Non-submerged Implants Research Articles

Comparative evaluation of submerged versus nonsubmerged dental implants - A prospective, clinico-radiographic, split-mouth study

Background: To minimize the risk of impaired osseointegration historically, it has been recommended to insert the implant into the bone (submerged implants) and to allow for submerged healing of 3-6 months in the lower and upper jaw, this conventional technique is advocated. The concept of nonsubmerged healing was introduced in 1988 in which gingival former was placed at the time of implant placement instead of cover screw. The treatment concept of nonsubmerged implant placement enables early implant loading, one surgical procedure only, and a reduced treatment period for the patients. Aim: The aim of this study was to compare clinical and radiographic outcomes of submerged and nonsubmerged implants. Materials and Method: A prospective split-mouth study of a minimum of 20 bilateral edentulous patients (total of 40 sites) was selected and randomly distributed in two groups: submerged and nonsubmerged implants. Patients were evaluated clinically and radiographically by assessing the patients on clinical parameters which included peri-implant probing depth, mucosal thickness, and width of keratinizing gingiva. Radiographic parameters were crestal bone height-distance between implant shoulder and alveolar crest compared from the bone level, on intraoral periapical. Results: Our results revealed that the marginal bone loss is statistically significant and has higher values in nonsubmerged implant protocol. All the other clinical parameters were statistically insignificant. Conclusion: The nonsubmerged implants have reduced the chairside time of the patient, but have a comparatively higher crestal bone loss. Our study concludes that whether it is submerged or nonsubmerged implant placement protocol, under an appropriate oral environment, proper implant selection and methodology both the treatment modalities provide an overall similar success rate.

COMPARATIVE EVALUATION OF CRESTAL BONE LOSS AROUND SUBMERGED AND NON-SUBMERGED IMPLANTS WITH DIFFERENT TYPES OF HEALING ABUTMENT DESIGNS - AN IN VIVO STUDY

Successful osseointegration is observed predictably for submerged implants requiring a two-stage procedure as well as for non-submerged implants characterized by one-stage surgical procedure. This study was aimed at evaluating and comparing crestal bone alterations around submerged and non-submerged implant radiographically. Total 45 patients aged between 20 to 50 years with missing mandibular posterior teeth were divided into 3 groups [Submerged implants (n=15), Non-submerged implants with anatomic healing abutment (n=15) and Non-submerged implants with esthetic healing abutment (n=15)]. Radiographic evaluation of mesial and distal marginal bone loss was done at 1 month and 3 months. Statistically significant differences were found between submerged dental implants and non-submerged dental implants with anatomical type of healing abutment designs (P < 0.001) and between the two non-submerged dental implant groups with different types of healing abutments (P < 0.001) at 1 month and 3 months. But there was no statistically significant difference between submerged dental implants and non-submerged dental implants with esthetic type of healing abutments (P > 0.05) at 1 month and 3 months. It was concluded from this study that bone resorption during the osseointegration period using the non-submerged technique varied significantly depending on the morphology of the healing abutment used. The non-submerged technique with an esthetic healing abutment produced an equally predictable outcome compared with the submerged technique.

Evaluation of soft tissue and crestal bone changes around non-submerged implants with and without a platelet-rich fibrin membrane: A randomized controlled clinical trial.

Platelet-rich fibrin (PRF) membranes are known to enhance wound healing after periodontal surgeries and dental implant procedures. The aim of the present study was to examine the effect of PRF on soft tissue healing and the crestal bone level (CBL) around non-submerged dental implants. A total of 40 patients, aged 20-60 years, with partially edentulous posterior mandibular sites were divided into 2 groups of 20 patients each: group I received non-submerged implants with a PRF membrane; and group II was treated with non-submerged implants alone. The examined parameters included the modified plaque index (mPI), the gingival index (GI), the width of keratinized tissue (WKT), the thickness of keratinized tissue (TKT), and CBL, assessed using digital intraoral periapical radiography (IOPA). All parameters were measured at baseline (immediately post-op), and at 3-month and 6-month follow-ups. In comparison with baseline, statistically significant increases in WKT and TKT were observed in both groups at 3 and 6 months post-op (p < 0.05). Also, significant gains were noted in group I vs. group II (p < 0.05). The CBL increased significantly in both groups at 3 and 6 months post-op (p < 0.05), with no remarkable differences from 3 to 6 months. A decreased CBL was observed in group I vs. group II at the 3- and 6-month intervals (p < 0.05). The PRF membrane enhances peri-implant tissue wound healing, with gains in soft tissue width and thickness around non-submerged implants.

