Changes in periodontal tissue and denture around the implants in the mandibular milled-bar implant overdenture: A 12-year follow-up / 대한치과보철학회지

The mandible has a smaller support area than the maxilla, and in particular, in patients with generalized alveolar bone resorption, the stability of the denture and the masticatory efficiency are significantly low in the case of conventional complete denture, due to the movement of the tongue and mandible. In these patients, implant overdenture is evaluated as a highly predictable treatment method with high retention and stability, and excellent pronunciation and masticatory force. In this clinical case, patient had an edentulous maxilla and generalized alveolar bone resorption in mandible. Therefore, complete denture was placed in the maxilla and implant overdenture using milled bar attachment on 4 implants was placed in the mandible. During the 12-year follow-up period, changes in periodontal tissue and denture around the implants were periodically managed and observed.

A clinical report of hybrid telescopic double crown denture with friction pin in a failed double crown denture case / 대한치과보철학회지

In removable partial dentures, many types of retentive systems have been studied and applied in clinical treatment. One of those systems is the double crown denture system which is widely used in European countries such as Germany and Sweden. Telescopic double crown dentures have several advantages such as convenience in maintaining oral hygiene, enabling to transfer occlusal force along the long axis of the abutment, and secondary splinting effect between the abutments which leads to higher clinical performance compared to conventional removal partial dentures. In this clinical case, the patient was initially restored with a maxillary hybrid telescopic double crown denture with friction pin using remaining natural teeth as abutments. After 7 years, due to lack of recall check-up and poor oral hygiene, the abutment teeth were affected by periodontitis and 4out of 5 of the abutment teeth had to be extracted. 3 additional implants were placed and the original abutment tooth with the inner crown was maintained. The mandible had fixed prostheses including implants but nevertheless, with strategic implant placement, the patient adapted well and was satisfied with the new maxillary tooth-implant combined double crown denture.

A clinical report of hybrid telescopic double crown denture with friction pin in a failed double crown denture case / 대한치과보철학회지

In removable partial dentures, many types of retentive systems have been studied and applied in clinical treatment. One of those systems is the double crown denture system which is widely used in European countries such as Germany and Sweden. Telescopic double crown dentures have several advantages such as convenience in maintaining oral hygiene, enabling to transfer occlusal force along the long axis of the abutment, and secondary splinting effect between the abutments which leads to higher clinical performance compared to conventional removal partial dentures. In this clinical case, the patient was initially restored with a maxillary hybrid telescopic double crown denture with friction pin using remaining natural teeth as abutments. After 7 years, due to lack of recall check-up and poor oral hygiene, the abutment teeth were affected by periodontitis and 4out of 5 of the abutment teeth had to be extracted. 3 additional implants were placed and the original abutment tooth with the inner crown was maintained. The mandible had fixed prostheses including implants but nevertheless, with strategic implant placement, the patient adapted well and was satisfied with the new maxillary tooth-implant combined double crown denture.

Prosthetic treatment for patient with anterior overbite and partial edentulism using maxillary hybrid telescopic double crown RPD and mandibular fixed prostheses: A 11-yr follow-up / 대한치과보철학회지

The biomechanical prognosis of conventional removable partial denture is questionable in case of patient with few remaining teeth or periodontally compromised teeth. In this case, hybrid telescopic double crown RPD may be a successful treatment alternative. Hybrid telescopic double crown RPD has following advantages over conventional RPD: secondary splinting effect between abutments, more vertical stress direction and more convenient in repairing the denture after extraction of abutment tooth. In this clinical case, patient had deep overbite in anteriors and partially edentulous. The maxilla was restored with hybrid telescopic double crown RPD and the mandible was restored with implants and fixed prostheses. Long-term follow-up and supportive periodontal treatment were performed, and satisfactory results were achieved in terms of function and aesthetics.

