Quantitative parameters of digital occlusal analysis in dental implant supported restorative reconstruction recent 5 years: a systematic review.

OBJECTIVE: The aims of this systematic review were to evaluate the clinical masticatory performance of implant-supported restorations, observe the occlusal force changes in the distribution of the implant restoration and reveal the positive and negative contributing factors of implant design and components based on the outcomes of digital occlusal measurement. MATERIAL AND METHODS: An extensive search was conducted through PubMed and CENTRAL to identify clinical trials on implant-retained restorations using digital occlusal analysis methods. Two researchers assessed the identified studies and data extraction independently, and the data synthesis strategies without meta-analysis that summarizes the effect estimates were adopted. RESULTS: The search screened 3821 titles and abstracts, then full-text analysis for 26 articles was performed, and 14 studies were included in the quantitative synthesis. Four of six studies for implant-retained overdenture showed statistically significant improved bite force when immediate loading (p = .00045, .00005, .00055, and .00005, respectively), and no statistically significant results in the other two studies (p = .225, .371, respectively.) However, the results of the favoured intervention were not statistically significant (p = .104, .166, respectively) in two studies of single posterior implant restorations. In all three studies, the bite force distributed on the implant prostheses of partially fixed implant-retained restoration increased statistically significantly (p = .013, .001, .05, respectively). CONCLUSIONS: The edentulous restoration supported by implants seems to significantly improves bite force and chewing efficiency compared with conventional dentures. Regular quantitative occlusal measurement is recommended to avoid the possible risk of overload. Smaller implants size and relatively small and flexible attachment designs may be more conducive to the stability and retention of the restoration of atrophy of alveolar bone.

Customized 3D printed nanohydroxyapatite bone block grafts for implant sites: A case series.

PATIENTS: A case series of 12 patients (mean age, 53.5 years) with horizontal ridge deficiencies had augmentations with customized 3D printed nanohydroxyapatite (3DHA) block grafts prior to implant placement. 3DHA graft materials were fabricated to fit the individual patient defects using DICOMs from CBCT images obtained from each patient. The CBCT images were then converted into the STL file format and 3DHA was reconstructed by 3D printing. Surgical bone augmentation consisted of 3DHA incorporating concentrated growth factors (CGFs) and platelet-rich fibrin (PRF) membrane. At 6 months, a bone biopsy and implantation were performed. The primary outcome was horizontal bone gain after 6 months. The secondary outcomes included information on the clinical outcomes, dimensions, and histomorphometric results. DISCUSSION: The 3DHA block graft was successful in 10 of 12 patients. Graft adjustment was not required. All 3DHA adapted and fit well at all defect sites. Maximum mean horizontal bone gains were 3.06 ± 1.02 and 3.56 ± 0.23 mm from the DICOMs and STL data sets, respectively. The volume gain was 229.8 ± 82.96 mm3. A low pain score after surgery was reported of 1.41 ± 0.51, while the healing index score increased with a maximum mean of 4.7 ± 0.67. Thirteen implants were placed with good primary stability (ISQ = 65 ± 4.08), without additional guided bone regeneration. Histomorphometric analysis revealed that new bone formation, bone tissue, residual grafts, and connective tissue were 28.6 ± 1.88, 30.48 ± 4.81, 19.82 ± 4.07, and 20.81 ± 4.41%, respectively. CONCLUSIONS: A customized 3DHA block graft is a viable treatment option for primary implant-site augmentation.

Polycaprolactone versus collagen membrane and 1-year clinical outcomes: A randomized controlled trial.