Use of Connective Tissue Graft and Coronally Advanced Flap in Areas of Buccal Contour Concavities for Nonsubmerged Implant Placement.

There is a lack of scientific evidence concerning the best timing of soft tissue management around implants, as well as a divergence of topics concerning optimal procedures. The objective of this study is to evaluate the gain in buccal contour and soft tissue stability after a surgical technique combining nonsubmerged implant placement with submarginal connective tissue graft (CTG) and coronally advanced flap (CAF). Seven patients (4 males and 3 females) underwent surgery for transmucosal implant placement in partially edentulous areas showing mild to moderate buccal contour concavities using a technique combining CTG and CAF. The following parameters were evaluated: keratinized tissue height (KTH), soft tissue thickness (STT), and vertical soft tissue level (VSTL) at T0 (before surgery), T1 (6 months after surgery), T2 (12 months after surgery) and T3 (2 years after surgery). After two years, we observed an increase of 78.5% in buccal KTH, 64% in STT, and 24% in VSTL. No implant presented any sign of mucositis or bone loss. Non-submerged implant placement using an "envelope flap design" in addition to CTG and CAF is beneficial.

Dental implant failure rates with low insertion torque with a nonsubmerged surgical approach: A retrospective clinical study.

It is currently unclear if a low insertion torque (IT) should prompt a clinician to submerge the dental implant at time of placement. This study aimed to analyze implant failure rates and marginal bone loss (MBL) as a function of IT and surgical approach. A total of 197 patients who had received 295 Mozo Grau (MG) implants were included in this study. The healing of submerged or nonsubmerged implants was evaluated in regular IT (≥20-25 Ncm) or low IT (<20-25 Ncm) cases. Implant failure and MBL were evaluated before prosthesis placement and at 6 and 12 months after functional loading with generalized estimating equations. The overall 12-month implant failure rate was 4.8% (95% confidence interval [CI]: 2.7%-8.2%). When successful at 12 months, dental implants placed with low IT and nonsubmerging had the same MBL as implants dental implants placed with other approaches (mean difference=-0.02 mm; 95% CI -0.05 to 0.02). Low IT combined with nonsubmerging of the dental implant was associated with a 30-fold increased odds for dental implant failure (95% CI: 3.8-236.6). low IT and nonsubmerged healing was associated with a high failure rate.

Effect of Ti-Base Abutment Gingival Height on Maintenance of Crestal Bone in Thick Biotype Patients: A Randomized Clinical Trial with 1-Year Follow-up.

To determine the effect of 0.7- and 2.4-mm transmucosal abutment height titanium bases on the crestal bone stability and peri-implant soft tissue condition of bone-level implants with platform switching in patients with vertically thick soft tissues. Sixty bone-level platform-switched implants were placed in the molar and premolar regions of both arches in 60 patients. All epicrestally inserted nonsubmerged implants had a 4.1-mm diameter and, after osteointegration, were randomly allocated into two groups: (1) the short group, with a titanium base of 0.7-mm transmucosal abutment height, and (2) the high group with a 2.4-mm height. Monolithic zirconia restorations were fabricated for all implants. Parallel intraoral radiographs were obtained after the delivery of restorations (T1) and after 1 year (T2). Crestal bone levels and peri-implant soft tissue conditions were calculated for each implant. The significance level was set at α = .05. After 1 year, 55 patients were evaluated, with a mean bone loss of 0.6 ± 0.51 mm (median: 0.71, range: 0 to 2.09 mm) in the short group (23 patients) and 0.45 ± 0.59 mm (median: 0.65, range: 0 to 2.12 mm) in the high group (22 patients), showing no significant difference between groups (P = .168). A significant increase in marginal bone height was noted between the T1 and T2 time points in the short and high (P = .029 and .001, respectively) groups. The peri-implant soft tissue health parameters did not show statistically significant differences. Crestal bone stability after 1 year of follow-up around epicrestally placed platform-switched implants is not influenced by transmucosal abutment height, if the vertical soft tissue thickness is ≥ 3 mm.

