ABSTRACT
Introduction:
Interproximal reduction (IPR) is an orthodontic technique used to address space constraints by removing small amounts of enamel between teeth. This research aims to evaluate the impact of IPR on enamel surface integrity, tooth sensitivity, and the long-term stability of orthodontic results.
Methods:
The study was conducted on a sample of 50 patients undergoing orthodontic treatment. Three parameters were evaluated: changes in enamel thickness pre- and post-IPR, post-treatment sensitivity using a visual analog scale, and relapse tendencies measured over a 12-month follow-up. Data were statistically analyzed using paired t-tests.
Results:
Enamel thickness was reduced by an average of 0.25 mm post-IPR (P < 0.05). Mild post-treatment sensitivity was reported by 30% of the patients. Relapse was minimal, with no statistically significant correlation with the extent of IPR performed.
Conclusion:
IPR is a safe and effective method in orthodontic treatment with minimal enamel reduction, mild short-term sensitivity, and no significant long-term relapse. These findings support the continued use of IPR as a conservative approach to space management.
KEYWORDS: Enamel thickness tooth sensitivity, interproximal enamel reduction, orthodontic therapy, relapse tendencies
INTRODUCTION
Interproximal reduction (IPR) involves the removal of small amounts of enamel from interproximal surfaces of teeth to gain space for orthodontic alignment. This technique has become a key component in orthodontic therapy, particularly in cases requiring minor space adjustments. Studies have shown that IPR can effectively reduce crowding, improve tooth alignment, and reduce the need for extractions in orthodontic cases.[1,2,3,4] However, concerns about the potential damage to enamel integrity and long-term dental health remain prevalent.[5,6]
This study aims to evaluate the impact of IPR on enamel thickness, patient-reported sensitivity, and relapse tendencies post-treatment. By utilizing quantitative and qualitative parameters, we intend to provide further insights into the clinical outcomes of IPR and its safety in orthodontic therapy.
METHODS
This study was conducted on 50 orthodontic patients, aged 15–25 years, who required interproximal reduction (IPR) as part of their treatment plan. Enamel thickness was measured before and after IPR using digital calipers. A visual analog scale (VAS) was used to assess post-procedural tooth sensitivity. Relapse tendencies were evaluated over a 12-month follow-up by measuring tooth movement using orthodontic records. Statistical analysis was performed using paired t-tests to compare enamel thickness changes, while sensitivity and relapse data were analyzed using Chi-square tests. Ethical approval was obtained, and informed consent was secured from all participants.
RESULTS
The results presented in Table 1 demonstrate a statistically significant reduction in enamel thickness following interproximal reduction (IPR). The mean enamel thickness before IPR was 2.1 ± 0.3 mm for Group 1 and 2.2 ± 0.2 mm for Group 2. After IPR, the enamel thickness reduced to 1.85 ± 0.4 mm in Group 1 and 1.9 ± 0.3 mm in Group 2. This reduction in both groups was statistically significant, with P values less than 0.05, indicating that IPR effectively decreased enamel thickness without exceeding safe limits. These findings align with prior research, confirming that IPR achieves the intended enamel reduction while maintaining sufficient enamel for long-term tooth health.
Table 1.
Changes in enamel thickness before and after IPR
| Group | Pre-IPR Thickness (mm) | Post-IPR Thickness (mm) | P |
|---|---|---|---|
| Group 1 | 2.1±0.3 | 1.85±0.4 | <0.05 |
| Group 2 | 2.2±0.2 | 1.9±0.3 | <0.05 |
Table 2 highlights the patient-reported sensitivity after undergoing IPR. Out of the 50 patients included in the study, 70% reported no sensitivity following the procedure. Approximately 20% of the patients experienced mild sensitivity, and 10% reported moderate sensitivity. None of the patients reported severe sensitivity. This indicates that while a minority of patients experienced some level of discomfort after IPR, the majority (70%) had no sensitivity issues, and those who did experience discomfort reported it as mild or moderate. These results suggest that IPR is a well-tolerated procedure for most patients, with minimal risk of significant post-procedural sensitivity. The temporary nature of the sensitivity further supports the conclusion that IPR is a safe technique when performed properly.
Table 2.
Patient-reported sensitivity post-IPR
| Sensitivity Score | No. of Patients (n=50) | Percentage (%) |
|---|---|---|
| No Sensitivity | 35 | 70% |
| Mild Sensitivity | 10 | 20% |
| Moderate Sensitivity | 5 | 10% |
DISCUSSION
The present study evaluates the effects of interproximal reduction (IPR) on enamel thickness, post-procedural sensitivity, and relapse tendencies in orthodontic patients. The results demonstrate that IPR is a minimally invasive technique that effectively reduces enamel thickness without compromising long-term dental health. The findings align with previous literature that supports the use of IPR as a conservative approach to space management in orthodontic therapy.[1,2]
One significant observation was the average reduction of 0.25 mm in enamel thickness post-IPR, which is consistent with earlier studies that reported minimal enamel loss within safe limits.[3,4] This level of reduction is considered sufficient to achieve space for tooth movement without increasing the risk of dental caries or structural weakness. However, the process should still be performed with caution to avoid over-reduction, which can negatively impact tooth vitality.[5]
Patient-reported sensitivity following the procedure was mild and transient, with 30% of patients experiencing sensitivity that subsided within two weeks. This is in agreement with previous studies that noted temporary sensitivity post-IPR, likely due to the exposure of more vulnerable areas of enamel.[6] Given that sensitivity did not persist long-term, it can be concluded that IPR does not cause significant pulpal damage, provided the reduction is controlled and monitored carefully.
In terms of relapse, the study observed no statistically significant movement of teeth over a 12-month follow-up period, suggesting that IPR does not increase the likelihood of orthodontic relapse. This reinforces the efficacy of IPR in maintaining post-treatment results and supports its use in cases where space management is needed.[7,8,9,10,11]
While the findings of this study are promising, some limitations should be acknowledged. The relatively small sample size and short follow-up period may limit the generalizability of the results. Future studies with larger populations and longer observation periods are recommended to confirm these findings and further investigate the long-term effects of IPR on enamel health and tooth stability.
CONCLUSION
This study demonstrates that interproximal reduction is an effective and conservative technique for space management in orthodontic therapy. The procedure results in minimal enamel reduction, mild and transient sensitivity, and no significant long-term relapse. These findings suggest that IPR can be safely employed in clinical practice with appropriate case selection and careful technique.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
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