BACKGROUND: Polycaprolactone (PCL) is a synthetic aliphatic polyester widely used in biomedical applications with biodegradability in the body and promotes cell proliferation and differentiation. A newly developed bilayered PCL membrane was developed for possibly being used as a membrane in guided bone regeneration (GBR). PURPOSE: To compare the clinical efficacy between a newly developed bilayered PCL membrane with a Cytoplast™ RTM collagen membrane for GBR with simultaneous implant placement. MATERIALS AND METHODS: Twenty-four patients were randomized to PCL or RTM group, and a total of 24 dental implants were placed. Primary outcomes were patient mean buccal bone thickness (BBT) immediately postimplantation and at 6 months using cone-beam CT and soft tissue surface dimensional changes (STC) at crown insertion, 6 months, and 1 year after loading using intraoral scanner. Secondary outcomes included success rate, clinical parameters, healing index, implant stability, pink esthetic score, and marginal bone levels. RESULTS: The percentage of reduced BBT at 6 months was 32.38%, 25.94%, and 23.96% in the test group and 34.42%, 14.75%, and 6.34% in the control group at the corresponding levels. The mean difference of changed BBT associated with PCL membrane, when compared to collagen membrane, at 6 months was -0.02 ± 0.18 mm (95% confidence interval [CI]: -0.40 to 0.35), 0.29 ± 0.28 mm (95% CI: -0.29 to 0.87), and 0.62 ± 0.38 mm (95% CI: -0.17 to 1.42) at 0, 2, and 4 mm from implant shoulder. Minimal loss of STC was observed in both groups up to 1 year of loading. The mean difference loss of surface dimensional change associated with PCL membrane, when compared to collagen membrane, at 1 year of loading was 0.31 ± 0.19 mm (95% CI: -0.07 to 0.70), 0.22 ± 0.26 mm (95% CI: -0.33 to 0.76), and 0.17 ± 0.30 mm (95% CI: -0.45 to 0.78) at 0, 2, and 4 mm from implant shoulder. None of these differences were statistically significant (unpaired t-test, degrees of freedom [df] = 22; p > 0.05). CONCLUSION: Within the limits of this trial, both barrier membranes resulted in comparable outcomes for GBR with implant placement after 1 year in function. Further research is necessary with a larger sample size.

Oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19): A systematic review.

We reviewed the prevalence, the likely aetiopathogenesis, and the management of oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2). English language manuscripts searched using standard databases yielded 26 articles that met the inclusion criteria. In total, 169 cases (75 females; 94 males) from 15 countries with a spectrum of COVID-19 severities were reviewed. Gustatory perturbations were prevalent in over 70%. Mucocutaneous manifestations were reported predominantly on the tongue, palate, buccal mucosa, gingivae, and lips and included ulcers, blisters, erosions, papillary hyperplasia, macules, glossitis, and mucositis. Ulcerative lesions, present in over 50 percent, were the most common oral manifestation. Lesions resembling candidal infections, with burning mouth, were prevalent in 19%. Petechiae and angina bullosa were generally seen, subsequent to COVID-19 therapies, in 11%. Ulcerated, necrotic gingivae were documented in severely ill with poor oral hygiene. These manifestations, present across the COVID-19 disease spectrum, were commonly associated with the immunosuppressed state and/ or the concurrent antimicrobial/steroidal therapies. In summary, a wide variety of orofacial mucocutaneous lesions manifest in COVID-19. They are likely to be secondary to the disease-associated immune impairment and/or pharmaco-therapy rather than a direct result of SARS-CoV-2 infection per se.

A 5-year Prospective validation of the Miller-McEntire Periodontal Prognostic Index.

Background: This 5-year prospective survival analysis study aimed to examine the prognostic validity of a periodontal prognostic score specific for diseased molars: Miller-McEntire Periodontal Prognostic Index (MMPPI). Materials and Methods: One thousand and twenty-three molars were evaluated from 129 patients. The MMPPI scoring factors included age, smoking, diabetes, probing depth, mobility, molar type, and furcation involvement. MMPPI was computed as the sum of scores for all seven prognostic factors. Appropriate periodontal treatment and supportive periodontal therapy were provided. All patients were evaluated at baseline and annually posttreatment up to 5 years. Hazard risk ratios (HR) were computed for each prognostic factor, MMPPI scores assigned. The MMPPI score were then analyzed using Kaplan-Meier survival analyses. Results: A total of 31/1023 (0.3%) molars were extracted over the 5-year follow-up duration. Significant and positive hazard risk ratio (HR = 1.9) was noted for the total MMPPI score, validating its prognostic value for molar survival at 5 years prospectively. Kaplan-Meier survival analysis showed a significantly lower probability of molar survival with increasing MMPPI scores, where total score >8 showed worse survival probability over time. The hazard risk ratio was significant for individual prognostic factors: mobility (HR = 1.63), smoking (HR = 1.61), diabetes mellitus (DM) (HR = 1.4), molar type (1.97), and furcation involvement (2.22). Conclusions: The findings of the current study demonstrate significant prognostic validity of MMPPI scores for molar loss for 5 years, and a score >8 showed markedly worse molar survival probability in a well-maintained, university-based, prospective cohort. Mobility, smoking, DM, molar type, and furcation were component factors that were significant individual predictors.

Clinical evaluation of 3D printed nano-porous hydroxyapatite bone graft for alveolar ridge preservation: A randomized controlled trial.