The Association of the One-Abutment at One-Time Concept with Marginal Bone Loss around the SLA and Platform Switch and Conical Abutment Implants.

Objectives: Repeated abutment disconnection/reconnection may compromise the mucosal barrier and result in crestal bone level changes. The clinical significance of this phenomenon is not yet clear, as most studies on this topic are short-term. Therefore, the aim of the present study was to evaluate the influence of abutment disconnections and reconnections on peri-implant marginal bone loss over a medium-term follow-up period. Material and methods: Twenty-one patients (6 men and 15 women) with a mean age 66.23 ± 9.35 year at the time of implant placement were included. All patients who received two adjacent nonsubmerged implants were randomly assigned into one of the two groups: definitive multiunit abutments (DEFs) connected to the implant that were not removed (test group) or healing abutments (HEAs) placed at surgery, which were disconnected and reconnected 3–5 times during the prosthetic phase (control group). Peri-implant marginal bone levels (MBL) were measured through periapical X-rays images acquired immediately after the surgery (baseline), at 4–7 months immediately after prosthetic delivery, and at 1-year and 3-year follow-up visits. Results: No implant was lost or presented bone loss of more than 1.9 mm during the 3-year follow-up; thus, the survival and success rate was 100%. Peri-implant mucositis was noticed in 38.1% DEFs and 41.9% of HEAs at the 3-year follow-up assessment. At the end of 3 years, the MBL was −0.35 ± 0.69 mm for participants in the DEFs group and −0.57 ± 0.80 mm for the HEAs group, with significant statistical difference between groups. Conclusions: Immediate connection of the multiunit abutments reduced bone loss in comparison with 3–5 disconnections noted in the healing abutments 3 years after prosthetic delivery. However, the difference between the groups was minimal; thus, the clinical relevance of those results is doubtful.

Keratinized mucosa changes around one-stage implants: A prospective case series.

The need of an adequate band of keratinized tissue (KT) to maintain periodontal health around teeth as well as around implants has been a debated topic over many years but still no conclusions have been drawn. This prospective case series evaluates the changes undergone by the keratinized mucosa (KM) and the soft tissue volume around non-submerged implants before the prosthetic rehabilitation. A total of 40 patients were included. The primary outcome was to analyze the width of the KM at both buccal and lingual aspects compared to the pre-existing KT in the edentulous ridge only in mandibular (pre)molar area. The mucogingival line was marked with a surgical pen and an intra-oral scanner was used to take the impression of the implant area the day of the surgery (T0, baseline) and before the crown placement (T1, 3months). Buccal soft tissue volume was measured at 1, 3, and 5 mm apical to the healing abutment position and a comparison between T0 and T1 was performed. Student t-test was used according to the distribution of the data (Shapiro-Wilk). The mean KT width at baseline was 4.54 ± 1.31 mm at buccal side and 5.04 ± 1.88 mm at lingual side. After 3months, the mean KM values were 3.15 ± 1.03 mm and 3.72 ± 1.56 mm at the buccal and lingual aspects, respectively. The differences, 30.6% of KM reduction buccally and 26.1% of reduction lingually, were statistically significant for both sides. Within the limitations of this investigation, it was observed that the KM width from the baseline to the 3months follow up presented a significant dimensional change in both the buccal and lingual aspects, whereas buccal soft tissue volume showed an increase between baseline and follow up.

Effect of lack of plaque control after the surgical treatment of peri-implantitis at surfaces with different characteristics: an experimental study in dogs.

