeneration.