Preservation of esthetics with implant dentistry: a clinical report

Background: The replacement of single teeth with implants in the anterior maxilla poses a significant challenge to the clinician because of its esthetic implications. Purpose: The purpose of this article is to report a protocol in which single teeth are replaced by implants and temporarily restored without load, immediately after extraction. Materials and Methods: Between June 2001 and July 2002, 16 cases were followed up in which this protocol was used. Briefly, the teeth are extracted with a Periotome (Friadent, Mannheim, Germany), using a napless technique, the sockets are evaluated and débrided, an osteotomy is performed following the direction of the socket, and a tapered implant is placed using the alveolar crest as the landmark. A temporary abutment is immediately custom made, and a temporary crown is placed without loading. The 16 cases are summarized, and 4 of them are presented to illustrate this approach. Results: All four cases have provided excellent esthetic results maintaining an ideal implant‐to‐supporting‐tissue relationship. Furthermore, the overall time needed to restore the cases was considerably reduced when compared with time needed for the conventional approach. Conclusion: The four cases presented support the use of the described protocol in the placement of single implants in areas of the maxillary anterior region where esthetics is a high priority.     

Alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification: a three-dimensional microcomputed tomography analysis

Background: Previous studies assessed bone remodeling after a single tooth extraction; however, the effect of multiple contiguous teeth extractions around immediate implant remains unknown. The aim of this microcomputed tomographic investigation is to analyze the alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification (ESC). Methods: Under general anesthesia, 10 beagle dogs underwent atraumatic tooth extractions. Animals were randomly divided into three groups, with 16 sites per group: 1) ESC‐1, single tooth extraction; 2) ESC‐2, two contiguous teeth extraction; and 3) ESC‐3, more than two contiguous teeth extractions. Immediate implants were inserted in each socket, and postoperative plaque control measures were undertaken. After euthanasia, the jaw segments were evaluated for bone thickness, marginal bone loss (MBL), and bone‐to‐implant contact (BIC) using microcomputed tomography. Results: The mean buccal bone thickness (P <0.05) and MBL (P <0.05) was compromised in jaws in ESC‐3 compared to those in ESC‐1 and ESC‐2. The BIC was significantly higher among jaws in ESC‐1 compared to those in ESC‐2 and ESC‐3 (P <0.05). There was no significant difference in the buccal bone thickness, MBL, and BIC among the groups in the maxilla and mandible. Lingual bone remodeling did not reveal any significant differences among the groups in either jaw. Conclusion: Buccal bone remodeling is significantly more extensive around immediate implants placed in multiple contiguous tooth extraction sites compared to immediate implants placed in single tooth extraction sites.     

Experimental study on penetration of dental implants into the maxillary sinus in different depths

The exposing of dental implant into the maxillary sinus combined with membrane perforation might increase risks of implant failure and sinus complications.

Objective

The purpose of this study was to investigate the effects of the dental implant penetration into the maxillary sinus cavity in different depths on osseointegration and sinus health in a dog model.

Material and Methods

Sixteen titanium implants were placed in the bilateral maxillary molar areas of eight adult mongrel dogs, which were randomly divided into four groups according to the different penetrating extents of implants into the sinus cavities (group A: 0 mm; group B: 1 mm; group C: 2 mm; group D: 3 mm). The block biopsies were harvested five months after surgery and evaluated by radiographic observation and histological analysis.

Results

No signs of inflammatory reactions were observed in any maxillary sinus of the eight dogs. The tips of the implants with penetrating depth of 1 mm and 2 mm were found to be fully covered with newly formed membrane and partially with new bone. The tips of the implants with penetrating depth over 3 mm were exposed in the sinus cavity and showed no membrane or bone coverage. No significant differences were found among groups regarding implant stability, bone-to-implant contact (BIC) and bone area in the implant threads (BA).

Conclusions

Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant osseointegration in canine.     

Immediate implantation of a pure titanium implant into an extraction socket: report of a pilot procedure.