The aim of the present study was to evaluate the effect of the induction of peri-implantitis and of plaque accumulation on implants with different surface characteristics after the surgical treatment. All mandibular premolars and first molars were extracted bilaterally in six dogs. After 3months, two non-submerged implants were installed, each with either a hydrophilic sandblasted and acid-etched surface stored in saline solution (SLActive) or an acid-etched and modified with calcium ions surface (UnicCa). After 3months, ligatures were placed in the sulcus around the implants to induce an experimental peri-implantitis and plaque accumulation was allowed. After 3months, ligatures were removed and, after one more month of plaque accumulation, a surgical treatment was performed using gauzes soaked in saline and irrigations. X-rays were taken at this stage. Plaque control maintenance was established at the control sites, while plaque accumulation was allowed at the test sites (plaque sites). After 5months, biopsies were obtained. Marginal bone levels were compared between x-rays and histological assessments. At the time of peri-implantitis treatment, two SLActive implants were lost. At the euthanasia, seven more implants were lost only in the plaque group, one control and six test implants. The calculated mean values of the marginal bone level of the two surfaces at the treatment were 3.65 ± 1.71mm in the control group, and 3.65 ± 1.76mm in the plaque group (p = 0.463). The additional marginal bone loss after 5months from surgical treatment was 0.67 ± 0.67mm (UnicCa, 0.48 ± 1.06mm and SLActive, 0.79 ± 2.10mm) and 3.11 ± 1.38mm (UnicCa, 2.67 ± 1.87mm and SLActive, 3.94 ± 2.11mm) for the control and plaque groups, respectively (p = 0.028). The lack of plaque control after the surgical treatment of the peri-implantitis strongly influenced the marginal bone loss.

Immediate non-submerged implants with laser-microtextured collar placed in the inter-radicular septum of mandibular molar extraction sockets associated to GBR: Results at 3-year.

BackgroundThe aim of the present study was to radiographically evaluate the vertical socket walls changes, and the peri-implant marginal bone remodelling, and clinicallly the soft tissues conditions around the non-submerged single implants placed into the inter radicular septum of mandibular molar sockets, associated with a collagen membrane, after 3 years of loading. Material and MethodsThirty patients underwent to placement of a non-submerged implants with a laser-microtextured collar into the inter radicular septum of mandibular molar fresh extraction sockets. A collagen membrane and the mucoperiosteal flap were adapted around the neck of the implants, leaving the laser-microtextured collar to heal in a transmucosal fashion. ResultsAt the end of the follow-up period, no statistical differences were found for each radiographic measurements used for the examination of extraction sockets vertical bone changes. Compared to implants placement, at the end of the 3-year follow-up, the vertical radiographic mesial and distal peri-implant marginal bone levels showed a statistically significant gain of 0.9 (SD 0.5), and 1.0 mm (SD 0.6), respectively (P=0.037). Conclusions In mandibular fresh extraction sockets, the method of GBR around transmucosal implants with laser-microtextured surface placed into the interadicular septum may be used successfully to counteract the ridge remodelling. Key words:Non-submerged implants, GBR, laser-microtextured collar.

Clinical and radiographics results at 3 years of RCT with split-mouth design of submerged vs. nonsubmerged single laser-microgrooved implants in posterior areas

AimTo evaluate and compare radiographic crestal bone loss (CBL) and soft tissue parameters around submerged/two-stage and nonsubmerged/one-stage single implants with the same endosseous portion (body design and surface, thread design and distance) and identical intramucosal laser-microgrooved surface, after 3 years of loading.Materials and methodsTwenty submerged/two-stage implants and 20 nonsubmerged/one-stage implants were placed randomly with a split-mouth design in the posterior areas of 20 partially edentulous patients.Radiographic and clinical examinations were carried out at the implant placement, at the delivery of prosthetic restorations, and at each year of the follow-up period. Plaque index (PI), probing depth (PD), bleeding on probing (BOP), and gingival recession (REC) were recorded. Radiographic crestal bone levels were assessed at the mesial and distal aspect of the implant sites. In addition, the influence of the vertical keratinized tissue thickness (KTT) on CBL was investigated.ResultsAt the delivery of prosthetic restorations, a statistically significant difference (P = 0.013) was found in radiographic mean CBL between submerged and nonsubmerged implants (0.15 ± 0.05 mm vs. 0.11 ± 0.04 mm). At the end of the follow-up period, no statistical difference (P = 0.741) was found in the mean CBL between submerged and nonsubmerged implants (0.27 ± 04 mm vs. 0.26 ± 0.5 mm). The changes in the soft tissues including PI, PD, BOP, and REC had no significant differences in either group. Moreover, KTT did not show a statistical correlation with CBL.ConclusionsAfter 3 years of loading, no statistical difference was noted in CBL and soft tissue conditions between single submerged two-stage and nonsubmerged one-stage laser-microgrooved implants.Trial registrationhttp://clinicaltrials.gov/ct2/show/NCT03674762