Clinical outcomes of rigid and non-rigid telescopic double-crown-retained removable dental prostheses: An analytical review

PURPOSE: The objective of this literature review was to analyze the cumulative survival rates (CSRs) of rigid and non-rigid double-crown-retained removable dental prostheses.MATERIALS AND METHODS: Screening of the literature published from January 1995 to December 2019 was performed by using electronic data base (Pubmed) and manual search. The CSRs of rigid and non-rigid double crown removable dental prostheses were investigated.RESULTS: A total of 403 articles were reviewed and 56 relevant articles of them were selected. Subsequently, 25 articles were included for data extraction. These articles were classified according to rigid and non-rigid type double crowns and further subdivided into teeth, implants, and teeth-implant combination types. The CSRs of rigid type double crown ranged from 68.9% to 95.1% of 5 to 10 years in tooth abutments, 94.02% to 100% over a 3-year mean observation periods in implant abutments, and 81.8% to 97.6% in tooth-implant combination. Non-rigid type double crowns had various CSR ranges from 34% to 94% maximum during 10 years observation in teeth abutment. The CSRs of non-rigid type had over 98% in implant abutments, and ranged from 85% to 100% in tooth-implant combination.CONCLUSION: The CSRs of double crowns varies according to types. With accurate evaluation of the remaining teeth and plan of the strategic implant placement, it could be successful treatment alternatives for partially or completely edentulous patients.

Prosthetic treatment for Down's syndrome patient with dental cross bite problem using maxillary double crown denture / 대한치과보철학회지

Patients with Down's syndrome have several dental complications such as small teeth caused by underdevelopment of dentin and enamel, periodontitis, agenesis of teeth, prolonged retention of primary teeth and malocclusion due to narrow palate. Removable denture with maxillary double crowns would be a good treatment option to solve the problems of the patient with Down's syndrome. Double crowns compensate the insufficient support and retention of denture and easily solve the cross bite problem. Double crowns also allow easy repair of denture in case of abutment teeth extraction. In this case, 26-year-old female patient with Down's syndrome and dental phobia had small number of teeth with enamel hypoplasia, prolonged retention of primary teeth and dental cross bite. Prosthetic treatment was done using removable denture with double crowns in the maxilla. In the mandible, teeth preparation was done on enamel margin without anesthesia. Anterior laminate and posterior complete zirconia crown restorations were performed. As a result, the cross bite was effectively corrected by denture with double crowns. Pronunciation and appearance were also improved without extraction of teeth and dental anesthesia.

Prosthetic treatment for patient with congenital bilateral cleft lip and palate to close oro-nasal communication using maxillary double crown and clasp retained removable denture / 대한치과보철학회지

Patients with cleft lip and palate have several problems such as oro-nasal communication, dental cross-bite caused by the insufficient growth of maxilla, poor pronunciation and esthetic problem. Removable denture with maxillary double crown near cleft palate and with clasp in the posterior teeth was used to solve the problems of the patient with cleft lip and plate. Double crowns make up for the insufficient mucosal support caused by the mucosa and alveolar bone loss in cleft lip and palate. Double crowns also allow easy repair of denture in case of abutment teeth extraction. In this case, 55-year-old female patient had bilateral cleft lip and palate and few remaining teeth on anterior maxilla. Prosthetic treatment was done for patient with bilateral cleft lip and palate to close oro-nasal communication using maxillary double crown and clasp retained removable denture. As a result, oro-nasal communication was effectively closed and the cross-bite was easily corrected by double crown and clasp retained denture. In addition, pronunciation and appearance were also improved.

The effect of periodontal and prosthodontic therapy on glycemic control in patients with diabetes

PURPOSE: To evaluate the effect of periodontal and prosthodontic therapy on glycated hemoglobin A(HbA1c) level in patients with diabetes. MATERIALS AND METHODS: This is a retrospective study of 70 patients suffering from diabetes who visited the Kyungpook National University Hospital between January 2016 and May 2018. Patients underwent medical evaluation for their routine check-up, which includes laboratory test for HbA1c levels. Among the 70 patients, 35 patients also visited Kyungpook National University Dental Hospital during the same period to receive periodontal and prosthodontic therapy, while the other 35 patients did not receive such therapy. The HbA1c levels were compared before and after periodontal and prosthodontic therapy. Comparisons between groups and within groups were performed using independent t-test. RESULTS: The HbA1c levels in the group who have received periodontal and prosthodontic therapy decreased from 7.2 to 6.7 (P=.001). The HbA1c levels in the control group decreased from 7.2 to 7.1 (P=.580). The difference in changes between the two patient groups was statistically significant (P=.011). CONCLUSION: Periodontal and prosthodontic therapy can be effective on glycemic control in patients with diabetes.