The conventional osseointegration protocol calls for waiting up to 12 months for ossification of an extraction socket to heal before placing an endosseous implant. In this study the possibility of placing a pure titanium implant directly into an extraction socket immediately after extraction was investigated. A pure titanium Nobelpharma 10-mm implant was placed into a central incisor extraction socket of a stump-tailed monkey and allowed to heal for a period of 6 months, followed by functional loading of the implant. The implant was osseointegrated on a clinical and histological level. This pilot study suggests that pure titanium implants have the potential to integrate when placed immediately after extraction of the teeth and warrants further investigation.     

Bone remodelling after regenerative procedures around implants placed in fresh extraction sockets: an experimental study in Beagle dogs

Introduction: After a tooth extraction, the height of the buccal wall tends to decrease. The literature indicates that regenerative techniques (guided bone regenerative [GBR] techniques) have succeeded in improving the bone levels. Therefore, this experiment set out to compare the physiological bone remodelling in Beagle dog models after implant placement in a fresh extraction socket, with and without the application of regenerative procedure. Materials and methods: Five dogs were used in this study. Test and control sites were randomly selected. The experimental teeth (fourth pre‐molar and first molar) were hemi‐sected removing the distal roots and placing implants. Porcine bone was placed to fill the gap around the implant on the test sites and a reabsorbable membrane was used to cover the area. The dogs were put down at different times (2 weeks, 1 month and 3 months). The measurements were taken immediately and at 2, 4, 12 weeks after implant placement. Student's test for paired data was used to compare the means of the clinical measurements. Results: At 2 weeks: On the control sites, few signs of resorption were detected at the first molar only, while at the test sites bone levels were placed at the implant shoulder or above. At 4 weeks: On the control site, slight bone remodelling was observed, while on the test site minor signs of resorption or an increase of bone levels were detected. At 12 weeks: The alveolar crest on the control sites showed various degrees of remodelling. On the test sites stable bone levels or an increase of bone crest was observed. Conclusion: With the limits of this study, the findings showed that GBR techniques were able to limit resorption of the alveolar crest after tooth extraction. A pattern of bone remodelling after tooth extraction and implant placement was observed in the control sites (no GBR) as well as in test sites (GBR), and although the exact cause of this is unclear, surgical trauma could play a role. Further studies are necessary to confirm these results and to clarify the precise causes of bone remodelling in fresh extraction sockets. To cite this article:
Barone A, Ricci M, Calvo‐Guirado JL, Covani U. Bone remodelling after regenerative procedures around implants placed in fresh extraction sockets: an experimental study in the Beagle dogs.
Clin. Oral Impl. Res. 22 , 2011; 1131–1137
doi: 10.1111/j.1600‐0501.2010.02084.x     

Flapless, CBCT-guided osteotome sinus floor elevation with simultaneous implant installation. I: radiographic examination and surgical technique. A prospective 1-year follow-up

Background: Survival rates of implants placed in transalveolar sinus floor augmentation sites are comparable with those placed in non‐augmented sites. Flapless implant surgery can minimize postoperative morbidity, alveolar bone resorption and crestal bone loss. The use of cone beam computerized tomography (CBCT) provides 3D presentations with reduced dose exposure. Objectives: To evaluate a flapless, CBCT‐guided transalveolar sinus floor elevation technique with simultaneous implant installation. Material and methods: Fourteen consecutive patients in need of maxillary sinus floor augmentation were enrolled in this study. Preoperative CBCT with a titanium screwpost as an indicator at the intended implant position was used to visually guide the flapless surgical procedure. Twenty one implants all with a length of 10 mm and a diameter of 4.1 and 4.8 mm were inserted and followed clinically and with CBCT for 3, 6 and 12 months postoperatively. Intraoral radiographs were taken for comparison. All patients were provided with permanent prosthetic constructions 8–12 weeks after implant surgery. Results: Ten (47.6%) implants were inserted in residual bone of 2.6–4.9 mm and 11 (52.3%) implants were inserted in residual bone of 5–8.9 mm. No implants were lost after surgery and follow‐up. There was no marginal bone loss during the follow‐up verified by CBCT. The implants penetrated on average 4.4 mm (SD 2.1 mm) into the sinus cavity and the mean bone gain was 3 mm (SD 2.1 mm). Conclusion: Flapless transalveolar sinus lift procedures visually guided by preoperative CBCT can successfully be used to enable placement, successful healing and loading of one to three implants in residual bone height of 2.6–8.9 mm. There was no marginal bone loss during the 3–12 months follow‐up. To cite this article :
Fornell J, Johansson L‐Å, Bolin A, Isaksson S, Sennerby L. Flapless, CBCT‐guided osteotome sinus floor elevation with simultaneous implant installation. I: radiographic examination and surgical technique. A prospective 1‐year follow‐up.
Clin. Oral Impl. Res. 23 , 2012; 28–34.
doi: 10.1111/j.1600‐0501.2010.02151.x     