Bone healing at non-submerged implants installed with different insertion torques: a split-mouth histomorphometric randomized controlled trial

ObjectivesTo evaluate histomorphometrically the healing at implants installed with standard or very low insertion torque valuesMaterial and methodsTwelve volunteer patients were recruited, and two screw-shaped titanium devices were installed in the distal segments of the mandible using insertion torque values of either < 10 Ncm or ~ 30 Ncm. The implants were left to heal in a non-submerged fashion. After 8 weeks, biopsies were retrieved, and ground sections were prepared for histological evaluation.ResultsHistological slides from 11 patients were available for (n = 11). The new bone in contact with the implant surface was 39.3 ± 18.5% and 49.4 ± 9.4% at the < 10 and ~ 30 Ncm sites, respectively. Considering the pre-existing old bone, the total mineralized bone was 46.8 ± 22.1% at the < 10 Ncm sites and 57.0 ± 14.1% at the ~ 30 Ncm. No statistically significant differences were found.New bone density and total mineralized bone density were 36.6 ± 8.1% and 53.0 ± 13.5% at the < 10 Ncm sites and 35.9 ± 10.0% and 52.2 ± 16.0% at the ~ 30 Ncm sites, respectively. No statistically significant differences were disclosed.ConclusionFrom the data of the present study, it can be concluded that a trend of higher osseointegration was observed at the ~ 30 Ncm compared to the < 10 Ncm torque group. Nevertheless, it can be concluded that an implant installed with a very low torque may achieve a good integration.Trial registrationClinicalTrials.gov NCT04017156; trial retrospectively registered on 12 July 2019.

Tapered Screw Implants With Different Machined Neck Designs: A 3-Year Split-Mouth Randomized Controlled Prospective Study.

Tapered Screw Implants With Different Machined Neck Designs: A 3-Year Split-Mouth Randomized Controlled Prospective Study.

Bone Healing at Non-submerged Implants Installed With Different Insertion Torques.

Bone Healing at Non-submerged Implants Installed With Different Insertion Torques.

Peri-implantitis at implants with different diameters: a pilot study in dogs

AimTo evaluate the progression of an induced peri-implantitis at implants with different diameters and the outcome of a corrective surgical debridement.MethodsThree months after the extraction of the mandibular premolars and first molars in six dogs, non-submerged narrow implants (3.3 mm in diameter) or standard implants (3.8 mm and 4.1 mm) were installed in the molar regions, bilaterally. After 3 months, peri-implantitis lesions were induced with ligatures and plaque accumulation for 3 months. Plaque accumulation was allowed for a further month after ligatures removal. A surgical mechanical decontamination of the surfaces was subsequently performed using gauzes soaked in saline and irrigation. Five months after, biopsies were retrieved and histological slides prepared. X-rays were taken at treatment and 5 months after.ResultsFourth months after peri-implantitis induction, 2.2 ± 1.0 mm at the standard implants and 3.2 ± 0.4 mm at the narrow implants were observed. Five months after treatment, a mean gain of marginal bone of 0.5 ± 0.6 mm was obtained at the standard implants and of 0.9 ± 0.4 at the narrow implants (p = 0.249). The vertical and horizontal defects were found partially closed. At the histological analysis, the coronal level of osseointegration after 5 months of healing was at 2.1 ± 0.8 mm at the standard implants, and 2.8 ± 0.3 mm at narrow implants (p = 0.116).ConclusionsIn conclusion, the narrow implants showed a tendency of a faster progression of the induced peri-implantitis compared to standard implants. The implant diameter did not influence the outcome of a surgical treatment of an induced peri-implantitis.

The effect of grafting the horizontal gap distance in non-submerged immediate single tooth implants on hard and soft tissues

The effect of grafting the horizontal gap distance in non-submerged immediate single tooth implants on hard and soft tissues

Smoking May Lead to Marginal Bone Loss Around Non-Submerged Implants During Bone Healing by Altering Salivary Microbiome: A Prospective Study.