BACKGROUND/PURPOSE: Ridge resorption after tooth extraction may result in inadequate bone volume and unfavorable ridge architecture for ideal implant placement. The use of bone substitutes has been advocated to fill extraction sites and to enhance primary implant stability. This study was made to evaluate the clinical efficacy of novel 3D printed nano-porous hydroxyapatite (3DP HA, test group) in comparison to nano-crystalline bone graft (NanoBone®, control group) in alveolar ridge preservation prior to implant placement. MATERIALS AND METHODS: Thirty patients were randomized into two groups following tooth extraction. All extracted sockets were filled with 3DP HA or NanoBone® and covered with a non-resorbable membrane. After four months, cone-beam computed tomography (CBCT) and intraoral scanner were used to measure dimensional changes of bone and soft tissue surface. Bone core specimens were harvested for histological analysis during implant osteotomy. Implant stability was assessed using a modified damping capacity analysis. RESULTS: At four months postoperatively, dimensional changes in soft tissue surface resorption were less in the test group than in the control group; however, alveolar bone resorption was the same in both groups. Histological analysis revealed new bone formation, residual graft and fibrous connective tissue in both groups. The average primary implant stability (IST) value for both groups was approximately 70. There was no statistically significant difference in all parameters between two groups (p > 0.05). CONCLUSION: 3DP HA could potentially be used as an alternative bone graft material for alveolar ridge preservation.

Biomechanical Aspects of Various Attachments for Implant Overdentures: A Review.

There have been considerable recent technological developments for implant overdenture attachments. This study presents an overview of the biomechanical and biomolecular aspects of various attachments for implant overdenture. Available articles on attachments for implant overdenture were reviewed from January 1980 to August 2021 in the ScienceDirect, MEDLINE/PubMed, and Web of Science resources, and relevant studies were included in this study. We focused on the following topics: attachment systems, retention of various attachments, stress distribution with different attachments, the design and fabrication of attachments, digital techniques in overdenture attachments, and the effects of attachments in peri-implant health. We found that plastic resin is commonly used for ball and bar attachments, whereas nylon resin is commonly used in locator attachments. The locator system offers a valuable attachment option for implant-retained overdenture. Attachment retention reduces while lateral force increases with implant inclination in overdenture. The higher the retention of an overdenture attachment, the higher the transferred stresses. Additionally, clip loading produces more stress in implants and precision elements than bar-retained dentures. As such, we conclude that the ball and locator systems the best overdenture systems due to their superior tissue response, survival rate, and patient satisfaction.

Digital occlusal analysis of pre and post single posterior implant restoration delivery: A pilot study.

OBJECTIVES: The purposes of this study were to analyze the effects of single posterior implant restorations delivery on the redistribution of bite force and to evaluate the changes in occlusal force distribution of prostheses and potential influencing factors on occlusion variation at different stages. MATERIALS AND METHODS: Thirty-two single posterior restorations in 30 participants (18 women and 12 men aged 27 to 75 years) were placed into either a unilateral single-tooth defect (n = 17) or on either side of a bilateral teeth defects (n = 15). The bite force (%) of the prostheses, teeth and segments at the maximum intercuspation position (MIP) was evaluated using a T-scan at 5 stages (pre-placement, immediately following placement, and 2 weeks, 3 months, and 6 months post-placement). RESULTS: The occlusal force of implant-supported prostheses was significantly (P = .000) lower than those of the control natural teeth at the baseline, then no significant difference was found with that of the mesial teeth at 3 months, and finally it was significantly (P = .000) lower than that of the distal teeth at 6 months; meanwhile, it significantly (P = .008) increased by a mean of 2.04 times from 2 weeks (3.39 ± 2.61%) to 3 months (6.90 ± 4.77%), whereas no significant difference (P = .900) was found from 3 months (6.90 ± 4.77%) to 6 months (7.31 ± 4.60%). In addition, the bite force of the posterior segment on the restored side of both unilateral and bilateral gaps was significantly (P = .013,.001) improved by 3.31% and 6.83%, respectively, although the discrepancy in bite force significantly (P = .039) increased from an initial 3.52% to 5.02% for subjects with bilateral defects, accompanying increases in the proportion (15.38%) of the level III bilateral bite force deviation (P >.05). CONCLUSIONS: Bite force and masticatory ability can be improved with the immediate delivery of a single posterior implant restoration. The bite force distributed on the implant prosthesis inevitably increases after placement of implant prostheses, a routine follow-up and occlusal evaluation are strongly needed.

The efficacy of bio-aerosol reducing procedures used in dentistry: a systematic review.