Sinus floor elevation via the maxillary premolar extraction socket with immediate implant placement: a case series

Background: When immediate implant placement is considered for teeth with close proximity to the sinus floor, apical extension of the osteotomy is significantly limited, and often a staged approach is used. Implant placement into fresh extraction sockets and sinus floor manipulation using bone‐added osteotome sinus floor elevation with implant placement are techniques most often used independently or sequentially. Very few reports have described the combined use of immediate implant placement in fresh sockets and the bone‐added osteotome sinus floor elevation technique. Methods: We present five cases in which a maxillary premolar was extracted and an implant placed into the extraction site with simultaneous abfracture of the sinus floor using osteotomes. All teeth were extracted atraumatically, and sockets carefully debrided and checked for integrity of the walls. After ideal osteotomy preparation, particulate bone graft was placed in the osteotomy and appropriately sized osteotomes were used for sinus floor elevation. After sufficient elevation, implant placement was completed and particulate bone was packed in the bone–implant gap when indicated. Results: All implants were restored after a minimum healing period of 6 months. At the time of final restoration, bone was seen surrounding the implants from the apical portion to the most coronal thread. All five implants healed without complications and were in function for periods ranging from 6 to 12 months. Conclusions: Immediate implant placement with simultaneous osteotome sinus floor elevation is an advantageous combination of two successfully used techniques. This combined approach can significantly reduce the treatment time for implant therapy in teeth with close sinus proximity and provide the operator with the ability to place implants of desired length.     

Immediate implant placement: diagnosis, treatment planning and treatment steps/or successful outcomes

Diagnosis and treatment planning are key factors in achieving successful outcomes after placing and restoring implants placed immediately after tooth extraction. The efficacy of immediate implant placement has been established and shown to be predictable if reasonable guidelines are followed. Some or all of the following suggestions, depending on individual circumstances should be considered when evaluating a patient for dental implants: thorough medical and dental histories, clinical photographs, study casts, periapical and panogram radiographs, as well as a linear tomography or computerized tomography of the proposed implant sites. Reasons for tooth extraction include, but are not limited to, insufficient crown to root ratios, remaining root length, periodontal attachment levels, periodontal health of teeth adjacent to the proposed implant sites, unrestorable caries, root fractures with large endodontic posts, root resorption, teeth with deep furcation invasions being considered as abutments for fixed partial dentures, and questionable teeth in need of endodontic retreatment. Teeth requiring root amputations, hemisections or advanced periodontal procedures may have a questionable prognosis, and patients should be given the implant option before these procedures are implemented. Similarly, nonvital teeth, fractured at the gingival margin with roots shorter than 13 mm should be considered for the implant option. This review will describe the steps for immediate implant placement at the time of extraction as well as the "gap" and socket preservation.     

Experimental study on penetration of dental implants into the maxillary sinus at different depths

Objective

The purpose of this study was to investigate the effect of the dental implant penetration into the maxillary sinus cavity in different depths on implant and sinus health in a dog model.

Materials and methods

The study sample included eight titanium dental implant placed in four female dogs immediately after extraction of the first maxillary molar in the palatal socket and assigned into four groups according to the protruding of implant tips (control group A?=?0 mm, and study groups B, C, and D with protrusion of 1, 2, and 3 mm, respectively). The bone blocks of the implants were harvested 5 months postoperatively and evaluated by cone beam computed tomography (CBCT) and histological analysis.

Results

The whole groups showed no signs of inflammation during the 5-month period of the study. The tips of the implants in group B with penetrating depths of 1 mm were found to be fully covered with newly formed bone. The tips of the implants in group C with penetrating depths of 2 mm were exposed in the sinus cavity and showed partially new bone coverage, while depths of 3 mm in group D were found to have no bone formation and the dental implant fixture sites were communicated with the sinus cavity. No significant differences were found among the groups regarding implant stability.

Conclusion

Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant in canine.

     

Dental implant treatment with different techniques for sinus floor elevation--a case report

A 60-year-old man with missing maxillary molar teeth received dental implant therapy for reconstruction of occlusion. Sinus floor elevation with autogenous bone graft consisting of iliac bone block and particulate cancellous bone and marrow (PCBM) was performed in the bilateral maxillary sinuses for implant placement. On the right side, bone height in the molar region was less than 2mm. Therefore, a delayed protocol was applied, and 2 implants were placed 4 months after bone grafting. Bone graft resorption occurred during the healing period of 4 months. On the left side, 3 implants were placed simultaneously with sinus floor elevation, as bone height in the molar region was more than 4-5mm. The bone graft was carried out at the same time as implant placement. After implant placement, resorption of the bone graft stopped, and the superstructures were delivered on both sides. The tissues around the implants were clinically healthy at one year after examination. Sinus floor elevation with autogenous bone graft is an acceptable option for implant treatment in the maxillary molar region where there is adequate height of existing bone. In postoperative care, it is important to undertake adequate follow-up to ascertain occurrence of bone graft resorption.     

Microcomputed Tomographic Analysis of the Alveolar Ridge Alteration around Extraction Sites with and without Immediate Implants Placement: In Vivo Study

Background: The aim was to assess the alveolar ridge alteration around extraction sites with and without immediate implants according to extraction socket classification (ESC) using microcomputed tomography (micro‐CT). Material and Methods: Ten beagle dogs (mean age and weight: 24 ± 0.83 months and 13.8 ± 0.49 kg, respectively) were randomly divided into three groups according to the ESC. In Group 1 (ESC‐I), bilateral first and third premolars were extracted and replaced with immediate implants. In Group 2 (ESC‐II), two adjacent premolars were extracted with one immediate implant placement in the mesial socket in the maxilla and in the distal socket in the mandible. In Group 3 (ESC‐III), three adjacent teeth were extracted and an immediate implant was placed in the central socket. Primary closure was achieved using resorbable sutures. Buccal sites with dehiscence defects were excluded. After 4 months, subjects were sacrificed and alveolar ridge widths were measured at 1 mm interval in axial and sagittal views, using micro‐CT in sites with and without immediate implants. Results: In sites without immediate implant placement, alveolar ridge width was significantly higher in Group 1(6.1 ± 1.35 mm) than Group 3 (4.14 ± 1.53 mm) (p < .05). In sites with immediate implant placement, the alveolar ridge width was higher among sites in Group 1 (6.4 ± 3.8 mm) than Group 2 (4.8 ± 0.46 mm) (p < .05) and Group 3 (5.02 ± 0.84 mm) (p < .05). Overall, between each corresponding group in both sites with and without immediate implant placement at 1 mm thickness, there was no significant difference in the alveolar ridge widths. Conclusion: With the exception of Group 1 (ESC‐I), immediate implant placement did not prevent or minimize bone remodeling in extraction sites according to ESC.     

Extraction socket preservation graft before implant placement with calcium sulfate hemihydrate and platelet-rich plasma: a clinical and histomorphometric study in humans