Maxillary anterior prosthetic treatment concerning anterior guidance of a patient who lost stable holding contact / 대한치과보철학회지

Recently, many patients undergo anterior prosthetic treatment for esthetic reasons. In some patients complain about functional reasons such as inaccurate pronunciation and occlusal discomfort after the treatment. Anterior teeth are important esthetically but in the occlusal point of view, anterior guidance is the second most important factor in occlusion, next to centric relation. Failure to determine an appropriate anterior guidance might lead to posterior occlusal interference, which can highly affect the stability of the posterior teeth. Also, discomfort might occur if the customized interior guidance is not in harmony with the patient's envelope of function. The patient in this case complained of overall discomfort in the maxillary anterior area after prosthetic treatment. The expressed difficulty in pronunciation, unstable occlusion due to lack of stable holding contact and discomfort of the facial muscles. Maxillary anterior prostheses were refabricated through systematic diagnosis and treatment and thus, this case presents esthetical and functional satisfaction to both the patient and the dentist.

Precision of the milled full-arch framework fabricated using pre-sintered soft alloy: A pilot study

PURPOSE: This study aimed to evaluate the marginal discrepancy of full-arch frameworks in implant-supported prostheses fabricated using pre-sintered soft alloy (PSA). MATERIALS AND METHODS: Full-arch metal frameworks were fabricated on the edentulous implant model using casting alloy (CA), fully-sintered hard alloy (FHA), and PSA (n = 4 in each group). To evaluate the misfit of the framework to the abutments, the absolute marginal discrepancy (AMD) values of the frameworks were measured in cross-sectional images that had been drawn as part of the triple-scan protocol. The AMD values were compared among the tested alloy groups using the Kruskal-Wallis test, with a post hoc Mann-Whitney U test (α=.05). RESULTS: The FHA and PSA groups showed lower marginal discrepancies than the CA group (P < .001). However, the FHA group did not differ significantly from the PSA group. CONCLUSION: Soft alloy milling is comparable to hard alloy milling, and it is more precise than casting in terms of the marginal fit of implant-supported, full-arch prostheses.

Causes of failures of long-term used double crown denture and new rehabilitation with dental implant and tooth combined denture using remaining teeth and implants / 대한치과보철학회지

Hybrid telescopic double crown have ever been good treatment option for patient with periodontally unfavorable few remaining teeth for successful prognosis. Tooth and implant combined telescopic double crown can be used for improving retention and support for denture with strategically placed implants on edentulous ridge. In this case, an 55-year-old female patient had chronic periodontitis with few remaining teeth on maxilla and fixed partial prosthodontics on mandible. Treatment of hybrid telescopic double crown with friction pin lasted 9.5 years only with natural teeth. After 9.5 years, additional implants was installed due to fracture of cast-posted abutment teeth. After implantation, tooth and implant combined double crown had fabricated. Through re-treatment, no complications of new denture has been found during 2 years follow up. This case presents fair prognosis of tooth and implant combined double crown denture in periodontally unfavorable condition.

Causes of failed implant attachments and application of double crown implant overdenture in one patient / 대한치과보철학회지

In this case, the patient was restored with gold Hader bar mandibular implant overdenture using two implants about 10 years ago, and the retentive force was lost due to severe wear of the bar due to 3.5 years use. The overdenture was repaired using a Locator attachment, but the male part was completely worn after 6.5 years use. Finally, we used a hybrid telescopic double crown with a friction pin to fabricate a new implant overdenture, which was observed for 2 years and showed excellent prognosis. So, we describe the cause of failure of each attachment (Gold Hader bar, Locator) in two implant overdentures and report on the advantages and disadvantages of double crown implant overdenture and the conditions for success.