BACKGROUND AND OBJECTIVE: Bio-aerosols, are routinely generated and airborne in clinical dentistry due to the operative instrumentation within an oral environment bathed in salivary organisms. SARS-CoV-2 transmission being responsible for the current pandemic, appears through airborne aerosols and droplets, thus, there has been an intense focus on such aerosol-generating procedures, and their reduction. Hence the objective of this systematic review was to evaluate available data on three major measures: rubber dam application, pre-procedural oral rinse, and high-volume evacuators (HVE) aimed at reducing bio-aerosols. METHOD: PubMed via Ovid MEDLINE, EBSCO host, Cochrane Library and Web of Science databases were searched between 01 January 1985 and 30 April 2020. RESULTS: A total of 156 records in English literature were identified, and 17 clinical studies with 724 patients included in the final analysis. Eligible articles revealed the inadequacy of three principle approaches used in contemporary dental practice to minimize such bio-aerosols, rubber dam application, pre-procedural oral rinses, and HVE. The latter is an extremely effective method to reduce bio-aerosols in dentistry, although no single method can provide blanket cover. CONCLUSION: Present systematic review indicates that employing combination strategies of rubber dam, with a pre-procedural antimicrobial oral rinse, and HVE may contain bio-aerosols during operative procedures.

Effectiveness of bilayer porous polyethylene membrane for alveolar ridge preservation: A randomized controlled trial.

BACKGROUND: Porous polyethylene has been successfully used in several medical applications with good outcomes. Based on this, a new bilayer porous polyethylene membrane (B-PPM) was developed for possibly being used as a membrane in alveolar ridge preservation. PURPOSE: To evaluate the clinical efficacy of a new B-PPM in comparison to high-density polytetrafluoroethylene membrane (d-PTFE) in alveolar ridge preservation. MATERIALS AND METHODS: Thirty patients were randomized into two groups according to the membranes used to cover the socket (B-PPM or d-PTFE). Wound healing was monitored at day 1, 3, 7, 14, 28, and 4 months postoperatively. Dimensional changes of alveolar ridge were measured immediately after tooth extraction and at 4 months later using intraoral scanner and cone beam computed tomography. Bone cores were harvested before implant placement. Implant stability at insertion and prior to prosthesis delivery were also measured. RESULTS: No significant difference in socket wound closure between groups was observed excepting at day 14 that B-PPM showed a faster wound closure than d-PTFE (P = .03). Greater bone resorptions were seen on buccal than lingual side and on coronal than apical part of the alveolar ridge. No significant difference in dimensional changes of alveolar ridge, new bone formation, connective tissue content, residual bone grafts, and implant stability between two groups. CONCLUSION: B-PPPM was safe and effective for alveolar ridge preservation.

Evaluation of periodontally diseased molars in diabetics with Miller-McEntire Periodontal Prognostic Index.

AIM AND OBJECTIVE: The aim of this study was to prospectively determine and establish the periodontal prognosis of diseased molars in diabetic patients using the Miller-McEntire Periodontal Prognostic Index (MMPPI) with an additional criterion for diabetes (changes in glycosylated hemoglobin levels), at 2-year postperiodontal therapy. MATERIALS AND METHODS: A sample of 200 molars in 25 patients with diabetes mellitus (DM) and chronic periodontitis were evaluated. The prognostic parameters evaluated include age, probing depth (PD), mobility, furcation involvement, diabetes, and molar type. The total score calculated from all parameters was used considered prognosis score for each molar. All patients were evaluated at baseline and 2-year posttreatment. RESULTS: The results of this study suggest that following prognostic factors, DM (hazard ratio [HR] =5.2), age (HR = 0.4), and molar type (HR = 0.6) were clinically significant at the end of the 2-year posttherapy from baseline. A total of 4 (2%) teeth were extracted from the 200 teeth with a mean of 0.02 for the tooth lost during 2-year posttreatment. Significant improvements (P < 0.05) in the frequency PD, furcation, and mobility scores were noted at 2 years. CONCLUSIONS: These findings demonstrate that score for DM as prognostic criterion is a valid addition to MMPPI. The factors such as DM, age, and molar type can impact the prognosis of molar survival. Studies with a larger sample size and longer follow-up are required to affirm the findings of this preliminary study.

Prospective evaluation of periodontally diseased molars in smokers using the Miller-McEntire Periodontal Prognostic Index.