Background: The aim of this investigation is to evaluate clinical and histologic outcome of using medical‐grade calcium sulfate hemihydrate (MGCSH) mixed with platelet‐rich plasma (PRP) for extraction socket preservation graft before implant placement. Methods: This study is a single‐site, randomized and controlled investigation. Sixteen patients with a non‐restorable tooth requiring extraction followed by implant placement were enrolled in this study. After extraction of a tooth, eight selected patients randomly received MGCSH mixed with PRP in the extraction sockets (test group), and eight selected patients randomly received collagen resorbable plug dressing material (control group). At the time of extraction and 3 months later (at implant placement surgery), vertical and horizontal socket dimensions were measured. Bone core samples were retrieved from the center of the healed socket before implant placement for histomorphometric analysis. Results: There was a statistically significant difference between the two groups based on histomorphometric analysis (P <0.05). New vital bone percentage regenerated after 3 months of healing was 66.5% ± 10.4% in sockets grafted with MGCSH mixed with PRP compared to 38.3% ± 9.3% collagen resorbable plug. There was no statistically significant difference in the amount of vertical and horizontal bone resorption (P >0.05) between groups. In all cases but two in the control group, implants were placed with primary stability. Conclusion: MGCSH mixed with PRP showed greater vital bone volume at 3 months with rapid enhancement of bone healing compared to PRP‐free collagen resorbable graft.     

Bilateral simultaneous augmentation of the maxillary sinus floor with particulated mandible. Report of a technique and preliminary results

This paper describes a surgical technique that permits the achievement of bilateral simultaneous augmentation of the maxillary sinus floor with the use of autologous bone harvested from the mandibular symphysis alone. Out of a group of 26 partially edentulous patients consecutively treated for sinus augmentation in an 18-month period, eight needed a bilateral procedure and were treated with the same surgical protocol. None of the patients had residual molar teeth, crestal bone height was reduced to 4 mm or less. Bone was harvested from the chin in blocks with a trephine bur, 11 or 9 mm in diameter, it was then particulated with a bone mill. Sinus augmentation and implant placement were done simultaneously in both sides of the maxilla. Implant-supported fixed partial dentures were inserted 6 months after the procedure. 44 ITI solid screw implants were placed in the grafted sinuses with a mean of 2.75 implants on each side. Mean follow-up was 19 months. In all patients needing a bilateral sinus lift, the procedure could be successfully completed. All implants were stable at abutment connection. All implants are stable at the latest follow-up, and all prosthesis are still working. In all implants, a clear bone-to-implant contact was visible. No peri-implant radiolucency has been noticed so far. It is concluded that bilateral augmentation of maxillary sinus floor with particulated mandible associated with simultaneous ITI implant insertion is feasible. It is a safe and effective procedure that can be accomplished in an out-patient environment with only minor discomfort for the patient.     

Survival of immediately loaded dental implants in deficient alveolar bone sites augmented with beta-tricalcium phosphate

PURPOSE: Dental implant placement in atrophic alveolar ridges often necessitates grafting procedures, followed by immediate or delayed implant placement. This study assessed the survival of immediately loaded dental implants placed in deficient alveolar bone sites at bone grafting. MATERIALS: From 1999 to May 2002, 1 operator (A.P.) inserted 1065 implants (607 in mandibles, 458 in maxillae) into 338 partially edentulous patients. Most implants were placed into compromised residual ridges or prepared tooth extraction sockets. Implants placed in augmented areas were splinted to implants in nonaugmented sites for stability. In all cases, beta-tricalcium phosphate was mixed with blood from the surgical site to augment the ridge level or fill spaces between the implant and socket wall. When indicated, the same materials were used for sinus floor augmentation. All implants were tapered screws with roughened surfaces, primarily (75%) from 1 manufacturer. One of the authors (Z.O.) prosthetically restored a total of 189 implants that were placed in 35 patients. In this group of patients, complete restorative data were available. All implants were monitored for 12-48 months (mean = 19.2; median = 24). RESULTS: A total of 1039 implants survived, and 26 failed, including 5 in the anterior mandible and 21 in the maxillae. In the restorative group, 186 implants survived, and 3 maxillary implants failed. All implant failures in this study occurred in the augmented sites. CONCLUSION: Within the limitations of this study, immediate loading of splinted implants in augmented sites is a predictable procedure.     

Simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement: A retrospective clinical study of 23 patients

ObjectiveThe aim of this study was to evaluate the efficacy of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement.Patients and methodsThe study patients (n = 23) were partially or completely edentulous in the posterior maxilla and required maxillary sinus augmentation. All included patients had a sinus pathology confirmed clinically and radiographically. The technique of simultaneous endoscopic endonasal sinus surgery and sinus augmentation was used in 15 patients, with eight endonasal sinus surgery procedures being performed 2–3 months before sinus augmentation. Where possible, implants were placed during the same surgical procedure (with a ridge bone height of at least 4 mm).ResultsThere were no any major intraoperative complications. Implants placed in the reconstructed areas were shown to integrate normally, and postoperative occlusal function and aesthetics were favorable. Of the 95 implants placed in these 23 patients, two failed to osseointegrate.ConclusionThe method of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement leads to a reduction in postoperative complications, significantly shortening the rehabilitation period for patients with maxillary sinus diseases and insufficient bone tissue.     

Sinus floor elevation via hydraulic detachment and elevation of the Schneiderian membrane

OBJECTIVES: Minor sinus floor elevation is a method with relatively high predictability but is technically demanding. Improvement of the technique and increase in the predictability are desirable. MATERIAL AND METHODS: A clinical protocol for minor sinus floor elevation with SLA-ITI (large grit acid-etched implants with diameter of 4.8 mm) is described. Using trephine instead of spiral burrs enables the harvesting of autogenous grafts from the implant socket and guarantees a perfect implant socket. The latter is necessary for optimal implant anchoring and for the hydraulic seal between socket and the osteotome. The whole allows a hydraulic detachment of the Schneiderian membrane, where the blood cushion gradually detaches and elevates the membrane, preventing its contact with the graft. RESULTS: Eight patients were successfully treated with the method described above. No membrane perforation occurred and an uneventful healing was observed in all patients. All implants were loaded prosthodontically 3 months after the implantation. CONCLUSIONS: The clinical protocol presented provides high predictability in clinical outcome, together with extremely low morbidity and shortened surgery.     

Implants with an Oxidized Surface Placed Predominately in Soft Bone Quality and Subjected to Immediate Occlusal Loading: Results from a 7‐Year Clinical Follow‐Up

Purpose: The purpose of this clinical follow‐up was to document the 7‐year outcome of immediately loaded implants exhibiting an oxidized surface. Material and Methods: Thirty‐eight patients received a total of 51 implant‐supported fixed prostheses. The restorations were supported by 102 implants, the majority of which were placed in posterior regions (88%) and primarily in soft bone quality (76%). Radiographic examinations were performed at prosthesis insertion, at 1‐ and 6‐month follow‐ups, and annually at the 1‐ through 5‐year follow‐up visits. Marginal peri‐implant soft tissue evaluations were conducted at all these follow‐ups. This report presents the results after at least 7 years of loading. Results: After 7 years of prosthetic loading, the cumulative implant survival rate was 97.1% and the mean marginal bone remodeling was ?1.51 mm (SD 1.00, n = 73) with significantly more initial remodeling at sites having received marginal guided bone regeneration procedures. A low rate of biological and technical complications was detected after 7 years of function. The quantification of intrasulcular plaque sampling showed no significant difference between teeth and implants. Conclusion: The 7‐year follow‐up data indicate that the introduced immediate loading protocol is a successful treatment alternative also including regions exhibiting soft bone conditions.     

Preferences of dental care providers in maintaining compromised teeth in relation to their professional status: implants instead of periodontally involved maxillary molars?

Aim: The purpose of this study was to evaluate the dentists' decision making in the maxillary molar region to find out how it is influenced by general practitioners' and specialists' characteristics as well as by the external evidence. Material and methods: A questionnaire was developed containing clinical cases and statements to assess practitioners' opinions on the treatment of periodontally involved maxillary molars and implant therapy with sinus grafting. Data were analysed with respect to the dentists' age and speciality. Results: Three hundred and forty questionnaires were evaluated (24% from universities, 76% from educational courses, overall response rate 35.1%). Forty six per cent of all participants indicated they had specialised, 52% placed dental implants, while 33% performed sinus grafting and 64% periodontal surgeries. Forty six per cent were against or were indecisive about having sinus grafting performed on themselves. The treatment proposals given for the clinical cases revealed a preference among older dentists and general practitioners for regenerative treatments even when these were not evidence based in through‐and‐through furcation involvements. Resective therapies were most often selected by periodontists. Prosthodontists tended to prefer more invasive treatment options with extractions and augmentations. More experienced general practitioners favoured conventional fixed dental prostheses in free‐end situations or no treatment rather than the complicated augmentation procedures, which were preferred by younger dentists. Conclusions: Implant placement seems to be widely accepted by almost all subjects, who may either place implants themselves or refer patients. More information seems to be needed on the indications for regenerative therapies for furcation involved maxillary molars, and guidelines required for decision making in complex clinical situations. To cite this article:
Zitzmann NU, Scherrer SS, Weiger R, Lang NP, Walter C. Preferences of dental care providers in maintaining compromised teeth in relation to their professional status: implants instead of periodontally involved maxillary molars?.
Clin. Oral Impl. Res. 22 , 2011; 143–150.
doi: 10.1111/j.1600‐0501.2010.02062.x     

