Reappraisal of the removable partial denture as a treatment option for the shortened dental arch

Action of chitosan-based solutions against a model four-species biofilm formed on cobalt-chromium and acrylic resin surfaces

OBJECTIVE

To evaluate the anti-biofilm action of chitosan, nanoparticulate chitosan, and denture cleanser Nitradine™ against biofilms comprising Candida albicans, Candida glabrata, Staphylococcus aureus, and Streptococcus mutans.

BACKGROUND

Biofilm removal from removable partial dentures (RPD) is important for success in prosthetic rehabilitation.

MATERIALS AND METHODS

The anti-biofilm action of the experimental chitosan-based solutions and Nitradine™ was evaluated on acrylic resin and cobalt-chromium alloy through assessing cell viability, cell metabolism, residual aggregated biofilm, and extracellular polymeric substance and biofilm morphology.

RESULTS

Only chitosan reduced the viability of C. albicans on cobalt-chromium alloy surface, by 98% (a 1.7 log10 reduction in cfu). Chitosan-based solutions neither promoted substantial alteration of the metabolic activity of the four-species biofilm nor reduced the amount of the aggregated biofilm. After immersion in chitosan and nanoparticulate chitosan, viable microorganisms and extracellular polymeric substances distributed over the entire specimens' surfaces were observed. Nitradine™ reduced the viability and metabolic activity of biofilm grown on both surfaces, but it did not remove all aggregated biofilm and extracellular polymeric substances. After immersion in Nitradine™, approximately 35% of the specimens' surfaces remained covered by aggregated biofilm, mainly composed of dead cells.

CONCLUSION

Although chitosan and Nitradine™ promoted changes in the viability of microorganisms, neither solution completely removed the four-species biofilm from the Co-Cr and acrylic resin surfaces. Thus, isolated use of hygiene solutions is not indicated for biofilm control on RPDs; this requires complementary mechanical removal.

Force exerted on maxillary anterior teeth in mandibular unilateral and bilateral distal extension partial edentulous situation

The purpose of this study was to determine the influence of mandibular unilateral and bilateral distal extension partial edentulous situation and the use of removable partial dental prostheses on the force exerted on maxillary anterior teeth. A commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular distal extension edentulous situation were prepared and a distal extension removable partial dental prosthesis to replace missing posterior teeth was fabricated. The occlusal force was measured by inserting an occlusal force measuring film between the maxillary and mandibular teeth of the model. An occlusal load was applied and the forces and ratios were compared using the Kruskal-Wallis test and the Mann-Whitney U test (p < 0.05). As a result, the force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased in unilateral and bilateral edentulous situation. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial dental prosthesis. It is concluded that when the number of remaining teeth decreases in mandibular unilateral and bilateral distal extension partial edentulous situation, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular distal extension partial edentulous situation, using a removable partial dental prosthesis is effective in preserving the remaining teeth by reducing excessive force.

Quality of communicating design features for cobalt chromium removable partial dentures in Riyadh, Saudi Arabia

Purpose:

This survey aimed to investigate quality of communicating design features for the construction of cobalt chromium removable partial dentures (RPDs) among dentists in Riyadh, Saudi Arabia.

Materials and methods:

A survey of nine commercial dental laboratories located in Riyadh was carried out. In each visit, master casts for cobalt chromium RPDs and dentists’ prescriptions were examined. A quality score for the provided instructions was developed and ranged from 0 to 4. A zero score means that no instructions were sent from the dentist for the design of the RPD. A score of 4 means that instructions were provided for the design of four main elements of the RPD, i.e., shape of major connector, type of direct retainers, position of direct retainers, position of dental rests.

Results:

162 dentists’ prescriptions for RPDs and related casts were assessed. The majority of RPD cases were designed by the dental technician alone (64.2%). Shape of the major connector was the most frequent element in dentists’ prescriptions (35.8%). The mean quality score of dentists’ instructions was 0.96 (sd=1.54). 18% of the provided instructions achieved quality score equal to 4. Prescriptions for Kennedy Class III cases achieved significantly higher mean quality score compared to Kennedy Class II cases (p<0.05). 16.7% of the evaluated casts had clearly defined rest seat preparation.

Conclusion:

The results of this survey indicate inadequate quality of communicating the design features of cobalt chromium RPDs among practicing dentists in Riyadh, Saudi Arabia. The reliance on the dental technician to design the cast RPDs seems to be high.

Patient's Satisfaction with Removable Partial Dentures: A Retrospective Case Series

This retrospective clinical study aimed to assess patient’s satisfaction with removable partial dentures (RPDs), as retention, chewing ability, aesthetics during the observation period.

The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth

OBJECTIVE

The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth.

MATERIALS AND METHODS

A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P < 0.05).

RESULTS

The mean scores for PLI, CI, BOP, PD, and TM index, of the abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05).

CONCLUSIONS

With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases.

A study of dentists' preferences for the restoration of shortened dental arches with partial dentures

OBJECTIVE

This study aimed to use a utility method in order to assess dentists' preferences for the restoration of shortened dental arches (SDAs) with partial dentures. Also, the impact of patient age and length of the SDA on dentists' preferences for the partial dentures was investigated.

MATERIALS AND METHODS

Totally, 104 subjects holding a basic degree in dentistry and working as staff members in a private dental college in Saudi Arabia were interviewed and presented with 12 scenarios for patients of different ages and mandibular SDAs of varying length. Participants were asked to indicate on a standardized visual analog scale how they would value the health of the patient's mouth if the mandibular SDAs were restored with cobalt-chromium removable partial dentures (RPDs).

RESULTS

With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, dentists' average utility value of the RPD for the SDAs was 0.49 (sd= 0.15). Mean utility scores of the RPDs across the 12 SDA scenarios ranged between 0.35 and 0.61. RPDs that restored the extremely SDAs attracted the highest utility values and dentists' utility of the RPD significantly increased with the increase in the number of missing posterior teeth. No significant differences in dentists' mean utility values for the RPD were identified among SDA scenarios for patients of different ages.

CONCLUSION

Restoration of the mandibular SDAs by RPDs is not a highly preferred treatment option among the surveyed group of dentists. Length of the SDA affects dentists' preferences for the RPD, but patient age does not.