BACKGROUND: The purpose of this 2-year prospective survival analysis study is to determine a statistically validated periodontal prognostic score for diseased molars in smokers using the Miller-McEntire Periodontal Prognostic Index (MMPPI). MATERIALS AND METHODS: Two hundred molars were evaluated from 25 patients who were smokers with moderate-to-severe chronic periodontitis. The factors evaluated included age, probing depth, mobility, furcation involvement, smoking, and molar type. A modified, 5 level, scoring criterion for smoking based on smoking-dose was adopted. MMPPI was computed as the sum of scores for all six prognostic factors. Appropriate periodontal treatment and supportive periodontal therapy were provided. All patients were evaluated at baseline and 2 years posttreatment. Hazard risk ratio (HR) was computed for each prognostic factor. RESULTS: A total of 3 (1.5%) teeth of the 200 molars were extracted over the 2-year follow-up duration, with a mean of 0.015 teeth lost. The HR was found as significantly higher for three individual prognostic factors: mobility (HR = 5.57, P = 0.02), smoking (HR = 3.35, P = 0.04), and furcation involvement (HR = 7.30, P = 0.01). Significant and positive HR (HR = 1.70, P = 0.01) was noted for the total MMPPI score, validating its prognostic value for molar survival at 2 years prospectively. CONCLUSIONS: The findings of the current study demonstrate the prognostic validity of MMPPI incorporating a more detailed smoking score criterion. The factors smoking, furcation involvement, and mobility significantly impacted the likelihood of survival of periodontally diseased molars. Further studies with a larger sample size and longer follow-up are required to confirm these findings.

Efficacy of soft tissue augmentation around dental implants and in partially edentulous areas: a systematic review.

AIM: To review the dental literature in terms of efficacy of soft tissue augmentation procedures around dental implants and in partially edentulous sites. METHODS: A Medline search was performed for human studies augmenting keratinized mucosa (KM) and soft tissue volume around implants and in partially edentulous areas. Due to heterogeneity in between the studies, no meta-analyses could be performed. RESULTS: Nine (KM) and eleven (volume) studies met the inclusion criteria. An apically positioned flap/vestibuloplasty (APF/V) plus a graft material [free gingival graft (FGG)/subepithelial connective tissue graft (SCTG)/collagen matrix (CM)] resulted in an increase of keratinized tissue (1.4-3.3 mm). Statistically significantly better outcomes were obtained for APF/V plus FGG/SCTG compared with controls (APF/V alone; no treatment) (p < 0.05). For surgery time and patient morbidity, statistically significantly more favourable outcomes were reported for CM compared to SCTGs (p < 0.05) in two randomized controlled clinical trials (RCTs), even though rendering less keratinized tissue. SCTGs were the best-documented method for gain of soft tissue volume at implant sites and partially edentulous sites. Aesthetically at immediate implant sites, better papilla fill and higher marginal mucosal levels were obtained using SCTGs compared to non-grafted sites. CONCLUSIONS: An APF/V plus FGG/SCTG was the best-documented and most successful method to increase the width of KM. APF/V plus CM demonstrated less gain in KM, but also less patient morbidity and surgery time compared to APF/V plus SCTG based on two RCTs. Autogenous grafts (SCTG) rendered an increase in soft tissue thickness and better aesthetics compared to non-grafted sites.

Evaluation of a ß-calcium metaphosphate bone Graft containing bone morphogenetic protein-7 in rabbit maxillary defects.

BACKGROUND: Calcium phosphate-based materials have been widely used as bone substitutes and more recently are being exploited together with growth factors as bone tissue engineering scaffolds regulating cell behavior. The aim of this study is to evaluate the in vitro and in vivo response to a newly developed calcium metaphosphate (CMP) bone graft, with and without bone-stimulating growth factor. METHODS: Porous scaffolds of CMP were developed and extensively tested in vitro. Subsequently, CMP grafts with osteogenic protein-1 (OP-1) (test) and without OP-1 (control) were implanted into experimental rabbit maxillary bone defects. Animals were sacrificed at 2, 4, and 8 weeks, and samples were examined with microcomputed tomography (micro-CT) and processed for histomorphometric analysis. RESULTS: At 8 weeks, the scaffolds containing OP-1 induced greater bone formation (P = 0.018) than CMP alone, based on histomorphometric evaluation (percentage bone area: test: 57.1 ± 5.6; control: 49.4 ± 7.7) and micro-CT analysis (percentage bone volume density: test: 63.46 ± 5.61; control: 51.20 ± 6.71). Thus, these data indicated that both test and control CMP grafts showed a good degree of bone formation. Furthermore, the CMP materials showed signs of resorption from 4 weeks, and no graft materials were observed at 8 weeks. CONCLUSIONS: In vitro, the OP-1 loaded graft demonstrated a release profile and bioactivity over a 28-day period. In vivo testing confirmed enhanced bone formation of the OP-1 loaded graft after 8 weeks of healing.