Prosthetic rehabilitation for patient with hemi-maxillectomy: Obturator combined with a hybrid telescopic double crown using friction pin

When oral cancer develops in the maxilla, oro-nasal communication occurs after surgical treatment including removal of the primary site. Restoration through an obturator is necessary to prevent food from storing due to non-oral opening, and to ensure proper pronunciation and aesthetic restoration. In this case, the patient was treated with right hemi-maxillectomy due to oral cancer and has residual abutment and poor periodontal support due to the effect of head and neck radiotherapy. The obturator was treated with a hybrid telescopic double crown denture. Reporting a successful prognosis in 18 months of follow-up.

Long-term evaluations of teeth and dental implants during dental maintenance period

PURPOSE: This study was designed to evaluate the teeth and dental implants during dental maintenance therapy over 3 years in different conditions after periodontal and dental prosthetic treatment. MATERIALS AND METHODS: 166 patients received maintenance therapy. 59 patients were treated with 2% minocycline-HCl ointment as local drug delivery (LDD) (L group) and 107 patients were treated without LDD (NL group). Clinical data was collected in maintenance period for evaluation. Patients were classified into groups depending on the application of LDD with maintenance therapy, the type of dental treatment before maintenance period (Pre-Tx), the frequency (F-MT), and regularity (R-MT) of maintenance therapy. RESULTS: The numbers of lost teeth (N-teeth, P=.003) and newly placed dental implants (N-implants, P=.022) are significantly different according to Pre-Tx. F-MT among patients who received surgical dental treatment before maintenance period showed statistical differences in N-teeth (P=.041), but not in N-implants (P=.564). All of the patients in L group showed high F-MT (F-MT1). In NL group, there were no statistical differences in N-teeth or N-implants according to F-MT or R-MT. In F-MT1 group, application of LDD made N-teeth significantly different from both Pre-Tx groups while no significant difference could be found in N-implant. Independent t-test and one-way ANOVA were selected for statistical analysis. CONCLUSION: The regular maintenance therapy and LDD can be effective for teeth during maintenance period. It is not only pharmacological efficacy in decreasing bacterial species that makes LDD a useful adjunct. Application of LDD also motivates patients to take adequate check-ups in the aspects of both frequency and regularity.

Long-term evaluations of teeth and dental implants during dental maintenance period

PURPOSE: This study was designed to evaluate the teeth and dental implants during dental maintenance therapy over 3 years in different conditions after periodontal and dental prosthetic treatment. MATERIALS AND METHODS: 166 patients received maintenance therapy. 59 patients were treated with 2% minocycline-HCl ointment as local drug delivery (LDD) (L group) and 107 patients were treated without LDD (NL group). Clinical data was collected in maintenance period for evaluation. Patients were classified into groups depending on the application of LDD with maintenance therapy, the type of dental treatment before maintenance period (Pre-Tx), the frequency (F-MT), and regularity (R-MT) of maintenance therapy. RESULTS: The numbers of lost teeth (N-teeth, P=.003) and newly placed dental implants (N-implants, P=.022) are significantly different according to Pre-Tx. F-MT among patients who received surgical dental treatment before maintenance period showed statistical differences in N-teeth (P=.041), but not in N-implants (P=.564). All of the patients in L group showed high F-MT (F-MT1). In NL group, there were no statistical differences in N-teeth or N-implants according to F-MT or R-MT. In F-MT1 group, application of LDD made N-teeth significantly different from both Pre-Tx groups while no significant difference could be found in N-implant. Independent t-test and one-way ANOVA were selected for statistical analysis. CONCLUSION: The regular maintenance therapy and LDD can be effective for teeth during maintenance period. It is not only pharmacological efficacy in decreasing bacterial species that makes LDD a useful adjunct. Application of LDD also motivates patients to take adequate check-ups in the aspects of both frequency and regularity.

An alternative impression technique based on McLean's functional impression concept / 대한치과보철학회지

In this case report, an alternative impression technique for fabricating removable partial dentures was used in a patient with very few remaining teeth. In this technique, an individual tray was made on the cast, which was made by relining interim denture and taking overimpression with irreversible hydrocolloid according to McLean's functional impression concept. This method showed the following advantages: the no need for border molding with modeling compound, time saving for denture impression without overextension and accurate seating of the individual tray.