Influence of placement depth on bone remodeling around tapered internal connection implant: a clinical and radiographic study in dogs

Background: The aim of this study is to evaluate the influence of placement depth on bone remodeling around implants with two different types of tapered internal implant–abutment interface (IAI): tapped‐in (TI) tapered internal IAI and screwed‐in (SI) tapered internal IAI in dogs. Methods: The second, third, and fourth premolars and the first molar in mandibles of six beagle dogs were extracted. After 8 weeks, two SI implants and two TI implants were placed in one side of the mandible. There were four experimental groups: 1) SI placed crestally (SIC); 2) TI placed crestally (TIC); 3) SI placed 1.5 mm subcrestally (SIS); and 4) TI placed 1.5 mm subcrestally (TIS). Healing abutments were connected 12 weeks after implant surgery. Implants and teeth were brushed every second day during the healing period. Clinical and radiographic parameters were recorded at 4, 10, and 16 weeks after second‐stage surgery. Results: Differences between SI and TI implants inserted in the same vertical position were not significant for peri‐implant probing depth (PD), clinical attachment level (CAL), or bone resorption (P >0.05). Subcrestal placement of both implants had greater PD and CAL compared to crestal groups. However, distance from IAI to the first bone–implant contact was lower in subcrestal groups compared to crestal groups (1.27 ± 0.42 mm for SIC versus 0.46 ± 0.26 mm for SIS, P <0.05; 1.36 ± 0.31 mm for TIC versus 0.78 ± 0.42 mm for TIS, P <0.05). Conclusions: Tapered internal IAI configuration had no significant effect on crestal bone resorption. Moreover, subcrestal placement of tapered internal IAI had a positive impact on crestal bone preservation around the cervix of the implant.     

Immediate provisional for single-tooth implant replacement with Brånemark system: preliminary report

Background: The success of osseointegrated implants ad modum Brånemark for single‐tooth restorations is documented. Future developments should aim at improving the benefits to patients by decreasing treatment time, minimizing surgical stages, and maximizing esthetic outcomes. Using knowledge from studies of immediate implant placement, one‐stage, immediate loading protocols, the authors developed the immediate provisional. Purpose: The purpose of this study was to develop a protocol to provide an immediate solution for restoring a single missing tooth in the esthetic zone. The protocol should be simple, predictable, cost effective, and allow the use of other techniques to improve esthetic outcome. Materials and Method: This prospective clinical study included 24 patients treated from August 1999 to October 2000. Single‐tooth implant replacement was done according to immediate provisional protocol. Thirteen of the 24 patients had immediate implant placement after tooth extraction. All implants were placed in the esthetic zone. During surgery, emphasis was placed on obtaining primary stability by achieving bicortical anchorage and maximum insertion torque of at least 40 Ncm. CeraOne (Nobel Biocare) abutments were used, and provisional crowns were fabricated immediately before wound closure. The occlusion was protected by adjacent teeth. Results: Within the follow‐up period of between 1 month and 15 months, all fixtures in the 24 patients were stable. Crestal bone loss greater than one thread‐width was not detected. The esthetic result was considered satisfactory by all patients. Conclusions: The implant placement and restoration protocol used in this study showed promising initial results for both the immediate implant and healed extraction site groups. The desirable goals of patient satisfaction, excellent esthetic outcomes, and no increase in treatment cost were achieved in this protocol. Further studies to elucidate the potential of the immediate provisional protocol are justified.