This prospective and controlled study elucidates the impact of smoking on the salivary microbiome and its further influence on marginal bone loss (MBL) around an implant during a 3-month bone-healing period. Saliva samples were collected preoperatively from 20 periodontally healthy patients with single-tooth replacement in the posterior mandible (smokers [n = 10] and non-smokers [n = 10]). Sequencing of 16S recombinant RNA gene amplicons was used to characterize the salivary microbiome. Each patient received implant surgery after oral clinical assessment, and MBL around the implant was measured during a 3-month healing period. In total, 871,389 sequences were compared against the Human Oral Microbiome Database for bacterial identification. Microbial signatures of smokers exhibited lower diversity and richness, with a significant decrease in uncultured species. The phyla Gracilibacteria and Saccharibacteria showed a significant decrease in smokers. The genera Streptococcus, Lachnoanaerobaculum, Stomatobaculum, and Eubacterium were significantly increased in smokers, whereas Selenomonas, Selenomonas [G-3], and Catonella were significantly decreased. Specifically, Porphyromonas gingivalis was significantly more abundant in smokers, which was positively related to the severity of MBL during bone healing. Smoking shapes the salivary microbiome in states of clinical health, and further may influence MBL during bone healing by creating high at-risk-for-harm communities. Understanding of the distinctly divergent oral microbiome in smokers and non-smokers is a base for personalized therapeutics for this high-risk cohort and also a base for further study on the pathologic mechanisms.

Marginal bone loss around non-submerged implants is associated with salivary microbiome during bone healing

Marginal bone loss during bone healing exists around non-submerged dental implants. The aim of this study was to identify the relationship between different degrees of marginal bone loss during bone healing and the salivary microbiome. One hundred patients were recruited, and marginal bone loss around their implants was measured using cone beam computed tomography during a 3-month healing period. The patients were divided into three groups according to the severity of marginal bone loss. Saliva samples were collected from all subjected and were analysed using 16S MiSeq sequencing. Although the overall structure of the microbial community was not dramatically altered, the relative abundance of several taxonomic groups noticeably changed. The abundance of species in the phyla Spirochaeta and Synergistetes increased significantly as the bone loss became more severe. Species within the genus Treponema also exhibited increased abundance, whereas Veillonella, Haemophilus and Leptotrichia exhibited reduced abundances, in groups with more bone loss. Porphyromonasgingivalis, Treponemadenticola and Streptococcus intermedius were significantly more abundant in the moderate group and/or severe group. The severity of marginal bone loss around the non-submerged implant was associated with dissimilar taxonomic compositions. An increased severity of marginal bone loss was related to increased proportions of periodontal pathogenic species. These data suggest a potential role of microbes in the progression of marginal bone loss during bone healing.

Comparison of Marginal Bone Level Changes of Immediately Loaded Implants, Delayed Loaded Nonsubmerged Implants, and Delayed Loaded Submerged Implants: A Randomized Clinical Trial.

The aim of this randomized clinical trial was to radiographically compare peri-implant marginal bone level changes between immediately loaded implants without the removal of an abutment placed at the time of surgery (IL), delayed loaded nonsubmerged implants (NS), and delayed loaded submerged implants (SI). Patients' edentulous sites were randomly allocated to the three groups of implants so that each patient received one implant of each group. Digital periapical radiographs were obtained at baseline as well as three (T1), six (T2), and nine (T3) months after implant insertion. The mesial and distal bone crest levels adjacent to each implant were measured, and the mean values were calculated for each implant at each period. The data were statistically analyzed by repeated measures analysis of variance (ANOVA) and the Tukey test (P < .05). The patient sample comprised 15 subjects (13 women and 2 men; mean age: 47.7 years) with partially edentulous sites in the mandibular posterior area. Forty-five implants were inserted (15 IL implants, 15 NS implants, and 15 SI implants). There was no statistically significant difference between the three groups with regard to changes in the marginal bone level during the follow-up period. The study achieved a 93.3% cumulative survival rate for both delayed loaded groups (NS and IS) and a 100% survival rate for the IL group. In the 9-month period following the implants, no statistically significant differences were found between immediately and delayed loaded implants or between submerged and nonsubmerged implants in bone level changes in patients with partial posterior mandibular edentulism.

The effect of grafting the horizontal gap distance in non-submerged immediate single-tooth implants on hard and soft tissues

The effect of grafting the horizontal gap distance in non-submerged immediate single-tooth implants on hard and soft tissues