Assessment of the fit of zirconia-based prostheses fabricated with two different scan methods / 대한치과보철학회지

PURPOSE: This research was conducted to compare the marginal and internal fit of zirconia prostheses fabricated with the model scan method and the intraoral scan method. MATERIALS AND METHODS: In this study, 20 extracted human mandibular first molar was used in the preparation of abutment tooth for the fabrication of zirconia prostheses. In the first group, the model scan method was applied on 10 prepared teeth. In the other group, the intraoral scan method was used on other 10 prepared teeth. Datum of both groups were transmitted to the software system. Afterwards, 20 zirconia prostheses were fabricated using the Ceramill system. Weight technique was used to evaluate the internal gap of the zirconia prostheses. In the Replica technique, marginal gap of the zirconia prostheses were analyzed by optical microscopy. Statistical analysis was based on one-way ANOVA. RESULTS: Model scan group showed lower average weight than intraoral scan group when weight technique was applied, which has significance (P < .05). Also, model scan group showed significantly lower figures in all 5 measurements of replica technique than intraoral scan group (P < .05). CONCLUSION: Zirconia prostheses of both groups demonstrated clinically acceptable margin and internal fit. However, model scanned zirconia prostheses showed higher marginal and internal fit than intraoral scanned crowns.

Maxillar implant-retained overdenture using CAD/CAM milled zirconia bar with PEKK sleeve: a case report

The object of this case report is to introduce milled zirconia bar and PEKK female part made by CAD/CAM technology for bar attachment implant supported overdenture in maxillary edentulous patients. For over 2 years, in terms of function and esthetics, satisfactory result was obtained. Esthetically and functionally satisfactory results were obtained in periodic follow up check.

Treatment of the cleft lip and palate patient with few remaining posterior teeth using hybrid telescopic crown denture

For individuals with cleft lip and palate, the removable partial dentures (RPDs) have been an important treatment option. Some modifications from conventional prosthetic treatment may be necessary to achieve satisfactory functional and esthetic results in cleft patients. In case of cleft palate patient with periodontally compromised and only posterior few remaining teeth, removable partial prosthesis connected to telescopic crown can be the alternative treatment option. When connected to the RPD, telescopic crowns increase the prosthetic stability and retention, optimize favorable force transmission to the long dental axis, and improve esthetics. And the cross arch stabilization of double crown denture helps to stabilize both divided maxillary ridges in CLP patient. This case present one adult CLP patient using an RPD connected with hybrid telescopic crowns with friction pins to improve not only retention and stability but also aesthetics.

Comparison of the fit accuracy of zirconia-based prostheses generated by two CAD/CAM systems

PURPOSE: The purposes of this study are to evaluate the internal and marginal adaptation of two widely used CAD/CAM systems and to study the effect of porcelain press veneering process on the prosthesis adaptation. MATERIALS AND METHODS: Molar of a lower jaw typodont resin model was prepared by adjusting a 1.0 mm circumferential chamfer, an occlusal reduction of 2.0 mm, and a 5° convergence angle and was duplicated as an abrasion-resistant master die. The monolithic crowns and copings were fabricated with two different CAD/CAM system-Ceramil and Zirkonzahn systems. Two kinds of non-destructive analysis methods are used in this study. First, weight technique was used to determine the overall fitting accuracy. And, to evaluate internal and marginal fit of specific part, replica technique procedures were performed. RESULTS: The silicone weight for the cement space of monolithic crowns and copings manufactured with Ceramil system was significantly higher than that from Zirkonzahn system. This gap might cause the differences in the silicone weight because the prostheses were manufactured according to the recommendation of each system. Marginal discrepancies of copings made with Ceramil system were between 106 and 117 µm and those from Zirkonzahn system were between 111 and 115 µm. Marginal discrepancies of copings made with Ceramil system were between 101 and 131 µm and those from Zirkonzahn system were between 116 and 131 µm. CONCLUSION: Marginal discrepancy was relatively lower in Ceramil system and internal gap was smaller in Zirkonzahn system. There were significant differences in the internal gap of monolithic crown and coping among the 2 CAD/CAM systems. Marginal discrepancy produced from the 2 CAD/CAM systems were within a reported clinically acceptable range of marginal discrepancy.